Convergence insufficiency--a major review

Jeffrey Cooper, M.S., O.D., and Nadine Jamal, O.D. Review

KEYWORDS ABSTRACT

OPTOMETRY Convergence Convergence insufficiency is a common binocular vision disorder affecting approximately 5% of the insufficiency; population in the United States. It is often associated with a host of symptoms that occur when doing Accommodation; near work, such as reading and computer viewing. This article reviews the existing literature on Exophoria; convergence insufficiency including etiology, diagnosis, sensorimotor findings, and management. Fusional convergence; Vision therapy; Orthoptics; Prism; Asthenopia; Eyestrain

Definition Epidemiology

Convergence Insufficiency (CI) is a binocular vision disorder, The prevalence of CI is not truly known because no first described by von Graefe¹ in 1855 and later elaborated by population-based studies are available. There is great Duane² and is typically characterized by the following signs: 1) variability in the reported prevalence of CI ranging from exophoria that is greater at near than distance, 2) a remote 1.75 to 33%.4,8-14 with the average prevalence reported to be near point of convergence (NPC), i.e., a breakdown in approximately 5%. This variability can be attributed to convergence greater than 3 inches, or 3) decreased positive differences in the definitions of CI, the sample studied 2,3 fusional convergence (PFC) at near. It often is associated (clinic samples vs general population), and differences in testing with symptoms such as double vision, eyestrain, headaches, protocols (some studies measure near point of convergence blurred vision, and loss of place while reading or performing with a pencil, whereas others use an accommodative target that near work; however, not all patients present with symptoms. may alter measurements). Duane,2 and White and Brown10 reported a prevalence of 7.5% CI. Kratka and Kratka9 reported Throughout the years, and even today, numerous investigators that 25% of patients seen in a general ophthalmologic practice and eye care providers have used various definitions in the had at least 1 finding of CI, and 50% of those who had 1 sign diagnosis of CI. Some have used only a receded NPC to had all 3 signs with further testing. They reported that 75% of 4,5 diagnose CI regardless of phoria or PFC, whereas many their CIs were symptomatic and were diagnosed between the others believe that an exophoria greater at near must be ages of 20 and 40 years. Neither of these studies provided present, along with either a reduced NPC or PFC. Others feel information as to how their population was selected, i.e., that both the NPC and PFC should be reduced in the definition of CI, age, or sex. presence of an exophoria before a definitive CI can be 6 diagnosed. The best population estimates available are from 3 studies of North American school-age children who were tested in their In a clinical study, it was found the 55% of patients had no respective elementary schools.5,15,16 The estimates ranged from signs of CI; 33% had 1 sign; 12% had 2 signs; and 6% had all 3 2.25% to 8.3%. However, the definition of CI was not uniform 6 signs. The most common finding in those patients with a CI, among the studies. Whether the prevalence of CI varies among who did not demonstrate all 3 signs of CI, was a receded ethnic/racial groups is unknown. NPC. In some cases, a CI may be diagnosed in the presence of asthenopia associated with convergence, but in the absence of Many older studies imply that CI is not common in children, a receded near point of convergence, exophoria at near, or because symptoms are not commonly reported until the 3,7 reduced positive relative convergence. The definition of CI second or third decade of life.4,8,13,14 Recently, Wright and has important diagnostic and treatment implications. The Boger17 suggested that symptoms of blur and diplopia found in Convergence Insufficiency Treatment Trial Study Group (CITT children are a result of interpretation of normal physiologic Study Group) has been studying a specific condition in which phenomena. However, they provide no documentation to all 3 signs are present along with symptoms. In this report, we support this position. In addition, if the symptoms were a define this condition as a symptomatic “classic” CI, and consequence of normal physiologic phenomena, one would not patients who do not demonstrate all 3 signs, a “common” CI. expect to find a difference between active vision therapy versus Without consistent diagnostic criteria, studies determining placebo.18 It had been assumed that young adults spend prevalence, characteristics, and treatment results are difficult more time performing near point work than children, thus, to compare. young adults are more likely to complain of symptoms.

© 2012 American Optometric Association. All rights reserved. Recent studies by members of the CITT Study Group have associated with computer use.29,30 found a higher prevalence of CI in children than had been previously assumed.16 Fifth and sixth graders were screened to Sheedy29 and Sheedy and Bergstrom30 surveyed 1,307 op- determine both the presence and severity of CI. These children tometrists to determine the type of symptoms associated with were classified according to the presence and number of the computer use. The most commonly reported symptoms (in following clinical signs: 1) exophoria at near, 2) insufficient order of frequency) were eyestrain, headaches, blurred vision, fusional convergence, and 3) receded near point of con- dry eyes, irritated eyes, neck pain, photophobia, and diplopia. vergence. Twenty-one percent demonstrated some evidence of Sheedy et al31 indicated that two-thirds of the symptoms a CI: 8% had exophoria at near, 9% had exophoria at near with associated with computer use were also associated with an additional clinical sign, and 4% had classical CI with all 3 diagnosable visual anomalies. Computer symptoms associated clinical signs. with dry eye31 resulted in burning or stinging from decreased blink reflex. ( It has been estimated that computer-related visual There are no studies reporting the incidence of CIs in families, complaints cost at least $1.2 billion annually in eye care, which although this author has noticed a strong familial tendency for does not account for decreased work efficiency or quality-of-life CI. issues.29) Because approximately 5% of the population has CI, it would not be surprising that patients with CI make up a Symptoms significant number of symptomatic computer workers. The most frequently reported symptom for CI is discomfort after reading or computer work,8,13,19-21 which usually occurs at One may simulate asthenopia induced by reading or computer the end of the day.13,21 Other symptoms include frontal use by measuring vergence amplitudes with prisms and headaches,11,13 eye ache, a pulling sensation, heavy accommodation with facility tests.3,32 Many patients with eyelids, sleepiness,11 diplopia,8,11-13,22-24 loss of concentration,10,11 symptomatic CI will, when queried, report symptoms found blurred vision,8,13,22,23 tearing,10 and dull orbital pain. Less during or after testing to be similar to those found while reading common complaints include nausea, motion sickness,3 dizziness, or performing other near tasks. 4,8,14 panoramic headaches,8,13,14 gritty sensation in the eyes, and general fatigue. Some CI patients report poor ‘‘depth The association of CI and symptoms in children has been perception,’’ e.g., trouble parking a car or trouble playing tennis.3 investigated by the CITT Group who developed the Two other common complaints noted by patients with CI are Convergence Insufficiency Symptom Survey (CISS).33-35 car sickness and migraines, which, in this author’s experience, The CISS is a questionnaire with 15 questions designed to decrease with therapy. Patients with CI often complain of quantify symptoms associated with reading and near work. Each migraine headaches, which occur immediately after performing question requires a verbal response of ‘‘never, infrequently, excessive near work and after the first few sessions of vision sometimes, fairly often, and always.’’ The highest possible score therapy. However, these migraines disappear with treatment. is 60, and the lowest possible score is 0 (see Appendix 1 for the Thus, it might be presumed that in some patients with CI, questionnaire). extensive close work triggers migraine episodes.25 Symptoms were measured prospectively on school-age (8–13 Because there are no population studies of children or adults years) children with CI and children with normal binocular showing objective findings of CI, the true prevalence of vision (controls).34 The mean (± standard deviation [SD]) CI asymptomatic CI is unknown. In the only large-scale, randomized Symptom Survey score for the children with CI was 30.8 ± 8.4, clinical trial of CI in children, the 5 most frequently reported whereas for the children with normal binocular vision, the score symptoms were ‘‘loses place while reading’’ (49.8%), ‘‘loses was 8.4 ± 6.4. Good discrimination (sensitivity, 96%; specificity, concentration while reading’’ (45.3%), ‘‘needs to reread the same 88%) was obtained using a score of >16. Thus, children with CI line of words when reading’’ (44.8%), ‘‘reads slowly’’ (40.3%), and showed a significantly higher CISS score than children with ‘‘has trouble remembering what was read’’ (38.0%).26 normal binocular vision. Additionally, Borsting et al.33 compared patients who responded to each question (symptom) ‘‘fairly Hirsch27 reported that 38% of 48 university students referred often’’ and ‘‘always’’ with CI and those having normal binocular for treatment for CI complained of eyes tiring and sleepiness vision. It is readily apparent when looking at Figure 1 that for after doing close work for any considerable length of time, 35% each symptom there is a significant difference between the CI experienced headaches, and 18% experienced stinging or group and normal subjects. These differences between ‘‘normals’’ burning of the eyes. Kent and Steeve11 reported that 60% of and CIs should dispel the notion that symptoms are related to a their patients with CI had headaches, 49% experienced blurring child’s interpretation of normal physiologic phenomena. of print, 34% had ocular fatigue, and 21% had intermittent diplopia. As expected, many patients had more than 1 symptom. The CISS was also used to evaluate symptoms in adults age 19 Burian,23 in a small study, reported that 18% of patients with CI to 30 years by comparing a group with symptomatic CI with are asymptomatic. The absence of symptomatology has been those with normal binocular vision.35 The mean CI Symptom presumed to be because of either suppression,5 avoidance of Survey scores were 37.3 ± 9.3 and 11.0 ± 8.2 for CI and the near visual tasks,28 high pain threshold, or monocular occlusion. normal binocular vision groups, respectively. Good Symptoms associated with CI may negatively affect a person’s discrimination (sensitivity, 97.8%; specificity, 87%) was obtained quality of life by interfering with school, work, and leisure using a cutoff score of ≥21 for adults. This cutoff score was activities performed at near. higher than the cutoff of 16 found for children with symptoms. Figure 2 depicts the incidence of each symptom in children and These studies were all performed before the rapid increase in adults. In general, adults reported a higher frequency of computer use. Currently, the leading reason patients make occurrence for each symptom on the CISS. The pattern of appointments for eye examinations is because of symptoms response differed between children and adults on 6 of the CISS Cooper and Jamal Literature Review 3

217 were also associated with diagnosable visual anomalies. 274 218 Computer symptoms associated with dry eye31 resulted in 275 219 burning or stinging from decreased blink reflex. (It has 276 220 been estimated that computer-related visual complaints 277 221 costCooper at least and 1.2Jamal billion Literature dollars annually Review in eye care, which 3 278 222 does not account for decreased work efficiency or quality- 279 of-life issues.29) Because approximately 5% of the popula- 223217 were also associated with diagnosable visual anomalies. The280274 results of these studies suggest that the CISS is a valid and

224 tion has CI, it would not be surprising that patients31 with CI FPO reliable281 instrument that can be used clinically or as an outcome 218 Computer symptoms associated with dry eye resulted in = 275 make up a significant number of symptomatic computer measure for research studies for patients with CI. However, all 225219 burning or stinging from decreased blink reflex. (It has 282276 226 workers. scaled283 symptom questionnaires have some limitation. They are 220 been estimated that computer-related visual complaints sensitive277 when symptoms of asthenopia are diverse, e.g., patient 227 One may simulate asthenopia induced by reading or 284 221 cost at least 1.2 billion dollars annually in eye care, which has278 headaches, double vision, loss of concentration, but not when 228 computer use by measuring vergence amplitudes with the285 patient exhibits only 1 symptom, e.g., diplopia. If a patient only 222 does not account for decreased work efficiency3,32 or quality- 279 229 prisms and accommodation29 with facility tests. Many pa- has286 1 symptom that occurs all the time, then the symptom 223 of-life issues. ) Because approximately 5% of the popula- print & web 4C 280 230 tients with symptomatic CI will, when queried, report score287 would only be equal to 5, and the patient would be

224 tion has CI, it would not be surprising that patients with CI Figure 1 Symptoms of patients with normal binocular vision (NBV) and FPO 281 231 symptoms found during or after testing to be similar to = considered288 statistically normal. Elimination of the symptom by 225 make up a significant number of symptomatic computer CI. The CISS was administered to subjects with NBV and subjects with a CI. 282 232 those found while reading or performing other near tasks. Mean scores for each question are presented for both the CI and NBV therapy289 would only result in a decrease of 5 points on the CITT 226 workers. questionnaire.283 Thus, clinically, one must use the questionnaires 233 The association of CI and symptoms in children has group. Subjects with NBV and CI have clinically different scores on each 290 227 One may simulate asthenopia induced by reading or of the 15 questions. (Revised from Borsting et al.34) with284 these limitations in mind. Even with this limitation, we 234 been investigated by the CITT Group who developed the suggest291 that the CISS be used diagnostically to detect and quantify 228 computer use by measuring vergence amplitudes33-35 with 285 235 Convergence Insufficiency Symptom Survey3,32 (CISS). 292 229 prisms and accommodation with facility tests. Many pa- CI286 before treatment and after treatment to measure change. 236 The CISS is a questionnaire with 15 questions designed sore eyes, pulling around the eyes (P 5 0.003) and blurri- print &293 web 4C 230 tients with symptomatic CI will, when queried, report 287 237 to quantify symptoms associated with reading and near nessFigure when 1 readingSymptoms or of doing patients near withwork. normal binocularThe most vision frequently (NBV) and Sensorimotor294 findings 231 symptoms found during or after testing to be similar to 288 238 work. Each question requires a verbal response of ‘‘never, reportedCI. The CISS symptom was administered among to children subjects with was NBV loss and of subjects place with while a CI. 295 232 those found while reading or performing other near tasks. FigureMean scores1 Symptoms for each of questionpatients with are presentednormal binocular for both vision the CI (NBV) and NBV Phoria289 239 infrequently, sometimes, fairly often, and always.’’ The reading or performing near work; 58% reported that loss of 296 233 The association of CI and symptoms in children has andgroup. CI. SubjectsThe CISS with was NBV administered and CI have to clinicallysubjects with different NBV scores and subjects on each 290 240 highest possible score is 60, and the lowest possible score place occurred fairly often or always. This was34 followed by 297 13 234 been investigated by the CITT Group who developed the withof thea CI. 15 Mean questions. scores(Revised for each from questionBorsting are presented et al. ) for both the CI Passmore291 and MacLean noted that 79% of their patients with CI 241 is 0 (see Appendix 1 for the questionnaire). 33-35 sleepiness (48%) and reading slowly (47%). In contrast, 298 235 Convergence Insufficiency Symptom Survey (CISS). and NBV group. Subjects with NBV and CI have clinically different had292 exophoria at near, 18% had orthophoria, and 3% had 242 Symptoms were measured prospectively on school-age scores‘‘eyes on feelingeach of the tired’’ 15 questions. was the (Revised most from frequently Borsting et al. reported34) esophoria.299 Cushman and Burri36 reported that 63% of CI patients 236 The CISS is a questionnaire with 15 questions designed sore eyes, pulling around the eyes (P 5 0.003) and blurri- 293 243 (8–13 years) children with CI and children with normal symptom by adults (72%) followed by ‘‘eyes feeling exhibited300 an exophoria on cover testing at near. In the CITT (N 237 to quantify symptoms associated with reading and near ness when reading or doing near work. The most frequently 294 Δ 244 binocular vision (controls).34 The mean (6 standard devia- uncomfortable’’ (70%). =301 221) the mean (SD) clinical findings were 2 (2.84) 238 work. Each question requires a verbal response of ‘‘never, reported symptom among children was loss of place while exodeviation295 at distance and 9.3Δ (4.4) exodeviation at near. These 245 tion [SD]) CI Symptom Survey score for the children with items.The Adults results reported of these a higher studies frequency suggest of thattired theeyes, CISS is a 302 239 infrequently, sometimes, fairly often, and always.’’ The uncomfortablereading or performing eyes, eyes that near hurt, work; sore 58% eyes, reported pulling around that loss the of findings296 were not derived from population studies; however, most 246 CI was 30.8 6 8.4, whereas for the children with normal valid and reliable instrument that can be used clinically or 303 240 highest possible score is 60, and the lowest possible score eyesplace (P = occurred0.003) and fairly blurriness often when or always. reading This or doing was followed near work. by of 297the patients with CI had an exophoria. The presence of 247 binocular vision, the score was 8.4 6 6.4. Good discrimina- as an outcome measure for research studies for patients 304 241 is 0 (see Appendix 1 for the questionnaire). Thesleepiness most frequently (48%) reported and reading symptom slowly among (47%). children In was contrast, loss abnormal298 exophoria at near is not necessary for the diagnosis of 248 tion (sensitivity, 96%; specificity, 88%) was obtained using with CI. However, all scaled symptom questionnaires have common305 CI. 242 Symptoms were measured prospectively on school-age of ‘‘eyesplace while feeling reading tired’’ or performing was the near most work; frequently 58% reported reported 299 249 a score of .16. Thus, children with CI showed a signifi- thatsome loss limitation.of place occurred They fairly are often sensitive or always. when This symptoms was of 306 243 (8–13 years) children with CI and children with normal symptom by adults (72%) followed by ‘‘eyes feeling 300 250 cantly higher CISS score than children with normal binoc- followedasthenopia by sleepiness are diverse, (48%) e.g., and patientreading hasslowly headaches, (47%). In double Fusional307 convergence 244 binocular vision (controls).34 The mean (6 standard devia- uncomfortable’’ (70%). 301 251 ular vision. Additionally, Borsting et al.33 compared contrast,vision, “eyes loss feeling of concentration, tired’’ was the butmost not frequently when thereported patient 308 245 tion [SD]) CI Symptom Survey score for the children with symptomThe by results adults of(72%) these followed studies bysuggest ‘‘eyes feeling that the CISS is a The302 majority of patients with CI have insufficient PFC 252 patients who responded to each question (symptom) ‘‘fairly exhibits only 1 symptom, e.g., diplopia. If a patient only 309 3,14,22 2 246 CI was 30.8 6 8.4, whereas for the children with normal uncomfortable’’valid and reliable (70%). instrument that can be used clinically or amplitudes303 at near. Duane stated that a CI ‘‘frequently (had) 253 often’’ and ‘‘always’’ with CI and those having normal bin- has one symptom that occurs all the time, then the symptom 310 Δ 247 binocular vision, the score was 8.4 6 6.4. Good discrimina- as an outcome measure for research studies for patients decreased304 abduction of 5° to 6° (~8–10 ), but not more than 9° 254 ocular vision. It is readily apparent when looking at 311 tion (sensitivity, 96%; specificity, 88%) was obtained using with CI. However, all scaled symptom questionnaires have (~15Δ), prism convergence usually decreased to 8° to 12° (~14 248 305 13 255 Figure 1 that for each symptom there is a significant differ- some limitation. They are sensitive when symptoms of 20312Δ) or less.’’ Furthermore, Passmore and MacLean considered 249 a score of .16. Thus, children with CI showed a signifi- 306 21 256 ence between the CI group and normal subjects. These dif- asthenopia are diverse, e.g., patient has headaches, double fusional313 amplitudes measuring 8 to 10D to be low, Mayou 250 cantly higher CISS score than children with normal binoc- regarded307 10 to 20D to be low, Hirsch27 regarded 12D to be low, 257 ferences between ‘‘normals’’ and CIs should33 dispel the 314 251 ular vision. Additionally, Borsting et al. compared vision, loss of concentration, but not when the patient 308 19 258 notion that symptoms are related to a child’s interpretation and315 Mould regarded 15D to be low. In the CITT, the mean (SD) 252 patients who responded to each question (symptom) ‘‘fairly exhibits only 1 symptom, e.g., diplopia. If a patient only positive309 fusional convergence break/recovery at near was 12.7 259 of normal physiologic phenomena. 316 253 often’’ and ‘‘always’’ with CI and those having normal bin- has one symptom that occurs all the time, then the symptom (64.69)310 Δ /8.8 (64.5)Δ. PFC of less than 15D would be con- 260 The CISS was also used to evaluate symptoms in adults 317 254 ocular vision. It is readily apparent when looking at sidered311 abnormal for patients with CI and the general pop- 261 age 19 to 30 years by comparing a group with symptomatic 318 37-39 255 Figure 1 that for each symptom there is a significant differ- ulation.312 Low PFC is associated with asthenopic symptoms. 262 CI with those with normal binocular vision.35 The mean CI Variability319 in measurement of PFC occurs with the stimuli used;

256 ence between the CI group and normal subjects. These dif- FPO 313 263 Symptom Survey scores were 37.3 6 9.3 and 11.0 6 8.2 = for320 example, size, illumination, speed of measurement, and 257 ferences between ‘‘normals’’ and CIs should dispel the 314 40 264 for CI and the normal binocular vision groups, respectively. instructional321 set all affect PFC. However, when using a large 258 notion that symptoms are related to a child’s interpretation fusional315 stimulus, presented under the same conditions, 265 Good discrimination (sensitivity, 97.8%; specificity, 87%) 322 259 of normal physiologic phenomena. measurements316 are fairly repeatable.41 Repeatability decreases 266 was obtained using a cutoff score of R21 for adults. This 323 260 The CISS was also used to evaluate symptoms in adults with317 smaller targets, such as the single line of letters used with 267 cutoff score was higher than the cutoff of 16 found for chil- traditional324 phorometric testing.42,43 It should be noted that the 261 age 19 to 30 years by comparing a group with symptomatic 318 268 dren with symptoms. Figure 2 depicts the incidence of each print &measurements web325 4C do not account for the effort expended; thus, it is CI with those with normal binocular vision.35 The mean CI 262 Distribution of symptoms in CI in children and adults. The not319 uncommon for symptomatic patients in whom symptoms 269 symptom in children and adults. In general, adults reported Figure 2 FPO 326 263 Symptom Survey scores were 37.3 6 9.3 and 11.0 6 8.2 = 320 270 a higher frequency of occurrence for each symptom on the CISS was administered to both children and adults. Mean scores for each from327 testing develop to have normal amplitude measurements. 264 for CI and the normal binocular vision groups, respectively. question are presented for both the CI and normal binocular vision group. Fusional321 recovery consists of voluntary convergence and 271 CISS. The pattern of response differed between children Figure 2 Distribution of symptoms in CI in children and adults. The 328 265 Good discrimination (sensitivity, 97.8%; specificity, 87%) Generally, adults have more severe symptoms especially with regard to convergence322 in response to spatial disparity. Hirsch27 reported 272 and adults on 6 of the CISS items. Adults reported a higher CISS was administered to both children and adults. Mean scores for each 329 266 was obtained using a cutoff score of R21 for adults. This questionasthenopia are presented versus symptoms to both related the CI toand reading. normal(Revised binocular from visionBorsting group. that323 the recovery finding is low in patients with CI. Cooper and 273 frequency of tired eyes, uncomfortable eyes, eyes that hurt, et al.34 and Roust et al.35) Duckman330 3 suggested that the recovery point is probably a better 267 cutoff score was higher than the cutoff of 16 found for chil- Generally, adults have more severe symptoms especially with the regard to 324 asthenopia versus symptoms related to reading (Revised from Borsting et indication of fusional potential over time. The recovery 268 dren with symptoms. Figure 2 depicts the incidence of each print & web325 4C al. 34 and Roust et al35.) represents the patient’s ability to voluntarily regain fusion on the 269 symptom in children and adults.FLA In 5.1.0general, DTD adultsŠ OPTM1143_proof reported ŠFigure3 December 2 Distribution 2011 Š 1:30 ofsymptoms pm in CI in children and adults. The basis326 of sensory information. 270 a higher frequency of occurrence for each symptom on the CISS was administered to both children and adults. Mean scores for each 327 question are presented for both the CI and normal binocular vision group. 271 CISS. The pattern of response differed between children Generally, adults have more severe symptoms especially with regard to 328 272 and adults on 6 of the CISS items. Adults reported a higher asthenopia versus symptoms related to reading. (Revised from Borsting 329 273 frequency of tired eyes, uncomfortable eyes, eyes that hurt, © 2012et al. 34Americanand Roust Optometric et al.35) Association. All rights reserved. 330

FLA 5.1.0 DTD Š OPTM1143_proof Š 3 December 2011 Š 1:30 pm There is a paucity of data regarding slow vergence or vergence symptoms and the type of target in this study was with the adaptation in symptomatic CI.44 However, it is currently penlight with red-green glasses. Scheiman et al.51 suggest that believed that asymptomatic CI patients have normal slow the NPC should be evaluated routinely with an accommodative vergence, whereas patients with symptomatic CI have reduced target. If the NPC is normal, but there are other signs or slow vergence.45,46 symptoms of convergence insufficiency, or if the NPC is borderline (reduced break, recovery, or a large difference Near point of convergence between the 2), the NPC should be repeated with a penlight with red-green glasses. Pang et al.52 have reported similar The near point of convergence is the point to which the lines of findings. The NPC measured with a red lens in front of 1 eye sight are directed when convergence is at its maximum. with a transilluminator was the most sensitive and specific According to Duane,2 a receded NPC (NPC .3 inches or 7.5 testing method to elicit a diagnosis of CI. Use of a cm) is the most consistent clinical sign found in persons with transilluminator or accommodative targets to measure the CI. In a clinical sample of 8 to 12-year-old children with NPC is slightly less sensitive than measurements with a red lens exophoria at near who also had 1 clinical sign of CI, a receded and a transilluminator. Lastly, measurements with either a NPC was a more common finding than reduced PFC (27% vs transilluminator or an accommodative target yielded similar 17%). Thus, it is frequently used to make the diagnosis of CI, findings for both normal and CI subjects. often as the sole means of diagnosing the condition.5,6 Various investigators have reported different pass/fail criteria including 53 13.1 cm,17 9.5 cm,2 and 7.5 cm (3 inches).47 Maples and Using a standardized protocol, Hayes et al. established normative values for NPC in 297 children in kindergarten, Hoenes48 reported that the NPC break and recovery does not change significantly with multiple measurements during the third, and sixth grades who passed a Modified Clinical same testing session. They suggested that the criterion for an Technique vision screening. Moving a single column of 20/30 NPC break score to differentiate symptomatic from less letters at a rate of approximately 1 to 2 cm/s toward the symptomatic elementary school children should be 5 cm or patient’s eyes and measuring from the center of the forehead at more. the brow, the NPC break was determined as the mean of 3 measures in which either the examiner observed 1 eye deviate Although the NPC is an easy clinical test to administer, there or the subject reported diplopia, whichever occurred first. At has not been consensus on how the test should be performed, least 85% of the subjects in each grade had an NPC break ≤6 with methodology varying from study to study. Variables cm. The mean (±SD) NPC break values for kindergarten was 3.3 (±2.6), for third graders was 4.1 (±2.4), and for sixth graders include the type (e.g., penlight, ruler, accommodative target) and 53 size of the fixation target, the point from which the NPC is was 4.3 (±3.4). Based on their findings, Hayes et al. measured (e.g., spectacle plane, bridge of nose, corneal plane, recommend a clinical cutoff value of ≤6 cm for school-age center of rotation of eyes), speed of moving the target, and children. whether the patient’s subjective response of diplopia or the 51 examiner’s observation of when an eye deviates is used to Scheiman et al. suggested that a clinical cutoff for determine the NPC break and recovery points. Assuredly, these adults should be 5 cm for the NPC break and 7 cm for variations in technique have contributed to the wide variations the recovery. Other studies have used values ranging from in pass/fail criteria. 5 to 11 cm for the break, and 8 to 11 cm for the recovery. 2,3,10,50 It should be noted that the Scheiman et al.51 Davies20 recommended that the NPC be performed 12 times to finding of ≤5 cm as the expected break value for normal produce ocular fatigue. According to Davies, symptomatic CI subjects compares favorably with the expected break value patients will show a decrement of the NPC with repetition, of ≤6 cm for children found by Hayes et al.53 whereas asymptomatic patients may not. Capobianco49 suggested that the NPC in CIs would recede when a red lens is Near point analysis placed in front of an eye when the NPC was repeated numerous times. During NPC testing, it is common to see head In 1893, Maddox54 described the 3 components of the retraction, sweating, facial grimaces, and wrinkling of the vergence system that were thought to be additive: tonic, forehead in patients with CI.3,50 This may be indicative of the accommodative, and proximal, which included voluntary and amount of effort used by the patient to initiate convergence. fusional.54 More recent information has shifted the paradigm This response, in this author’s experience, is almost diagnostic from the Maddox model to a negative feedback control system of symptomatic CI. The test should always be performed with analysis,44,55-58 in which closed loop feedback from the patient actively trying to converge as much as possible. accommodative blur and disparity vergence work to reduce the errors of blur and diplopia. Disparity (i.e., fusional) vergence is Scheiman et al.51 measured the near point of convergence 3 made up of 2 components, a fast component, which responds to ways: with an accommodative target, a penlight, and a penlight immediate vergence demands, and a slow adaptive vergence with red and green glasses. The near point of convergence was component with a long time decay, which is responsible for also measured using a penlight for 10 repetitions. They reported maintaining vergence over a long period of time. that the clinical cutoff value for the near point of convergence The fast vergence system, which eliminates the initial disparity break was 5 cm and 7 cm for the near point of convergence vergence error, is evaluated with clinical measurements of recovery with either an accommodative target or a penlight fusional vergence amplitudes using prism. Slow adaptive with red and green glasses. The use of a pen light with red-green vergence, which eliminates the long-term demand on disparity glasses or repetition of the NPC appears to be more sensitive vergence, is evaluated with prolonged occlusion or repeated in the diagnosis of subtle cases of convergence insufficiency. A alternate occlusion and is not normally measured by the difference of more than 4 cm between the first and tenth clinician. However, the amount of slow vergence may be repetition suggests a problem. The highest correlation between inferred by noting the difference between the unilateral and alternate cover tests, the diffeence between the initial and final eliminate diplopia and visual confusion by creating functional alternate cover test, or the shape of the fixation disparity curve. monocular vision. In our opinion, the more severe the CI and 59 Patients with ‘‘strong’’ vergence adaptation (slow vergence) the longer the CI has been manifest, the greater the probability have a flatter fixation disparity curve and are presumed to have of suppression with a resultant lack of symptoms. fewer symptoms than patients with steeper curves, whereas symptomatic patients have been found to have poor vergence Reading is one of the few ‘‘real-life’’ flat fusion tasks. The loss of adaptation and steeper fixation disparity curves.59,60 retinal disparity cues in reading may result in a poorer stimulus for binocular alignment, and this may account for patients with Many investigators have attempted to relate phoria CI experiencing symptoms while reading or using the computer magnitude (demand) to positive fusional convergence. but not while performing other near tasks.3 Duke-Elder8 felt that only one-third of the total convergence should be used at 33 cm; therefore, 54△ of convergence should Refractive error be on reserve for maximum expenditure. Sheard61 and Hofstetter37 believed the reserves should be larger than twice There is no correlation between refractive error and the demand. In their studies, Sheedy and Saladin38,63 reported CI.14,22,71,72 Passmore and MacLean13 found that 52% of their CI that using Sheard’s criterion was the best method to distinguish sample was hyperopic, 34% myopic, and 14% emmetropic. between symptomatic and asymptomatic exophores. Smith72 evaluated the refractive error in patients with CI and found that 38% had low myopia, 57% were emmetropic (±1.00 Despite the differences in analyses, there is agreement that the D), and 5% had hyperopia >1.00 D. In another study, Hirsch27 fusional vergence amplitudes must be larger than the demand found 61% of CI patients had ametropia of 0.75 D or less. In the (i.e., magnitude of the phoria) to avoid ocular fatigue. None of CITT, the mean spherical equivalent refractive error was less the methods of analysis account for the variables, such as than 0.50 D.73 These findings are similar to those in the normal amount of conscious effort used to fuse the vergence stimulus, population, suggesting that there is no relationship between amount of time spent on near work, pain threshold, or type of refractive error and CI. work. Thus, a truck driver with identical vergence findings might not be expected to manifest the same symptoms as a Relationship to learning/attention lawyer who works for long periods of time on a computer. Although the exact relationship of CI and learning has not Accommodation been established, it has been implicated as a causative factor for reading deficiencies. Eames74-76 compared good Poor accommodation has been implicated as a possible readers with poor readers and found that CI was more cause of CI. Prakash et al.64 reported that accommodation prevalent in poor readers. Similar findings have been reported was reduced in 23% with CI. Von Noorden et al.,65 Bugola,66 by Park and Burr.77 and Raskind67 have reported that in a few cases in which CIs did not respond to conventional convergence therapy, Recently, Granet et al.78 performed a retrospective study on accommodative amplitudes were the cause, and these patients 266 students with CI diagnosed within an academic pediatric obtained symptomatic relief with plus lenses for near and BI ophthalmology practice. Twenty-six patients (9.8%) had ADHD prism. previously diagnosed (parental report only). Of those having a diagnosis of CI and ADHD, 77% were on medication. Granet et Cooper et al.39 pointed out that recruitment of patients with CI al.78 pointed out that there was a 3-fold greater prevalence of was challenging when an eligibility criterion of normal ADHD among patients with CI compared with the general US accommodation was used. The majority of those failing their population (1.8%–3.3%). The authors suggested that patients criterion had normal amplitudes but showed abnormal with ADHD should have an eye examination to identify the accommodative facility on the ± 2.00 diopter (D) flipper test. possibility of a concomitant CI. Rouse et al.16 reported that the frequency of subjects failing accommodative facility testing increased with the number of CI- In another study, Borsting et al.79 evaluated the frequency related signs. For CI children with 3 signs (classic CI), 78.9% of ADHD behaviors in school-age children with symptomatic were classified as also having an accommodative anomaly. accommodative dysfunction or CI. They reported that using the Marran et al.68 believes that the symptoms found in most CIs Conner’s Parent Rating Scale-Revised Short Form (CPRS-R:S), are secondary to accommodative anomalies. cognitive problem/inattention, hyperactivity, and ADHD index were significantly different than normative values for their Analysis of all the CITT studies found that approximately 58% subjects. The results from their preliminary study suggested of children69 and 39.1% of adults enrolled in the pilot CITT had that school-age children with symptomatic accommodative accommodative insufficiency (AI) using the Hofstetter dysfunction or CI have a higher frequency of behaviors related definition, i.e., accommodative amplitude in diopters is less than to school performance and attention as measured by the CPRS- 2 D from age-expected norms.70 Thus, the majority of children R:S. with a diagnosis of CI have an accompanying AI , which should be addressed with treatment. Although CI is more prevalent in children with learning problems, this does not demonstrate cause and effect. Even Sensory fusion though they may be neurologically related, eliminating CI may or may not have an effect on reading. This is subject to further Generally speaking, patients with CI have normal stereopsis (40 study. seconds of arc or better) on both contour and random dot stereograms.39 Abnormal suppression on first-degree targets is common in CI and may serve as a sensory adaptation to Etiology investigators feel that CI is of psychogenic origin, there is no evidence to support this claim other than ‘‘neurotic’’ patients Duke-Elder8 listed the following as possible causes of CI: wide often manifest symptoms or verbalize symptoms to a greater interpupillary distance, delayed development or poorly degree than ‘‘nonneurotic’’ patients. developed accommodation or convergence, presbyopia, disease or debility, toxemia, endocrine disorders, and anxiety neurosis. Most CIs present without a known systemic or psychological Raskind67 noted a small group of CIs secondary to systemic etiology. Symptomatic CI results from a breakdown of disorders, including head trauma, encephalitis, drug intoxication, accommodative convergence cross-links, fusional convergence, malnutrition, debility, hepatitis, and mononucleosis. Although or voluntary convergence interactions.44 There is significant uncommon, CI can also be secondary to anoxia or heavy evidence that the primary culprit is not fast vergence, as tobacco use.80 Patients with a high exophoria who have previously assumed, but slow adaptive vergence, which takes the diseases that interfere with normal binocular vision, such as load off sustained fast vergence.56,59,90 In any case, there is a cataracts, may demonstrate a gross convergence insufficiency breakdown in binocular vision resulting in ocular fatigue. after cataract surgery.81 Recently, there have been reported cases of CI being diagnosed after laser in situ keratomileusis, During near-point tasks, the eyes must maintain a constant and resulting in symptoms that leave the patient dissatisfied with the delicate balance between accommodation and convergence surgical result.82 Thus, binocular status should be evaluated while performing close work. Secondly, accommodation and before recommending cataract surgery, laser in situ kerato- convergence must maintain a stable position during near work. mileusis, or any other refractive procedure. Third, retinal disparity or stereo cues are reduced during reading, possibly making it more difficult for the eyes to Adults with presbyopia often have a large exophoria as a maintain fusion. These 3 factors in combination may explain the result of age-related loss of amplitude of accommodation ocular fatigue that patients with CI experience when secondary to the accommodative-convergence linkage convergence is deficient. Lastly, there might be a genetic (ACA ratio).8 In addition, exophoria may even increase as a component because the condition result of the base-out prism induced in the spectacle reading is often found in families.3 addition. Although one would expect a multitude of symptoms with ensuing presbyopia, the complaints are relatively few.83 To Although the majority of CIs are idiopathic, a large number of offset this induced exo deviation, the presbyopic patient must patients with CI have other concomitant ocular and neurologic substitute disparity-driven fusional vergence for accommodative anomalies. A CI may result from a head trauma, such as incurred vergence. Over a short period, slow adaptive vergence in automobile accidents or gun shot wounds,91-95 and can be increases, eliminating the load on the fast, disparity vergence associated with longer periods of coma (P < 0.001), presence of system. If this occurs, the vergence demand decreases, and the cognitive disturbances (P < 0.005), and patients’ failing to find presbyopic patient remains relatively asymptomatic.59 Patients work in the open market (P < 0.01).93,94 These relationships do who do not have a compensating slow adaptive vergence not necessarily imply cause and effect. The associated findings mechanism may experience symptoms. or symptoms of CI may represent damage to nearby areas in the brain associated with these functions.93 Cohen More women than men present with CI in a ratio of et al. believed that vergence anomalies, which are commonly 3:2,12,22,84,85 However, this might be a result of women associated with brain injury, are an expression of permanent seeking optometric or medical care more often.86 The damage to the mesencephalic and cortical brain structures93,94 CITT studies suggest a more equal incidence of CI among Acquired brain injury consists of 2 major subgroups: traumatic men and women. brain injury (TBI) and cerebral vascular accidents (CVA).96 In a retrospective analysis of the patients referred to an optometric The implication that CI is caused by weak eye muscles clinic with acquired brain injury, the most common diagnosis or other mechanical difficulties has not been demonstrated. was symptomatic CI. Further analysis of the subgroups found A small study by Jampolsky87 noted that CI was most often the that 43% of the patients with TBI and 35% of the patients with result of poor accommodation. It should be noted that the CVA had symptomatic CI.96 high correlation of accommodative anomalies associated with CI may be indicative of general anomalies in both Recently, several investigators97,98 reported a very high accommodation and vergence without implicating etiology. prevalence of CI in wounded soldiers returning from wars in Iraq and Afghanistan. Brahm et al.97 performed a Some investigators feel that CI is psychogenic.50,85,88,89 retrospective study of TBI sustained while serving in the United Only 2 investigators have evaluated the relationship between States military in Iraq and Afghanistan. They evaluated the psychological problems and Cl.71,88 Mellick71 compared the relationship of penetrating versus nonpenetrating injuries results of treatment of ‘‘normal CI’’ and ‘‘neurotic CI.’’ He and individuals with moderate to severe polytraumatic TBIs reported that 77% of his ‘‘neurotics’’ were cured, 8% improved, versus mild TBI. For those with moderate/severe TBI, regardless and 14% had no change. In the normal group, 78% were cured, of whether induced by a blast, the incidence of CI was 15% improved, and 5% showed no improvement as a result of approximately 43%. Patients with milder TBI had a greater treatment. He concluded that there was no significant incidence of reading difficulties and a larger incidence of CI. difference between groups. However, one might conclude that if When the data for the milder CI were further analyzed by CI was caused by neurosis, then one would not expect a nonblast versus blast-related injuries, the incidence of CI was treatment cure rate to be the same as that in normals. 64% and 47%, respectively. Also, nonblast patients with TBI showed a high percentage of AI (74%). Unfortunately, the It is important to note, however, that Mellick did not state how authors did not present data indicating what percentage of the he assessed or measured these neurotic tendencies. Also, patients with CI also had AI. From their data, one may conclude correlations do not imply cause and effect. Although some that CI, AI, and perceived reading difficulties often are associated

© 2012 American Optometric Association. All rights reserved. 8 Optometry, Vol -, No -, - 2012

787 suchwith TBI as whether Duane’s mild syndrome. or severe. In In addition, addition, Goodrich CI has et been al.98 844 reported a CI prevalence of 30% in 50103,104 soldiers with TBI and 788 observed with99 Parkinson’s disease, and left middle 845 Stelmack et al. found a CI105 prevalence of 28% of 103 soldiers 789 cerebralwith TBI. artery occlusion. It is of interest that conver- 846 790 gence insufficiency associated with Parkinson’s improves 847 791 withThe administrationmost common ocular of levodopa. motor disturbance104 associated 848 100 792 with Graves disease is CI. CI occurs relatively early, be- FPO 849 = 793 fore most patients with thyroid-related eye disease present 850 794 Treatmentwith any other signs of noncomitancy. Treatment at this 851 stage, in this author’s experience, is successful. Rarely, CI 795 has been the presenting sign of myasthenia gravis.101,102 852 796 HowCI has do also optometrists been associated and with ophthalmologists other binocular anomalies 853 797 such as Duane’s syndrome. In addition, CI has been observed 854 treat CI? print & web 4C 798 with Parkinson’s disease,103,104 and left middle cerebral artery 855 105 Figure 3 Treatment patterns for CI for optometrists and ophthalmolo- 799 occlusion. It is of interest that convergence insufficiency gists. This figure depicts the percentage of either optometrists or ophthal- 856 Inassociated a survey with of 300Parkinson’s San Francisco improves Baywith administration area optometrists, of 106 800 Figuremologists 3 Treatment recommending patterns each for treatment.CI for optometristsBoth and optometrists and 857 Q7 Scheimanlevodopa.104et al.106 reported that the 2 most commonly pre- 801 ½ Š ophthalmologists.ophthalmologists mostThis oftenfigure recommenddepicts the push-uppercentage treatment of either for patients 858 scribed treatments for CI were pencil push-up therapy 106 802 optometristswith symptomatic or ophthalmologists CI as the treatment recommending of choice. Aeach much treatment. smaller percent- 859 (34%)Treatment and vision therapy/orthoptics (22%), followed by age of optometrists and ophthalmologists advocated the use home vision 803 Both optometrists and ophthalmologists most often recommend push- 860 base-in prism (20%), referral (18%), and no treatment uptherapy/orthoptics. treatment for patients with symptomatic CI as the treatment of 804 How do optometrists and ophthalmologists 861 (6%). choice. A much smaller percentage of optometrist and 805 treat CI? point of convergence carried out simply by the subject 862 In a recent survey to determine treatment patterns for CI ophthalmologists advocated the use of home vision therapy/ 806 orthoptics.holding a target at arm’s length and then gradually bringing 863 patients,In a survey 863 of 300 randomly San Francisco selected Bay area U.S. optometrists, optometrists and 807 it toward the eye, all the time maintaining bifoveal fixation. 864 ophthalmologistsScheiman et al.106 reported were asked that whatthe 2 most treatment commonly they pre- would 808 These exercises should be carried out several times each 865 prescribescribed treatments for a motivated for CI were teenage pencil patientpush-up withtherapy a classic Treatment options 809 day for a few minutes.’’108 The use of a background target 866 symptomatic(34%) and vision CI therapy/orthoptics who was willing (22%), to dofollowed whatever by base-in was 810 prism (20%), referral (18%), and no treatment (6%). Home-basedto provide feedback pencil regarding push-ups. physiologic The basic diplopiapencil push-up appreci- 867 necessary to eliminate his symptoms.106 Fifty-eight percent 811 techniqueation istypically often prescribed, recommended as described by to Duke-Elder control years for 868 of the optometrists and 23% of the ophthalmologists ago, is comprised of ‘‘exercises to improve the near point of 812 In a recent survey to determine treatment patterns for CI suppression.18,106,109,110 869 respondedpatients, 863 to randomly the survey. selected Among U.S. optometrists, optometrists 36% and recom- convergence carried out simply by the subject holding a target 813 870 mendedophthalmologists pencil push-ups, were asked 22% what more treatment extensive they home-based would at arm’s length and then gradually bringing it toward the eye, all 814 Home-based computer vision therapy. The national 871 visionprescribe therapy, for a 16%motivated office-based teenage visionpatient therapy,with a classic 15% base- the time maintaining bifoveal fixation. These exercises should 815 besurvey carried106 outof treatmentseveral times patterns each day for for CI describeda few minutes.’’ above108 indi- The 872 insymptomatic prism glasses, CI who and 3%was nowilling treatment. to do whatever Among was ophthalmol- 816 necessary to eliminate his symptoms.106 Fifty-eight percent usecated of a that background about 24% target of to ophthalmologists provide feedback and regarding almost 36% 873 ogists, 50% recommended pencil push-up therapy, 21% 817 of the optometrists and 23% of the ophthalmologists physiologicof optometrists diplopia fairly appreciation often, often,is often or recommended always recommend to 874 extensive home-based vision therapy, 5% vision therapy, control for suppression.18,106,109,110 818 responded to the survey. Among optometrists, 36% recom- home-based therapy that is more intensive than standard 875 28%mended base-in pencil prism push-ups, glasses, 22% more and 8%extensive no treatment. home-based These 819 pencil push-ups. In the survey, home-based vision therapy 876 surveysvision therapy, underscore 16% office-based the lack of vision consensus therapy, among 15% base-in eye care Home-based computer vision therapy. The national 820 was described106 as the use of prisms, stereoscopes, or other 877 professionalsprism glasses, regardingand 3% no thetreatment. most appropriate Among ophthalmologists, treatment for survey of treatment patterns for CI described above indi- 821 catedhome-based that about device. 24% of Theophthalmologists use of computer and almost technology 36% of in 878 CI.50%Figure recommended 3 summarizes pencil push-up the prescribing therapy, 21% patterns extensive for both 822 home-based vision therapy, 5% vision therapy, 28% base-in prism optometristsvision therapy fairly became often, often, a reality or always in the recommend 1980s and home- has be- 879 optometrists and ophthalmologists.106 Similar treatment 823 glasses, and 8% no treatment. These surveys underscore the basedcome therapy a more that important is more intensive part of visionthan standard therapy pencil in the push- past 880 patterns were reported by India ophthalmologists, with ups. In the survey, home-based vision therapy was described as 824 lack of consensus among eye care professionals regarding the 10 years.111,112 881 79%most prescribing appropriate penciltreatment push-ups for CI. andFigure 18% 3 summarizes recommending the the use of prisms, stereoscopes, or other home-based devices. 825 Traditional home vision therapy, besides including pen- 882 synoptophoreprescribing patterns treatment. for both107 optometrists and The use of computer technology in vision therapy became a 826 106 cil push-ups, has included a host of other devices and 883 ophthalmologists.Three different ‘‘active’’ Similar treatment convergence patterns treatments were reported are reality in the 1980s and has become a more important part of 827 visiontechniques therapy to in improve the past PFC.10 years. In111,112 most of the techniques, the 884 commonlyby ophthalmologists prescribed in India, for patientswith 79% with prescribing symptomatic pencil push- CI: 828 ups and 18% recommending synoptophore treatment.107 demands of the patient are similar, however, with stimuli 885 1) home-based pencil push-up therapy, 2) home-based 829 Traditionalpresented home in a different vision therapy, way tobesides improve including PFC andpencil voluntary push- 886 therapy using prisms, computer programs such as Home ups, has included a host of other devices and techniques to 830 Three different ‘‘active’’ convergence treatments are commonly convergence amplitudes. These devices include loose 887 Q8 Therapyprescribed System for patients (HTS withÔ), stereoscopes,symptomatic CI: or 1) free-space home-based fu- improve PFC. In most of the techniques, the demands of the 831 ½ Š prisms, Brock string, stereoscopes with various targets, 888 sionpencil cards, push-up and therapy, 3) office-based 2) home-based vision therapy therapy. using3,106 prisms,Pencil patient are similar, however, with stimuli presented in a different 832 anaglyphs, and cheiroscopic cards designed to eliminate 889 push-ups,computer theprograms most such commonly as Home prescribed Therapy System treatment, (HTS™), are way to improve PFC and voluntary convergence amplitudes. 833 Thesesuppression devices include and improve loose prisms, PFC. Brock They string, are prescribedstereoscopes for 890 performedstereoscopes, at home or free-space with no fusion specialized cards, equipmentand 3) office-based and little 834 vision therapy.3,106 Pencil push-ups, the most commonly withhome various use and targets, monitored anaglyphs, in and the cheiroscopic office. cards designed 891 or no follow-up. Office-based vision therapy, on the other 835 prescribed treatment, are performed at home with no to eliminateThere are suppression several and disadvantages improve PFC. of They traditional are prescribed home- 892 hand, involves repeated office visits and therefore is more for home use and monitored in the office. 836 specialized equipment and little or no follow-up. Office-based based vision therapy including: 893 costlyvision andtherapy, time on intensive. the other hand, involves repeated office visits 837 894 and therefore is more costly and time intensive. 838 1. Traditional techniques often require an experienced 895 839 Treatment options doctor/technician to interpret the patient’s responses 896 840 and to use that information to alter stimulus condi- 897 841 Home-based pencil push-ups. The basic pencil push-up tions to improve binocular response. 898 842 technique typically prescribed, as described by Duke-Elder 2. Some children may not respond properly using tradi- 899 843 years ago, is comprised of ‘‘exercises to improve the near tional techniques, e.g., the child may ‘‘learn’’ the 900

FLA 5.1.0 DTD Š OPTM1143_proof Š 3 December 2011 Š 1:30 pm There are several disadvantages of traditional home- fixation disparity the greater the chance of having symptoms). based vision therapy including: From the foregoing, one would assume that prismatic correction, using Sheard’s criterion or correcting the angular 1. Traditional techniques often require an experienced fixation method, should eliminate asthenopia. However, doctor/technician to interpret the patient’s responses Saladin114 points out that there are 3 reasons that prismatic and to use that information to alter stimulus condi- correction satisfying Sheard’s criterion, or correcting the tions to improve binocular response. angular fixation, might not work: 1) the amount of prism 2. Some children may not respond properly using tradi- prescribed is relatively small in relationship to the phoria, 2) one tional techniques, e.g., the child may ‘‘learn’’ the would have to prescribe enough prism to flatten the fixation expected response and has a strong desire to please disparity curve to obtain any effect, and 3) slow adaptive the therapist; thus, the child may ‘‘give the right re- vergence would eventually compensate for the prism. sponse’’ even though not achieving the desired objective. Surgery. Bilateral medial resection has been advocated for 3. For learning to occur, feedback should be accurate, orthoptically nonresponsive symptomatic CI.115 immediate, consistent, and unbiased. Feedback, using traditional therapy techniques, must be provided by Effectiveness of treatment options the parent at home. Given human nature, the feed- back may not always be as consistent or as immediate Until recently, the literature on the effectiveness of various as required. treatments for CI included mostly case studies, case series, retrospective record reviews, and uncontrolled studies. Computerized home-based vision therapy overcomes these 3 potential problems and offers 4 additional advantages. Since 2005, however, the Convergence Insufficiency Treatment Trial Investigator group completed 4 randomized clinical trials 1. The use of home-based computer software allows for investigating the effectiveness of treatments for symptomatic CI standardization of therapy procedures. in children and adults (see Appendix 2). These included the 2. Because the computer software tracks the amount of CITT child pilot study, the adult pilot study, the base-in prism time spent doing the procedure and individual’s per- reading glasses study, and large-scale CITT clinical trial. In this formance, it provides a measure of adherence. section we review some of the older literature that used lower- 3. Computerized vision therapy uses principles of oper- quality experimental designs but emphasize the results from ant conditioning by providing immediate feedback prospective, well-designed studies. regarding correct and incorrect responses. 4. It creates progress graphs for short-term feedback at Home-based pencil push-ups effectiveness: research the end of the session and long-term feedback over evidence. Despite its popularity, there is minimal scientific time. evidence that pencil push-up treatment is an effective treatment for symptomatic CI. In a prospective, unmasked study Office-based vision therapy. Office-based vision therapy investigating pencil push-up treatment, 25 patients between 9 requires a patient to undergo a specific therapy regimen with and 51 years of age (mean age 25 years) with symptomatic CI regular office visits (e.g., once or twice per week). Typically, the were instructed to perform pencil push-ups at home, for 15 therapy is administered by a therapist (OD, MD, orthoptist, or minutes for 5 days a week, to track their performance using a specially trained technician) in the office and supplemented with daily log and return for follow-up in 6 weeks.116 Loss to follow- various home therapy procedures that are prescribed to be up was significant (13 of 25). Of the 12 patients who returned performed at home 5 to 7 days per week. The estimated time for their 6-week follow-up visits, only 7 (58%) of the patients of treatment for a person with CI is typically 10 to 20 office performing pencil push-ups showed a clinically significant visits.109,113 improvement in near point of convergence and positive fusional vergence (PFV) as defined by the blur when present and the Base-in prism reading glasses. Prisms are a simple break when the blur was not present. Nine of the 12 were method of decreasing the vergence demand created by the classified as definite CI and 3 classified as suspect CI. Of the exophoria. Their use has been limited in the management of definite CI subjects, 3 showed improvement in NPC and PFV CI.106 One of the reasons might be the concern eye care that allowed them to be classified as normal, 3 improved from providers have about prism adaptation (‘‘eating up prism: definite CI to suspect CI, and 3 remained definite CI. Of a phenomenon whereby the exophoria increases secondary the 3 suspect CI subjects, 1 improved to normal, and 2 to wearing compensatory prism).45 Another potential problem remained CI suspects. Thirty-three percent of those who re- with prism is that the amount of prism prescribed for near may turned for re-evaluation improved enough to be reclassified be inappropriate for distance, necessitating the prescription of 2 as normal, and 11 of 12 reported improvement in symptoms. pairs of glasses. It has been postulated that patients who do not demonstrate adaptation to prism, or have reduced slow In the CITT Child Pilot Study,117 47 children age 9 to 18 adaptive vergence, may be more likely to benefit from prism.46 years with symptomatic classical CI (demonstrated receded NPC, exophoria at near, and reduced PFC) were assigned Sheedy and Saladin38,63 reported that Sheard’s criterion did an randomly to receive a 12-week program of home-based excellent job of differentiating symptomatic exophores from pencil push-ups, office-based vision therapy, or office-based asymptomatic exophores. However, if Sheard’s criterion failed to placebo therapy. Eighty-eight percent of the subjects completed identify symptomatic exophoria, then Sheedy and Saladin the 12-week outcome examination. At the 12-week outcome reported that the angular amount of fixation disparity measured examination for the group assigned to home-based pencil push- should be used (according to Sheedy and Saladin the larger the ups, the CISS symptom score showed neither a statistical nor 10 Optometry, Vol -, No -, - 2012

1014 NPC, exophoria at near, and reduced PFC) were assigned 1071 1015 randomly to receive a 12-week program of home-based 1072 1016 pencil push-ups, office-based vision therapy, or office- 1073 1017 based placebo therapy. Eighty-eight percent of the subjects 1074

1018 completed the 12-week outcome examination. At the FPO 1075 1019 12-week outcome examination for the group assigned to = 1076 1020 home-based pencil push-ups, the CISS symptom score 1077 1021 showed neither a statistical nor clinically significant change 1078 1022 (mean 6 SD, 29.3 6 5.4 to 25.9 6 7.3; P 5 0.24) after the 1079 1023 12-week treatment. Clinically significant ‘‘improvement’’ 1080 1024 in the CISS was defined as a reduction of at least 10 points, print &1081 web 4C Figure 4 Reduction of symptoms by treatment procedure in children. 1025 however, with a final score of greater than 16 on the CISS, Treatment modalities for CI were combined and compared in 5 stud- 1082 1026 whereas a ‘‘cure’’ was defined as a reduction of 10 points ies.117,118,123,138 In-office vision therapy provides the highest percentage 1083 117 1027 and a score of less than 16. For the home-based pencil of patients in 4 studies to achieve asymptomatic scores (16 or less) on 1084 1028 push-ups group, the NPC improved minimally (mean 6 the CISS. 1085 1029 SD, 14.6 6 7.4 cm to 9.1 6 5.1 cm; P 5 0.08), and the 1086 1030 PFV at near showed no statistical improvement (mean 6 were resolved. There was a statistically significant im- 1087 1031 SD, 12.6 6 3.2 to 14.5 6 5.3; P 5 0.22). Pencil push-up provement in the mean near point of convergence break 1088 1032 therapy was found to be no more effective than the placebo measurement in the pencil push-ups group (12.5 cm 6 1089 1033 therapy. 6.6 to 7.8 cm 6 4.1, P , 0.001), although the changes 1090 1034 In the CITT, large-scale, randomized, clinical trial, 221 are not considered clinically significant. Only 46.7% (7 of 1091 1035 children age 9 to 17 years with symptomatic CI were 15) of subjects in the pencil push-ups group achieved a nor- 1092 1036 assigned randomly to receive a 12-week program of home- mal near point of convergence break measurement of ,6 1093 1037 based pencil push-ups, home-based computer vision ther- cm at the end of treatment (see Figure 5). 1094 1038 apy and pencil push-ups, office-based vision therapy with It is easy to understand the clinical popularity of the 1095 1039 home reinforcement, and office-based placebo therapy.81 pencil push-ups technique because of its simplicity and low 1096 1040 There was no statistically or clinically significant improve- cost. Standard, home-based pencil push-ups therapy can be 1097 1041 ment in symptoms for the home-based pencil push-ups easily taught to patients and prescribed in a very short time. 1098 1042 clinicallygroup. Althoughsignificant change symptoms (mean did ± SD, improve 29.3 ± 5.4 somewhat, to 25.9 ± the 12-weekIt also program requires of no the or same few follow-uptreatments visitsdescribed and noabove special- in 1099 7.3; P = 0.24) after the 12-week treatment. Clinically significant the Child Pilot Study.118 Eighty percent of the subjects 1043 ‘‘improvement’’change was no in more the CISS than was that defined foundin asthe a reduction placebo therapyof at completedized equipment. the 12-week Therefore, outcome it isexamination. significantly Patients less expensive in the 1100 1044 leastgroup 10 in points, achieving however, a normal with a or final improved score of symptom greater than score 16 on on penciland timepush-ups consuming group showed for patients. a decrease Nevertheless, in mean symptom there is no 1101 1045 thethe CISS, CISS. whereas a ‘‘cure’’ was defined as a reduction of 10 scorescientific (37.6 ± evidence 7.7 to 26.5 that ± 7.3), pencil although push-up this change therapy was is not more as 1102 1046 pointsAlthough and a score the posttreatmentof less than 16. NPC117 For for the the home-based pencil push-up largeeffective as that than observed placebo in the therapy vision fortherapy the group treatment and did of symp-not 1103 1047 pencilgroup push-ups was statistically group, the better NPC than improved that of minimally the placebo (mean group, ± reachtomatic the level convergence at which one insufficiency. would conclude that their 1104 1048 SD,the 14.6 change ± 7.4 was cm to not 9.1 clinically ± 5.1 cm; P significant. = 0.08), and Only the 40% of symptoms were resolved. There was a statistically significant 1105 PFV at near showed no statistical improvement (mean ± improvement in the mean near point of convergence break patients achieved a clinically normal NPC in the home- 1049 SD, 12.6 ± 3.2 to 14.5 ± 5.3; P = 0.22). Pencil push-up therapy measurementHome-based in the computer pencil push-ups vision group therapy: (12.5 cm ± research6.6 to 1106 1050 wasbased found pencil to be push-ups no more group.effective Therethan the was placebo no statistically therapy. 7.8evidence. cm ± 4.1, InP < a 0.001), well-designed although the prospective changes are study, not Cooper 1107 119 1051 significant difference in PFV between the home-based consideredand Feldman clinicallyused significant. computer-based Only 46.7% vision(7 of 15) therapy of subjects in an 1108 1052 Inpencil the CITT, push-ups large-scale, group randomized, and the placebo clinical group. trial, 221 children inoperant the pencil conditioning push-ups group paradigm achieved with a normal 8 subjects near to point determine of 1109 1053 age In9 to the 17 CITT years study,with symptomatic patients were CI classifiedwere assigned as ‘‘success- randomly convergenceif vergence break therapy measurement improved of vergence <6 cm at amplitudes.the end of They 1110 1054 toful’’ receive or ‘‘improved’’ a 12-week program using a of composite home-based outcome pencil classifica-push-ups, treatmentused an (see A–B Figure reversal 5). design. The experimental group (A) 1111 1055 home-basedtion. This composite computer outcomevision therapy classification and pencil considered push-ups, the 1112 office-based vision therapy with home reinforcement, and 1056 office-basedchange in allplacebo 3 outcome therapy.81 measures There was from no statistically baseline to or the 1113 1057 clinicallyoutcome significant examination. improvement Only 45% in symptoms of patients for in the the home- home- 1114 1058 based pencil pencil push-ups push-ups group. group Although were eithersymptoms ‘‘successful’’ did improve or 1115 1059 somewhat,‘‘improved.’’ the Thischange outcome was no wasmore no than better that thanfound that in the of the 1116 1060 placebo therapy therapy group (see inFigure achieving 4). a normal or improved 1117 symptom score on the CISS. 10 1061 Finally, in the CITT AdultOptometry, Pilot VolStudy,-, 46 No young-, - adults2012 1118

1062 19 to 30 years with symptomatic CI were assigned FPO 1119 = NPC, exophoria at near, and reduced PFC) were assigned1063 randomly to receive a 12-week program of the same 1120 1014 118 1071 1015 randomly to receive a 12-week program of home-based1064 treatments described above in the Child Pilot Study. 1072 1121 1016 pencil push-ups, office-based vision therapy, or office-1065 Eighty percent of the subjects completed the 12-week out- 1073 1122 1017 based placebo therapy. Eighty-eight percent of the subjects1066 come examination. Patients in the pencil push-ups group 1074 1123 1067 showed a decrease in mean symptom score (37.6 6 7.7 1124

1018 completed the 12-week outcome examination. At the FPO 1075 print & web 4C to 26.5 7.3), although this change was not as large as = 1019 12-week outcome examination for the group assigned1068 to 6 Figure1076Figure 5 Reduction 5 Reduction of symptoms of symptoms by treatment by treatment procedure procedure in adults. in adults. 1125 1020 home-based pencil push-ups, the CISS symptom score1069 that observed in the vision therapy group and did not reach Summary1077Summary findings findings of of treatment treatment as as derived derived from from the the pilot pilot adult adult study study for 1126 1021 showed neither a statistical nor clinically significant change1070 the level at which one would conclude that their symptoms for1078treatment treatment of of CIs CIs and and the the validation validation study. study.118118 1127 1022 (mean 6 SD, 29.3 6 5.4 to 25.9 6 7.3; P 5 0.24) after the 1079 It is easy to understand the clinical popularity of the pencil 1023 12-week treatment. Clinically significant ‘‘improvement’’ FLA 5.1.0 DTD Š OPTM1143_proof1080Š 3 December 2011 Š 1:30 pm print &push-ups web 4C technique because of its simplicity and low cost. 1024 in the CISS was defined as a reduction of at least 10 points, 1081 Figure 4 Reduction of symptoms by treatment procedure in children. Standard, home-based pencil push-ups therapy can be easily 1025 however, with a final score of greater than 16 on the CISS, Treatment modalities for CI were combined and compared in 5 stud- taught1082 to patients and prescribed in a very short time. It also 1026 whereas a ‘‘cure’’ was defined as a reduction of 10 points Figureies.117,118,123,138 4 ReductionIn-office of symptoms vision therapy by treatment provides procedure the highest in percentage children. requires1083 no or few follow-up visits and no specialized 117 1027 and a score of less than 16. For the home-based pencil Treatmentof patients modalities in 4 studies for CI to achievewere combined asymptomatic and compared scores (16 in or 5 less)studies. on equipment.1084 Therefore, it is significantly less expensive and time 1028 push-ups group, the NPC improved minimally (mean 6 117,the 118, CISS. 123, 138 In-office vision therapy provides the highest percentage of consuming1085 for patients. Nevertheless, there is no scientific 1029 SD, 14.6 6 7.4 cm to 9.1 6 5.1 cm; P 5 0.08), and the patients in 4 studies to achieve asymptomatic scores (16 or less) on the evidence1086 that pencil push-up therapy is more effective than CISS. 1030 PFV at near showed no statistical improvement (mean 6 were resolved. There was a statistically significant im- placebo1087 therapy for the treatment of symptomatic convergence 1031 SD, 12.6 6 3.2 to 14.5 6 5.3; P 5 0.22). Pencil push-up provement in the mean near point of convergence break insufficiency.1088 1032 therapy was found to be no more effective than the placebo measurement in the pencil push-ups group (12.5 cm 6 Home-based1089 computer vision therapy: research 1033 therapy. Although6.6 to 7.8the cmpost6 treatment4.1, P ,NPC0.001), for the although pencil push-up the changes 1090 group was statistically better than that of the placebo group, evidence. In a well-designed prospective study, Cooper and 1034 In the CITT, large-scale, randomized, clinical trial, 221 are not considered clinically significant. Only 46.7% (7 of 1091 119 the change was not clinically significant. Only 40% of patients Feldman used computer-based vision therapy in an operant 1035 children age 9 to 17 years with symptomatic CI were achieved15) of subjectsa clinically in normal the pencil NPC push-ups in the home-based group achieved pencil a nor- conditioning1092 paradigm with 8 subjects to determine if vergence 1036 assigned randomly to receive a 12-week program of home- push-upsmal near group. point There of convergence was no statistically break significant measurement difference of , 6 therapy1093 improved vergence amplitudes. They used an A–B 1037 based pencil push-ups, home-based computer vision ther- incm PFV at between the end the of treatmenthome-based (s eepencilFigure push-ups 5). group and the reversal1094 design. The experimental group (A) received vergence 1038 apy and pencil push-ups, office-based vision therapy with placeboIt isgroup. easy to understand the clinical popularity of the therapy,1095 and the control group (B) did not. (Eventually, the control group became the experimental group, and the 1039 home reinforcement, and office-based placebo therapy.81 pencil push-ups technique because of its simplicity and low 1096 In the CITT study, patients were classified as ‘‘successful’’ or experimental group became the control group). During 1040 There was no statistically or clinically significant improve- cost. Standard, home-based pencil push-ups therapy can be vergence1097 therapy, a correct response resulted in the computer 1041 ment in symptoms for the home-based pencil push-ups ‘‘improved’’easily taught using to a patients composite and outcome prescribed classification. in a very short Thistime. 1098 composite outcome classification considered the change in all 3 automatically and immediately giving the subject a positive 1042 group. Although symptoms did improve somewhat, the outcomeIt also requiresmeasures no from or fewbaseline follow-up to the outcome visits and examination. no special- auditory1099 reinforcement (beep) and an automatic increase in the 1043 change was no more than that found in the placebo therapy Onlyized 45% equipment. of patients Therefore, in the home-based it is significantly pencil push-ups less expensive group vergence1100 demand. Incorrect responses resulted in an audible 1044 group in achieving a normal or improved symptom score on wereand either time consuming‘‘successful’’ foror ‘‘improved.’’ patients. Nevertheless, This outcome there was is no no ‘‘boop’’1101 from the computer and a concurrent decrease in the 1045 the CISS. betterscientific than that evidence of the thatplacebo pencil therapy push-up (see Figure therapy 4). is more vergence1102 demand. Thus, the behavior of the subject controlled the vergence demand. Success was met with a harder demand, 1046 Although the posttreatment NPC for the pencil push-up effective than placebo therapy for the treatment of symp- 1103 Finally, in the CITT Adult Pilot Study, 46 young adults 19 to 30 failure, with an easier task. The control group received identical 1047 group was statistically better than that of the placebo group, tomatic convergence insufficiency. stimuli1104 and reinforcement; however, neither correct nor 1048 the change was not clinically significant. Only 40% of years with symptomatic CI were assigned randomly to receive a 1105 1049 patients achieved a clinically normal NPC in the home- Home-based computer vision therapy: research 1106 1050 based pencil push-ups group. There was no statistically evidence. In a well-designed prospective study, Cooper 1107 1051 significant difference in PFV between the home-based and Feldman119 used computer-based vision therapy in an 1108 1052 pencil push-ups group and the placebo group. operant conditioning paradigm with 8 subjects to determine 1109 1053 In the CITT study, patients were classified as ‘‘success- if vergence therapy improved vergence amplitudes. They 1110 1054 ful’’ or ‘‘improved’’ using a composite outcome classifica- used an A–B reversal design. The experimental group (A) 1111 1055 tion. This composite outcome classification considered the 1112 1056 change in all 3 outcome measures from baseline to the 1113 1057 outcome examination. Only 45% of patients in the home- 1114 1058 based pencil push-ups group were either ‘‘successful’’ or 1115 1059 ‘‘improved.’’ This outcome was no better than that of the 1116 1060 placebo therapy (see Figure 4). 1117 1061 Finally, in the CITT Adult Pilot Study, 46 young adults 1118

1062 19 to 30 years with symptomatic CI were assigned FPO 1119 1063 randomly to receive a 12-week program of the same = 1120 1064 treatments described above in the Child Pilot Study.118 1121 1065 Eighty percent of the subjects completed the 12-week out- 1122 1066 come examination. Patients in the pencil push-ups group 1123 1067 showed a decrease in mean symptom score (37.6 6 7.7 1124 to 26.5 7.3), although this change was not as large as print & web 4C 1068 6 Figure 5 Reduction of symptoms by treatment procedure in adults. 1125 1069 that observed in the vision therapy group and did not reach Summary findings of treatment as derived from the pilot adult study for 1126 1070 the level at which one would conclude that their symptoms treatment of CIs and the validation study.118 1127

FLA 5.1.0 DTD Š OPTM1143_proof Š 3 December 2011 Š 1:30 pm incorrect responses resulted in a change in the vergence Kertesz121 used computer-manipulated anaglyphs to demand. The results of this study showed that automated produce large vergence stimuli. He treated 29 patients with CI computerized therapy resulted in a rapid increase of fusional who had not responded to traditional orthoptic techniques. vergence. Concurrent transference of this ability to other Treatment included slowly separating large dichoptic targets in vergence tasks (e.g., vectogram vergence ranges) was also both convergence and divergence directions. Eighty percent of found. his sample improved PFC and decreased symptoms.

Daum et al.120 trained 6 subjects who received positive Thus, a number of small studies have indicated that vergence therapy using a slow vergence therapy rate (0.75Δ/s) computer-based vision therapy was effective in decreasing and 6 subjects who received positive vergence therapy using a symptoms and improving PFC in patients with convergence fast vergence therapy rate (5.00Δ/s). Six subjects served as anomalies.39,112,120,122 Many of the aforementioned studies controls and did not receive therapy. The therapy was used software similar to HTS, although administered in an performed using a computerized video display. The duration of office/research setting, and have provided a scientific basis for therapy was 80 minutes over a period of 4 weeks. All therapy its use in a clinical trial. activities were monitored. All vergence evaluations were double masked. Although both groups achieved substantial Until recently, however, there has been limited research of the increases in positive and negative vergence, there were greater effectiveness of computer-based therapy administrated entirely changes in the group with larger steps (5.00Δ/s) versus smaller at home. This type of therapy was studied for the first time in a phasic steps (0.75Δ/s). The authors concluded that vergence randomized, clinical trial in the large-scale CITT study.123 The therapy using a computerized video display was an effective results showed that there was no statistically or clinically technique for increasing PFC. significant improvement in symptoms for the home-based

Cooper et al.39 designed an experiment to determine if computer vision therapy group. Although symptoms did computer-based vision therapy was successful in treating improve somewhat, the change was no more than that found in convergence insufficiency and reducing symptoms. They again the placebo therapy group. Although the improvement in NPC used an A–B–A crossover design with 7 subjects to control for was significantly better than that of the placebo group, the experimental bias, placebo effects, and order effects. After the change was not clinically significant. The NPC after treatment in experimental phase, all patients exhibited statistically significant the home-based computer group was no better than that in the increases in maximum PFC compared with that recorded at home-based pencil push-ups group. Only 39% of patients baseline or the control phase. The mean increase in PFC for all achieved a clinically normal or improved NPC in the home- 7 patients was 17.7Δ (SD = 6.9Δ). In contrast, the PFC increase based computer vision therapy group. The improvement in the after the control phase was 2.4Δ (SD = 4.1Δ). Statistical analysis PFV was significantly better (higher) than in the home-based found that maximum PFC scores in baseline, control, and pencil push-ups and office-based placebo therapy groups but experimental phases were significantly different (F = 7.75; DF = significantly less than the improvement in the office-based vision 2, 12; P < 0.01). Also, there was a reduction in symptoms therapy group. Only 33% of patients in the home-based as measured on a scaled questionnaire given before and after computer vision therapy group were either ‘‘successful’’ or therapy. ‘‘improved.’’ This outcome was no better than that of the placebo therapy. Cooper and Jamal Literature Review 13

1356 completing therapy. In a retrospective study, Ciuffreda This composite outcome classification considered the 1413 1357 et al.133 reported a success rate of more than 90% in elim- change in all 3 outcome measurements from baseline to 1414 1358 inating signs and symptoms in patients with acquired ocu- the outcome examination. A ‘‘successful’’ outcome was a 1415 1359 lomotor dysfunction diagnosed secondary to acquired brain score of less than 16 on the CISS, a normal NPC (i.e., ,6 1416 D 1360 injury.Recently, The a majority retrospective of patients study of showed 43 prepresbyopic a form of patients conver- cm),Of historical and normal note, PFV many (i.e., of the.15 studiesand cited passing in Table Sheard’s 1 were cri- 1417 1361 gencewho insufficiency.completed the HTS was performed to determine the terion).performed ‘‘Improved’’ in the 1940s was in definedEngland asto aeliminate score of asthenopia less than and 16 1418 1362 effectivenessThe 3 CITT of studies home referredcomputerized to previously vision therapy were to the reduce first orimprove a 10-point productivity decrease during in the World CISS score,War II. and21,36,84,127 at least Most 1 of the 1419 1363 studiessymptoms that in used patients the with gold-standard, accommodative/vergence randomized clinicalanomalies. following:treatment normalprograms NPC, during improvement the war were in relatively NPC of moreshort than(5–11 1420 1364 trials124 The design initial to diagnosis investigate of the the patients efficacy was unknown, of office-based thus, the 4visits), cm, orand normal therapists PFV concentrated or an increase on building in PFV PFC, of more voluntary than 1421 1365 visionnumber therapy of patients in symptomatic exhibiting CI CIs.is unknown.117,118,123 BeforeThe and 2 pilot 10convergences,D. Patients who and didaccommodative not meet the convergences. criteria for ‘‘successful’’ Some 1422 immediately after treatment, all patients in this study filled out therapists used antisuppression techniques, whereas others 1366 studies117,118 and the large-scale CITT study123,134 showed or ‘‘improved’’ were considered ‘‘nonresponders.’’ 1423 the CISS. The initial symptoms score was 32.8 (SD = 8.1), and stressed jump vergence (disparity vergence).21,36,128,84 These 1367 thatafter office-based therapy the vision mean therapy symptom with score home decreased reinforcement to 20.6 (SD is = Althoughstudies included 73% ofnondocumented patients in thechanges office-based in signs and vergence/ 1424 1368 more11.5). effective These changes than either were both home-based clinically and pencil statistically push-ups, accommodativesymptoms associated therapy with group CI. For were example, either Stutterheim ‘‘successful’’129 and or 1425 1369 home-basedsignificant. computerForty percent vision were therapy, cured (score or office-based of 16 or less pla- and a ‘‘improved,’’Mann50 have suggested 45% of that patients visual inacuity the improved home-based as a function pencil 1426 1370 cebochange therapy of more for improvingthan 10 points both on thethe symptomsCISS) and 55% and improved signs push-upsof the elimination group, 33%of small of central the patients suppressions. in the Passmore home-based and 1427 13 1371 of(a CI. score of less than 16 or change of more than 10 points on computerMacLean vergence/accommodativenoted that general tension disappeared therapy group, and that and 1428 1372 theIn theCISS). large-scale In addition, CITT, average after convergence 12 weeks ofamplitude treatment, improved the 35%their of patients the office-based showed a positive placebo change group (35%)in personality. were similarly Others 1429 from 22Δ to 53Δ after treatment. Average divergence have reported that migraine headaches often cease at the end 1373 office-based vergence/accommodative therapy group’s classified (P , 0.002 for each comparison). There were no 1430 amplitudes improved from 15Δ to 25Δ. More than 75% of the of treatment of CI.13 1374 CISSpatients score finished (15.1) the was program significantly by 40 sessions lower than (equivalent the home- to 8 significant differences between the 2 home-based therapy 1431 1375 basedweeks). pencil These push-ups findings therapy, suggest that home-based use of the computer HTS system ver- groupsIn the past, and thethere placebo has been therapy a clinical group bias (againstP R 0.39 treating for both).older 1432 1376 gence/accommodativeresults in improved convergence therapy and and pencildivergence push-ups, amplitudes and patientsThese with results CI with showed vision thattherapy 12 on weeks the assumption of office-based that 1433 1377 office-basedwith a concomitant placebo reduction therapy groups’ in symptoms. scores There of 21.3, are clearly 24.7, vergence/accommodativethese patients were too old therapyfor therapy resulted to be successful. in a greater130 1434 131 1378 anddifferences 21.9, respectively between this ( Pstudy, and0.001 the CITT. for each The subjects’ compari- percentageHowever, Wick of patientset al. treated reaching 191 a presbyopic predetermined (aged 45–89 success 1435 years) patients with symptomatic CI with home-based 1379 son).prior123,134 diagnosticAlthough data symptomsand whether improved a CI was present somewhat were with criteria when compared with home-based pencil push-ups, 1436 unknown. Most of the patients did not reach the CISS criterion treatment, augmented by in-office treatment, for approximately 1380 thescore 2 home-based of 16 defined therapies,by the CITT these study treatmentsas asymptomatic. were no home-based10 weeks. He computer reported a vergence/accommodative93% cure rate with 48% needing therapy 1437 1381 moreAnother effective difference in improving in this study symptoms from the thanCITT office-basedstudy was the andadditional pencil treatment push-ups, after and 3 months office-based of follow-up. placebo Cohen therapy. and 1438 1382 placeborequirement therapy of (completionP . 0.38 of for the both program. comparisons). The authors After TheseSoden132 findings reported also a 96% show cure that rate in-office in 28 male vergence/accom- patients over the 1439 1383 treatment,suggested 73%that the of HTS patients system should assigned be used to on office-based those modativeage of 60 treated therapy for results approximately in a clinically 12 weeks. meaningful Eighty-three and 1440 1384 vergence/accommodativepatients with symptoms associated therapy achievedwith an accommodative/ a normal or statisticallypercent of their significantly patients maintained greater improvement their success in 9 symptomsto 12 1441 months after completing therapy. In a retrospective study, 1385 improvedvergence (10-point anomaly when or more in-office decrease) vision therapy symptom is not score practical. on and clinical measures of NPC and PFV for patients with CI. 1442 Ciuffreda et al.133 reported a success rate of more than 90% in 1386 the CISS, in contrast to 47% assigned to home-based pencil eliminatingFigures 6signs and and 7 depictsymptoms the in dynamic patients changeswith acquired of symp- ocu- 1443 In a retrospective study, 42 patients with symptomatic CI 26 1387 push-ups,were treated 39% assignedfor approximately to home-based 13 weeks computer using a home- vergence/ tomslomotor and dysfunction PFC over diagnosed time for secondary each treatment to acquired method. brain 1444 1388 accommodativebased orthoptic therapy program. and125 Of pencil the 42 push-ups, patients, 35 and were 43% Thereinjury. is The a majority significant of patients difference showed noted a form from of baselineconvergence by 1445 1389 assignedtreated towith office-based push-up exercises placebo and a therapy home-based (P 5computer0.006, theinsufficiency. fourth week. It is readily apparent that there is a general 1446 1390 0.0004,orthoptic and program, 0.0014, respectively).whereas the remaining 7 used only the 1447 1391 computerThe office-based orthoptic program. vergence/accommodative Before treatment the therapymean 1448 NPC was 24.2 cm. The posttreatment mean NPC improved 35 group showed a significantly improved NPC and PFV 1392 to 5.6 cm. Thirty-nine patients (92.8%) achieved an NPC of 1449 1393 comparedless than with 6 cm the (P other< 0.001); groups in addition, (P % 0.005).positive Althoughfusional the 30 1450 1394 meanvergence NPC improved of both home-basedin 39 patients groups(92.8%). measured Fourteen signifi-patients 1451 1395 cantlyhad a closer reduction than in the their office-based near exophoria placebo to less therapy than 5Δ group and 27 25 1452 1396 (pairwisepatients P(64.2%)values reported all %0.013), complete there resolution were no of significantsymptoms 1453 1397 differencesafter treatment. (P 5 The0.33) authors between reported the 2 that home-based home-based therapy 20 1454 computer orthoptic exercises reduced symptoms and improved 1398 groups. The mean posttreatment PFV for patients in the 15 1455

NPC and fusional amplitudes in symptomatic CI. They CI Symptom Survey score 1399 office-based vergence/accommodative therapy group was a 1456 concluded that the computer orthoptic program is an option HBPP

1400 significantly greater than all other groups (pairwise 10 FPO 1457 for treating symptomatic CI. The study had numerous design HBCVAT+ = 1401 P valuesflaws. The all ,authors0.001) did with not that use of a scaled the home-based questionnaire computer or a OBVAT 1458 5 1402 vergence/accommodativecontrol group, and the examiners therapy were and not pencil masked. push-ups Mean adjusted OBPT 1459 1403 group being significantly better (higher) than in the 1460 0 1404 home-basedOffice-based pencil vision push-ups therapy: (P 5 research0.037) and evidence. office-based Table 1 1461 lists studies from 1940 to 2002 that have reported on the Eligibility 4 week 8 week 12 week 1405 placebo therapy groups (P 5 0.008). The proportion3,126 of Study examination 1462 effectiveness of vision therapy for the treatment of CI. print & web 4C 1406 patientsThe total who number achieved of subjects a clinically in these normal studies levelis 2,182 for with both a Figure 6 Reduction of symptoms by treatment procedure in CITT. The 1463 1407 measures was 73% in the office-based vergence/accommo- mean CISS scores are depicted for the masked examinations at baseline, 1464 reported ‘‘cure’’ rate of 73.4% (range, 62%–96%). The Figure 6 Reduction of symptoms by treatment procedure in CITT. which were adjusted from the baseline at weeks 4, 8, and 12 for each 1408 dativecombined therapy ‘‘improved group versus and cure’’ no morerate is than92.4%, 40% although in each various of The mean CISS scores are depicted for the masked examinations at 1465 arm of therapy: in-office therapy with home supplemental therapy (OB- 1409 thedefinitions other 3 of treatmentcure were used. groups Most (P of, these0.001 studies, for however, each baseline which were adjusted from the baselne at weeks 4, 8, and 12 for 1466 have significant design flaws. Thus, the results, although VAT), office-based placebo therapy with home therapy (sham)(OBPT), 1410 comparison). home-basedeach arm of push-ups therapy: (HBPP), in-office and therapy home with computerized home supplemental vision therapy 1467 suggestive of effectiveness of office-based vision therapy, are not therapy (OB-VAT), office-based placebo therapy with home therapy 1411 conclusive.Finally, patients In today’s were era of classifiedevidence-based as ‘‘successful’’ health care, these or with pushups (HBCVAT1). (From Convergence Insufficiency Treat- 1468 1412 ‘‘improved’’ using a composite outcome classification. ment(sham)(OBPT), Trial Study home-based Group,123 withpushups permission.) (HBPP), and home computerized 1469 studies would not be considered adequate with regard to study vision therapy with pushups (HBCVAT+). (From Convergence methodology. Insufficiency Treatment Trial Study Group,123 with permission.) FLA 5.1.0 DTD Š OPTM1143_proof Š 3 December 2011 Š 1:30 pm The 3 CITT studies referred to previously were the first posttreatment PFV for patients in the office-based vergence/ studies that used the gold-standard, randomized clinical accommodative therapy group was significantly greater than all trials design to investigate the efficacy of office-based vision other groups (pairwise P values all ≤0.001) with that of the therapy in symptomatic CIs.117,118,123 The 2 pilot studies117,118 home-based computer vergence/accommodative therapy and and the large-scale CITT study123,134 showed that office-based pencil push-ups group being significantly better (higher) than in vision therapy with home reinforcement is more effective than the home-based pencil push-ups (P = 0.037) and office-based either home-based pencil push-ups, home-based computer placebo therapy groups (P = 0.008). The proportion of patients vision therapy, or office-based placebo therapy for improving who achieved a clinically normal level for both measures was both the symptoms and signs of CI. 73% in the office-based vergence/accommodative therapy group versus no more than 40% in each of the other 3 treatment In the large-scale CITT, after 12 weeks of treatment, the office- groups (P <0.001 for each comparison). based vergence/accommodative therapy group’s CISS score (15.1) was significantly lower than the home-based pencil push- Finally, patients were classified as ‘‘successful’’ or ‘‘improved’’ ups therapy, home-based computer vergence/accommodative using a composite outcome classification. This composite therapy and pencil push-ups, and office-based placebo therapy outcome classification considered the change in all 3 outcome groups’ scores of 21.3, 24.7, and 21.9, respectively (P < 0.001 for measurements from baseline to the outcome examination. A each comparison).123,134 Although symptoms improved ‘‘successful’’ outcome was a score of less than 16 on the CISS, a somewhat with the 2 home-based therapies, these treatments normal NPC (i.e., <6 cm), and normal PFV (i.e., .15Δ and passing were no more effective in improving symptoms than office- Sheard’s criterion). ‘‘Improved’’ was defined as a score of less based placebo therapy (P > 0.38 for both comparisons). After than 16 or a 10-point decrease in the CISS score, and at least 1 treatment, 73% of patients assigned to office-based of the following: normal NPC, improvement in NPC of more vergence/accommodative therapy achieved a normal or than 4 cm, or normal PFV or an increase in PFV of more than improved (10-point or more decrease) symptom score on 10Δ. Patients who did not meet the criteria for ‘‘successful’’ or the CISS, in contrast to 47% assigned to home-based pencil ‘‘improved’’ were considered ‘‘nonresponders.’’ Although 73% push-ups, 39% assigned to home-based computer vergence/ of patients in the office-based vergence/accommodative therapy accommodative therapy and pencil push-ups, and 43% group were either ‘‘successful’’ or ‘‘improved,’’ 45% of patients assigned to office-based placebo therapy (P = 0.006, 0.0004, and in the home-based pencil push-ups group, 33% of the patients in 0.0014, respectively). the home-based computer vergence/accommodative therapy 14 group, and 35% of the office-basedOptometry, placebo Vol group-, No (35%)-, were- 2012 similarly classified (P < 0.002 for each comparison). There were 1470 no significantStavis el differences al.137 prescribed between prism the 2 forhome-based 72 children therapy ages 8 to 1527 1471 groups18 years and the with placebo symptomatic therapy group exophoria. (P ≥ 0.39 They for reported both). a de- 1528 1472 crease in symptoms and a significant improvement in read- 1529 1473 Theseing results scores showed (speed, that accuracy, 12 weeks andof office-based comprehension) vergence/ on a 1530 accommodative therapy resulted in a greater percentage of 1474 patientsstandardized reaching Graya predetermined Oral Reading success Test. criteria There when were numer- 1531 1475 comparedous problems with home-based with the pencil study push-ups, design. home-based The questionnaire 1532 1476 computerwas not vergence/accommodative scaled, the questions appeartherapy toand be pencil biased, push- exam- 1533

1477 FPO ups,iners and office-based were not masked, placebo therapy. and there These was findings no control also show group. 1534 = 1478 thatThus, in-office the vergence/accommodative interpretation of the results therapy from results this in a study is 1535 clinically meaningful and statistically significantly greater 1479 open to question. It should be noted that none of the afore- 1536 improvement in symptoms and clinical measures of NPC and 1480 PFVmentioned for patients patients with CI. had classical CI; the diagnosis was 1537 1481 based on measurements of the deviation or Sheard’s 1538 1482 Figurescriterion. 6 and 7 depict the dynamic changes of symptoms and 1539 print & web 4C PFC over time for each treatment method.26 There is a 1483 Figure 7 Change in positive fusional vergence amplitudes during the In a prospective double-masked, multicenter, random- 1540 significant difference noted from baseline by the fourth week. It 1484 CITT.Figure The 7 positive Change fusional in positive vergence fusional amplitudes vergence (blur amplitudes if not presentduring the then ized clinical trial, 72 children 9 to less than 18 years of age 1541 is readily apparent that there is a general decrease in symptoms theCITT. break The point), positive from fusional baseline, vergence are depicted amplitudes for the (blur masked if not examinations present 1485 overwith time symptomatic in all 4 groups, CI but were with assigneda more rapid randomly decrease to in base-in 1542 1486 atthen baseline, the break which point), were from adjusted baseline, at4 are weeks, depicted 8 weeks, for the and masked 12 weeks of prism glasses (distance optical prescription plus prism 1543 treatmentexaminations for eachat baseline, arm, in-office which were therapy adjusted (OBVAT), at 4 weeks, office-based 8 weeks, placebo and symptoms in the office-based group with supplemental home 1487 therapyamount compared based onwith Sheard’s the other criterion) treatments. or The placebo mean positive (distance 1544 therapy12 weeks with of treatment home therapy for each (sham)(OBPT), arm, in-office home-based therapy (OBVAT), push-ups (HBPP), office- 138 1488 andbased home placebo computerized therapy with vision home therapy therapy with (sham)(OBPT), pushups (HBCVAT home-based1). (From fusionaloptical amplitude prescription for patients and no in prism)the office-based reading and glasses. home- Pa- 1545 123 1489 Convergencepush-ups (HBPP), Insufficiency and home computerized Treatment Trial vision Study therapy Group, with pushupswith basedtients computer were instructed groups began to wear to diverge the glasses from the for other all near groups tasks 1546 by week 4. In all cases, positive fusional amplitudes improved 1490 permission.)(HBCVAT+). (From Convergence Insufficiency Treatment Trial Study of more than 5 minutes duration. Symptoms were measured 1547 Group,123 with permission.) before improvement in symptoms. As the duration of therapy 1491 increased,using the so CISSdid the that percentage was given of patients at the baselinebeing classified examination 1548 1492 decrease in symptoms over time in all 4 groups, but with a as and‘‘successful’’ after 6 or weeks ‘‘improved’’: of glasses 4 weeks wear. (34%), The 8 meanweeks CISS score 1549 1493 moreThe office-based rapid decrease vergence/accommodative in symptoms in the therapy office-based group group (45%),decreased and 12 equallyweeks (73%). (i.e.,26 less Thesymptomatic) slopes of the symptoms in both groups.and 1550 1494 withshowed supplemental a significantly home improved therapy NPC compared and PFV compared with the with other fusionalPatients amplitude wearing graphs base-in suggest prism that glasses if therapy at theis not initial exami- 1551 1495 treatments.the other groups The (P mean ≤ 0.005). positive Although fusional the amplitudemean NPC forof both pa- successfulnation hadat the an 12-week initial mark, asthenopia therapy scoreshould ofcontinue 31.6 (610.4), 1552 for at least another 4 weeks. 1496 tientshome-based in the groups office-based measured and significantly home-based closer computer than the groups which became 16.5 (69.2) after 6 weeks of wearing pris- 1553 office-based placebo therapy group (pairwise P values all 1497 began to diverge from the other groups by week 4. In all matic glasses. Those wearing the placebo glasses had a 1554 ≤0.013), there were no significant differences (P = 0.33) 1498 cases,between positive the 2 home-based fusional amplitudes therapy groups. improved The mean before im- mean score of 28.4 (68.8) before wearing glasses and 1555 1499 provement in symptoms. As the duration of therapy in- 17.5 (612.3) after wearing nonprismatic glasses. In chil- 1556 1500 creased, so did the percentage of patients being classified dren 9 to less than 18 years of age with symptomatic CI, 1557 1501 as ‘‘successful’’ or ‘‘improved’’: 4 weeks (34%), 8 weeks base-in prism reading glasses were found to be no more ef- 1558 1502 (45%), and 12 weeks (73%).26 The slopes of the symptoms fective in alleviating symptoms or improving clinical find- 1559 1503 and fusional amplitude graphs suggest that if therapy is not ings than the placebo effect of prescribing any eyeglasses 1560 1504 successful at the 12-week mark, therapy should continue for this age group. 1561 1505 for at least another 4 weeks. Dusek et al.139 recently reported on 134 patients with CI 1562 1506 (aged 7–14 years) and with reading difficulties who were 1563 1507 Base-in reading glasses. There are only a few studies either prescribed 8D base-in reading spectacles (N 5 51) 1564 1508 evaluating the efficacy of prescribing prisms to decrease the or computerized home vision therapy (N 5 51). Thirty- 1565 1509 symptoms associated with any binocular anomaly including two participants refused all treatment and were designated 1566 1510 convergence insufficiency. Worrell et al.135 prescribed 2 the control group. Reading speed and accuracy were mea- 1567 1511 pairs of glasses to a group of patients who had failed sured before and after treatment using The Salzburg Read- 1568 1512 Sheard’s criterion61 (i.e., positive fusional vergence finding ing Test for all 3 treatment arms. In this section, we report 1569 1513 less than twice the magnitude of the ocular deviation); only on those that were prescribed prism. Mean reading er- 1570 1514 1 group was prescribed prism to satisfy Sheard’s criterion, ror scores for the control group were initially 5.34 6 3.5 1571 1515 and a second group was prescribed a pair of glasses without and posttherapy 4.66 6 2.9 with a difference of 0.69 6 1572 1516 prism. They found that the application of prism to meet 1.20, which was not significant, while the prism group ini- 1573 1517 Sheard’s criterion was not predictably successful for pa- tially had a score of 4.92 6 4.06 and a posttherapy score of 1574 1518 tients demonstrating exophoria at near (11 of 24 preferred 2.12 6 1.9 with a difference of 2.80 6 2.82, which was sig- 1575 1519 the prism). They noted that better results were achieved nificant. Mean total reading time in seconds for the control 1576 1520 in the presbyopic population. Their sample was too small group was initially 130.88 6 61.46, and posttherapy mean 1577 1521 to draw statistical conclusions. score was 127.03 6 60.59 with a difference of 3.84 6 4.04, 1578 Q11 114,136 1522 ½ Š In an unpublished study by Roy and Saladin, sub- which was not significant; while the prism group initially 1579 1523 jects performed a reading task before and after wearing had a mean score of 108.49 6 48.68, and a posttherapy 1580 1524 prisms. They stated that the prisms did not improve the score of 87.00 6 39.60 with a difference of 21.49 6 1581 1525 symptoms. Saladin concluded that only vision therapy 13.53, which was significant. Durek et al.139 concluded 1582 1526 will be corrective for asthenopic symptoms. that the wearing of prisms at near improved both speed 1583

FLA 5.1.0 DTD Š OPTM1143_proof Š 3 December 2011 Š 1:30 pm Base-in reading glasses. There are only a few studies 2.9 with a difference of 0.69 ±1.20, which was not significant, evaluating the efficacy of prescribing prisms to decrease the while the prism group initially had a score of 4.92 ± 4.06 and a symptoms associated with any binocular anomaly including posttherapy score of 2.12 ± 1.9 with a difference of 2.80 ± convergence insufficiency. Worrell et al.135 prescribed 2 pairs 2.82, which was significant. Mean total reading time in seconds of glasses to a group of patients who had failed Sheard’s for the control group was initially 130.88 ± 61.46, and criterion61 (i.e., positive fusional vergence finding less than twice posttherapy mean score was 127.03 ± 60.59 with a difference the magnitude of the ocular deviation); 1 group was prescribed of 3.84 ± 4.04, which was not significant; while the prism group prism to satisfy Sheard’s criterion, and a second group was initially had a mean score of 108.49 ± 48.68, and a posttherapy prescribed a pair of glasses without prism. They found that the score of 87.00 ± 39.60 with a difference of 21.49 ± 13.53, which application of prism to meet Sheard’s criterion was not was significant. Durek et al.139 concluded that the wearing of predictably successful for patients demonstrating exophoria at prisms at near improved both speed and accuracy of reading. near (11 of 24 preferred the prism). They noted that better However, it should be noted that the measurements were taken results were achieved in the presbyopic population. Their only a month after wearing the prism. Because prism results sample was too small to draw statistical conclusions. may be diminished over time because of adaptation, the authors need to present long-term evidence. In addition, the examiner In an unpublished study by Roy and Saladin,114,136 subjects was not masked. performed a reading task before and after wearing prisms. They stated that the prisms did not improve the symptoms. Saladin A prospective study of symptomatic CI subjects ages 45 to 68 concluded that only vision therapy will be corrective for years was performed.140 Each subject was assigned 2 pairs of asthenopic symptoms. progressive addition glasses, 1 with BI prism and 1 without prism. Subjects wore each pair of glasses for 3 weeks and then Stavis el al.137 prescribed prism for 72 children ages 8 to18 completed the CISS. The mean CISS score before wearing the years with symptomatic exophoria. They reported a decrease glasses was 30 and decreased to 13 with the BI-prism glasses in symptoms and a significant improvement in reading scores and 24 with glasses without prism. Progressive addition glasses (speed, accuracy, and comprehension) on a standardized Gray with BI prism were found to be effective in reducing symptoms Oral Reading Test. There were numerous problems with the of presbyopes with symptomatic CI, at least for the short term. study design. The questionnaire was not scaled, the questions appear to be biased, examiners were not masked, and there was Surgery. The surgical success rates for CI are variable. no control group. Thus, the interpretation of the results from The few studies evaluating surgical intervention used small this study is open to question. It should be noted that none of sample sizes, which were retrospective in design and the aforementioned patients had classical CI; the diagnosis was performed only on adults.141-144 Only 1 study provided any based on measurements of the deviation or Sheard’s long-term data that demonstrated a high percentage of criterion. regression.145 There is a paucity of information on surgery for children with CI, none meeting the rigor to exclude In a prospective double-masked, multicenter, random- experimental biases, placebo effects, and more.146 ized clinical trial, 72 children 9 to less than 18 years of age with symptomatic CI were assigned randomly to base-in prism Long-term results glasses (distance optical prescription plus prism amount based on Sheard’s criterion) or placebo (distance optical prescription There are 3 studies that have evaluated the long-term efficacy and no prism) reading glasses.138 Patients were instructed to of vision therapy/orthoptics for CI. Pantano147 reported on 207 wear the glasses for all near tasks of more than 5 minutes treated, symptomatic patients with CI (age 10–46 years) who duration. Symptoms were measured using the CISS that was were treated with home-based orthoptic exercises using a given at the baseline examination and after 6 weeks of glasses stereoscope. The most consistent objective findings before wear. The mean CISS score decreased equally (i.e., less treatment were a remote NPC and reduced distance symptomatic) in both groups. Patients wearing base-in prism convergence amplitudes. After treatment, the patients were glasses at the initial examination had an initial asthenopia score divided into 2 groups: those that were cured and developed of 31.6 (±10.4), which became 16.5 (69.2) after 6 weeks of voluntary convergence and those in whom voluntary wearing prismatic glasses. Those wearing the placebo glasses convergence did not development. The patients were had a mean score of 28.4 (±8.8) before wearing glasses and reexamined by Pantano at 6 months and 2 years post therapy. 17.5 (±12.3) after wearing nonprismatic glasses. In children 9 to Of the 104 who were cured, 100% were reported to remain less than 18 years of age with symptomatic CI, base-in prism symptom free after 2 years. The 103 patients who did not have reading glasses were found to be no more effective in alleviating voluntary convergence regressed, 21% reported symptoms at 6 symptoms or improving clinical findings than the placebo effect months, and 88% reported symptoms by 2 years after of prescribing any eyeglasses for this age group. treatment. This study did not have a control group, and the examiners at outcome were unmasked. Dusek et al.139 recently reported on 134 patients with CI (ages 7–14 years) and with reading difficulties who were Patients who were asymptomatic after a 12-week therapy either prescribed 8Δ base-in reading spectacles (N = 51) or program in the large-scale CITT were followed up with computerized home vision therapy (N = 51). Thirty-two for 1 year.123 Maintenance therapy was prescribed for the first participants refused all treatment and were designated the 6 months; followed by no treatment for the next 6 months. control group. Reading speed and accuracy were measured Symptoms and clinical signs were measured at the completion before and after treatment using The Salzburg Reading Test for of therapy, 6 months and 1 year after completion. The mean all 3 treatment arms. In this section, we report only on those change on the CISS, NPC, PFV, and the proportion of patients that were prescribed prism. Mean reading error scores for the who remained asymptomatic on the CISS or who were control group were initially 5.34 ± 3.5 and posttherapy 4.66 ± classified as successful or improved based on a composite measure of CISS, NPC, and PFV were measured. Improvements be used to discriminate between symptomatic and in symptoms and clinical signs occurring after 12 weeks of asymptomatic CI. They believe that symptomatic CI has poor therapy were maintained in most children ages 9 to 17 years for vergence adaptation, whereas asymptomatic CIs have normal at least 1 year after discontinuing treatment, i.e., there were no vergence adaptation. Normal vergence adaptation suggests significant differences in the CISS, NPC, or PFV (P values a robust slow adaptive vergence system that eliminates a ≥ 0.077). time-related demand on the fast disparity vergence system. (For a complete discussion of accommodative-vergence Shin et al.148 evaluated 57 children ages 9 to 13 years who modeling see Ciuffreda.151) Eight patients with symptomatic CI initially had symptomatic CI (N = 27) or symptomatic and ‘‘poor’’ slow adaptive vergence received 8 weeks of vision CI with an AI (N = 30). They were divided into 2 groups: a therapy. After therapy, vergence adaptation and fusional treatment and a control group. The treatment group received amplitudes were measured. Both findings were found to have 12 weeks of in-office VT, whereas the control group did not improved significantly with a concurrent reduction in receive any therapy. A quality-of-life survey was used to asthenopia. North and Henson45,90 postulated that improved measure symptoms in both groups. Twenty children in the vergence adaptation is the reason for elimination of asthenopia treatment group were re-examined 1 year after treatment. and the reason these patients achieve lasting results. Cooper et Symptom scores were significantly different after 12 weeks of al.39 showed that vision therapy resulted in flattening of the treatment in the treatment group (P < 0.001), whereas no fixation disparity curves with implied improvement in slow changes were noted in the control group. A 1-year follow-up adaptive vergence. examination found that most children maintained the improvement in symptoms and clinical measures after therapy. Thus, treatment of convergence insufficiency with vision therapy involves the normalization of convergence facility Objective outcome measures and amplitude, accommodative–vergence interactions, ac- commodative facility and amplitude, voluntary vergence, In a unique design, Grisham et al.149 used an infrared eye and development of improved vergence adaptation.3,152 Slow movement system to objectively measure vergence in a small adaptive vergence is necessary to maintain vergence over time sample of post orthoptic CI patients. In all other studies, and reduce the load on disparity–vergence (fast vergence) over investigators used subjective clinical measures, such as NPC and time.59 In the authors’ experience, treatment usually results in PFV. Grisham et al.149 measured eye movements before and an initial improvement in fusional amplitudes before symptoms after the administration of a variety of accommodative-vergence are eliminated. It is not until both accommodative and vergence therapeutic techniques. Before therapy, the subjects could only findings are automated that symptoms are permanently accurately track vergence stimuli that changed at a slow pace, eliminated. whereas after therapy, fusional movements were full and accurate to a variety of fusional stimuli. Subjects reevaluated 6 Vision therapy and its relationship to reading to 9 months after cessation of therapy did not show any evidence of regression. In addition, these patients reported There have been a few articles evaluating the effectiveness elimination of their symptoms. of convergence training for children who have reading difficulties. Atzmon et al.153 divided 62 second graders who Recently, neurologic correlates of both subjects with CI and had reading difficulties and presumed convergence defects, normal findings were quantified using functional magnetic based on an arbitrary definition of reduced convergence resonance imaging scans while performing random and amplitudes, into 2 groups: 1 group received reading tutoring predictable convergence and divergence fusional movements150 only, and the second group received orthoptics only. Each child a method by which eye movements are recorded objectively. received approximately 37 sessions of therapy over 2 to 3 All CI subjects had 18 hours of vision therapy. Subjects in the months. At the end of treatment, standardized reading tests study were evaluated at baseline, during therapy, 4 months after were given for both groups. Improvement in reading was vision therapy, and a year after vision therapy. Convergence and marked and equal in both groups, with the orthoptic group divergence average peak velocities to step stimuli before enjoying the additional benefit of alleviation of all asthenopic therapy were significantly slower in CI subjects compared with symptoms. Atzmon et al.153 concluded that orthoptic treatment controls. Peak velocities are the maximum velocity of the eyes is as effective as conventional reading tutoring and less that occur during a vergence response. The slower the peak expensive. velocity, the longer it takes the eyes to make a fusional response; it took patients with CI initially up to 2 seconds to Recently, Goss et al.154 studied a sample of fourth graders who fuse a target and 500 milliseconds for normals. After therapy, were randomly divided into 1 of 2 groups. One group received convergence average peak velocities became normal. The placebo therapy and the other group active therapy, i.e., ‘‘real amount of functional activity within the frontal areas, HTS,’’ a home therapy system designed to use operant cerebellum, and brain stem increased significantly after therapy conditioning to improve ocular motility, accommodation, and on functional magnetic resonance imaging. The NPC was vergence. Few subjects finished either arm of therapy; however, directly correlated to activity in the brain stem. This is the first for those who did complete therapy, the trend was that those study to demonstrate neurologic changes after vision therapy. patients who were in the “real HTS’’ group had a much larger improvement in reading scores. Goss et al.154 repeated the Underlying physiological changes in successful experiment without a control group in a group of third graders. vision therapy The group that used HTS improved their reading scores by 1.8 years compared with placebo and control groups that improved North and Henson45 suggested that vergence adaptation can by 0.9 years. Those that did not complete therapy did not perform any better than the placebo or the control groups. It is important to note that success was directly related to effective than therapy performed for the same amount of time compliance in therapy. in 1 day.157 A variety of stimuli should be used to stimulate amplitudes, facility, and sustaining ability. Lastly, to improve Dusek et al.139 as previously stated, reported on 134 patients reflexive accommodative/vergence responses, movement and with CI (ages 7–14 years) and reading difficulties, who were other confounding stimuli should be added to therapy. either prescribed 8Δ base-in reading spectacles (N = 51) or computerized home vision therapy (N = 51). Each phase should take approximately 6 visits when combined Thirty-two participants refused all treatment and were with home reinforcement therapy. Patients often notice designated the control group. Reading speed and accuracy were worsening of symptoms during the first few weeks of measured before and after treatment for all 3 groups. In this therapy. Rarely, they may even vomit from the exercises. section, we are reporting only on the HTS group (the prism Before therapy, the patient should be advised of the group was previously presented in the prism therapy section). possibility of these adverse effects. After this period of Mean reading error scores for the control group were initially increased discomfort, most patients begin to report that their 5.34 ± 3.5 and after therapy 4.66 ± 2.9 with a difference of 0.69 symptoms disappear, concentration increases, and near vision ± 1.20, which was not significant; the HTS group initially had a tasks are easier. We advocate the integration of score of .53 ± 3.06 and a posttherapy score of 2.86 ± 1.9 with a nonaccommodative/vergence tasks while doing therapy difference of 1.67 ± 1.90, which was significant. Mean total to improve automaticity. For example, have the patient perform reading time in seconds for the control group was initially a math task while altering vergence. The goal of therapy is to 130.88 ± 61.46, and posttherapy scores were 127.03 ± improve the automaticity of reflexive accommodative–vergence 60.59 with a difference of 3.84 ± 4.04, which was not movements. The successful results found with office-based significant; the HTS group initially had 113.98 ± 48.83 vision therapy may be related to the therapist interaction with and a posttherapy score 101.61 ± 37.53 with a difference the patient in developing reflexive accommodative–vergence. of 12.37 ± 16.22, which was significant. Durek et al.139 found Description of therapy techniques may be found elsewhere. that the HTS improved both speed and accuracy of reading in a 109,113,116 group of children with both a CI and reading problems compared with a control group. Previous studies have Summary suggested that the minimal number of HTS therapeutic sessions needed to be greater than 8 to remediate a vergence defect. CI patients have reduced convergence that manifests itself 26,124,125 One might wonder what the results would be had through reduced convergence fusional amplitudes and an there been a longer period of therapy, i.e., 1 month, especially increased effort associated with convergence, significant since the authors suggested that prism and HTS treatment yield exophoria at near, or receded near point of convergence. similar results. These patients usually manifest symptoms that may be detected with the CISS. The symptoms associated with accommodative– Current clinical guides for the treatment of vergence anomalies are unique and may be differentiated from symptomatic CI dry eye and other conditions. The intensity of symptoms in CI may be dependent on the amount and type of near work, Review of the literature currently supports a specific CITT degree of suppression, or sensitivity to pain. protocol for in-office vision therapy with supplemental home therapy.25,155,156 If office-based vision therapy is im- The NEI/NIH CITT clinical trials were designed to determine practical because of cost, time constraints, and other factors, the most effective treatment(s) for eliminating then home-based computer vision therapy using random symptoms associated with CI. The treatment arms included dot stereograms (RDS) in an operant conditioning paradigm and office-based accommodative–vergence therapy with sup- push-up techniques can be prescribed.25,156 The operant plemental home therapy, placebo office-based vision therapy, conditioning paradigm should be monitored on the Internet home-based computerized vision therapy with pencil with frequent office visits to foster compliance. In addition, it is push-ups, and pencil push-ups. At the end of 12 weeks of useful to supplement computer therapy with noncomputerized therapy, treatment effects were assessed. In-office accom- therapeutic techniques, such as pencil push-ups, Brock string, modative–vergence supplemented with home therapy was Lifesavers cards, stereoscopes, and loose prisms. Incorporation found to be the most effective treatment. Long-term effects of ‘‘distractors,’’ such as talking to the patient or having the were determined at 6 months and 12 months of follow-up patient move while doing therapy, may help to automate and found to persist for each therapeutic treatment arm. accommodative– vergence responses. When home-based If the CITT-defined gold standard of treatment is not computer vision therapy is prescribed, therapeutic results available, then it is our opinion that the patient should be should be evaluated every month to evaluate progress and to prescribed home-based computerized vision therapy with emphasize the importance of treatment. Utilization of the pencil push-ups.25,156 Home-based computer vision therapy symptoms questionnaire (CISS117,118) provides both the clinician should be performed with follow-up, including monthly visits and patient a scientifically validated method of monitoring and printouts of performance or internet tracking to improve symptoms before and after therapy. compliance. The clinician should incorporate a home training regimen that has some of the characteristics of office-based Therapy includes 3 phases:1) normalization of accommodative vision therapy, e.g., distractors. 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Ophthalmic Physiol Opt exodeviation after corneal refractive surgery for moderate to 1989;9(3): 264-8. high myopia. Ophthalm Surg Lasers Imaging 2003;34(5):363-70. 57. Schor CM. Models of mutual interactions between 83. Sheedy J, Saladin J. Phoria, exophoria at near in presbyopia. Am J accommodation and convergence. Am J Optom Physiol Optics Optom Physiol Opt 1975;52:474-81. 1985;62(6):369-74. 84. Duthie OM. Convergence deficiency. Br Orthoptic J 1944. 38-4 58. Hung GK, Semmlow JL, Ciuffreda KJ. A dual-mode dynamic 85. Manson N. Anaemia as an aetiological factor in convergence model of the vergence eye movement system. IEEE Transactions insufficiency. Br J Ophthalmol 1962;6:647-77. on Bio-medical Engineering 1986;33(11):1021-8. 86. Regula J, Rupinski M, Kraszewska E, et al. Colonoscopy in 59. Cooper J. Clinical implications of vergence adaptation. Optom colorectal-cancer screening for detection of advanced neoplasia. Vis Sci 1992;69(4):300-7. N Engl J Med 2006;355(18):1863-72. 60. Sethi B. Vergence adaptation: a review. Documenta 87. Jampolsky A. Ocular divergence mechanisms. Tr Am Ophthal Ophthalmologica 1986;63(3):247-63. Society 1971;68:730-822. 61. Sheard C. Zones of ocular comfort. American Journal of 88. Nawratzki I, Avrouskine M. Psychogenic factors in disturbances Optometry & Archives of American Academy of Optometry of ocular muscle balance; exophoria with convergence 1930;7:9-25. insufficiency. Acta Medica Orientalia 1957;16(3-4):94-6. 62. Neumueller JF. The correlation of binocular measurements for 89. Fink WH. Symposium: convergence insufficiency: refractive diagnosis. American Journal of Optometry and physiopathology. Am Orthoptic J 1953;3:5-12. Archives of American Academy of Optometry 1946;23(6). 90. North RV, Henson DB. The effect of orthoptic treatment upon 63. Sheedy JE, Saladin JJ. Phoria, vergence, and fixation disparity in the vergence adaptation mechanism. Optom Vis Sci 1992;69(4): oculomotor problems. American J Optom Physiol Optics 294-9. 1977;54(7): 474-8. 91. Chandler R. Some observations on orthoptic treatment 64. Prakash P, Agarwal L, Nag S. Accommodational weakness and following head injury. Br Orthoptic J 1944;2:56-62. convergence insufficiency. Orient Arch Ophthalmol 92. Krohel GB, Kristan RW, Simon JW, Barrows NA. Posttraumatic 1972;10:261-4. convergence insufficiency. Ann Ophthalmol 1986;18(3):101-2, 04. 65. Von Noorden GK, Brown DJ, Parks M. Associated convergence 93. Cohen M, Groswasser Z, Barchadski R, et al. Convergence and accommodative insufficiency. Documenta Ophthalmologica insufficiency in brain-injured patients. Brain Inj 1989;3(2):187-91. 1973; 34(1):393-403. 94. Kowal L. Ophthalmic manifestations of head injury. Aust NZ J 66. Bugola J. Hypoaccommodation and convergence insufficiency. Am Ophthalmol 1992;20(1):35-40. Orthoptic J 1977;27:85-90. 95. Lepore FE. Disorders of ocular motility following head trauma. 67. Raskind RH. Problems at the reading distance. American Arch Neurol 1995;52(9):924-6. Orthoptic J 1976;26:53-9. 96. Ciuffreda KJ, Kapoor N, Rutner D, Suchoff IB, Han ME, Craig S. 68. Marran LF, De Land PN, Nguyen AL. Accommodative Occurrence of oculomotor dysfunctions in acquired brain insufficiency is the primary source of symptoms in children injury: a retrospective analysis. Optometry 2007;78(4):155-61. diagnosed with convergence insufficiency. Optom Vis Sci 97. Brahm KD WH, Kirby J, Ingalla S, Chang C, Goodrich GL. Visual 2006;83(5):281-9. Impairment and dysfunction in combat-injured service members 69. Marran L, Deland P, Nguyen A. Accommodative insufficiency is with traumatic brain injury. Optom Vis Sci 2009;86(7):817-25. the primary source of symptoms in children diagnosed with 98. Goodrich GL, Kirby J, Cockerham G, Ingalla SP, Lew HL. Visual convergence insufficiency: authors’ response. Optom Vis Sci function in patients of a polytrauma rehabilitation center: A 2006;83(11):858-9. descriptive study. J Rehabil Res Dev 2007;44(7):929-36. 70. Hofstetter HW. Useful age-amplitude formula. Opt World 99. Stelmack JA, Frith T, Van Koevering D, et al. Visual function in pa- 1950;38: 42-5. tients followed at a Veterans Affairs polytrauma network site: an 71. Mellick A. Convergence deficiency; an investigation into the electronic medical record review. Optometry 2009;80(8): results of treatment. Br J Ophthalmol 1950;34(1):41-6. 419-24. 72. Smith A. Convergence deficiency: an occupational study. Br 100. Burke JP, Shipman TC, Watts MT. Convergence insufficiency in Orthoptic J 1951;8:56-70. thyroid eye disease. J Pediatr Ophthalmol Strabismus 1993;30(2): 73. Borsting E, Chase C, Tosha C, et al. Longitudinal study of visual 127-9. dis- comfort symptoms in college students. Optom Vis Sci 101. Cooper J, Pollak GJ, Ciuffreda KJ, et al. Accommodative and ver- 2008;85(10): 992-8. gence findings in ocular myasthenia: a case analysis. J 74. Eames TH. Improvement in reading following the correction of Neuroophthalmol 2000;20(1):5-11. the eye defects of non-readers. Am J Ophthalmol 1934;17:324-5. 102. Colavito J, Cooper J, Ciuffreda KJ. Non-ptotic ocular myasthenia 75. Eames TH. Low fusion convergence as a factor in reading gravis: a common presentation of an uncommon disease. disability. Am J Ophthalmol 1934;17:709-10. Optometry 2005;76(7):363-75. 76. Eames TH. The ocular characteristics of unselected and a 103. Biousse V, Skibell BC, Watts RL, et al. Ophthalmologic features of comparison of reading disability groups. J Educ Res 1932;XXV: Parkinson’s disease. Neurology 2004;62(2):177-80. 211-5. 104. Racette BA, Gokden MS, Tychsen LS, et al. Convergence insuffi- 77. Park G, Burri C. The relation of various eye conditions and ciency in idiopathic Parkinson’s disease responsive to levodopa. reading achievement. J Ed Psych 1943;34:290-9. Strabismus 1999;7(3):169-74. 78. Granet DB, Gomi CF, Ventura R, et al. The relationship between 105. Ohtsuka K, Maekawa H, Takeda M, et al. Accommodation and convergence insufficiency and ADHD. Strabismus 2005;13(4): convergence insufficiency with left middle cerebral artery 163-8. occlusion. Am J Ophthalmol 1988;106(1):60-4. 79. Borsting E, Rouse M, Chu R. Measuring ADHD behaviors in children with symptomatic accommodative dysfunction or 106. Scheiman M, Cooper J, Mitchell GL, et al. A survey of treatment 131. Wick B. Vision training for presbyopic nonstrabismic patients. modalities for convergence insufficiency. Optom Vis Sci Am J Optom Physiol Optics 1977;54(4):244-7. 2002;79(3):151-7. 132. Cohen AH, Soden R. Effectiveness of visual therapy for 107. Patwardhan SD, Sharma P, Saxena R, et al. Preferred clinical convergence insufficiencies for an adult population. J Am Optom practice in convergence insufficiency in India: a survey. Indian J Assoc 1984; 55(7):491-4. Ophthalmol 2008;56(4):303-6. 133. Ciuffreda KJ, Rutner D, Kapoor N, et al. Vision therapy for 108. Abrams D, Duke-Elder S. Duke-Elder’s practice of refraction, oculomotor dysfunctions in acquired brain injury: a 10th ed. Edinburgh; New York: Churchill Livingstone; 1993. retrospective analysis. Optometry 2008;79(1):18-22. 109. Press LJ. Applied concepts in vision therapy, with accompanying 134. Randomized clinical trial of treatments for symptomatic disk. St. Louis: Mosby; 1997. convergence insufficiency in children. Arch Ophthalmol 110. Von Noorden GK, Campos EC. Binocular vision and ocular 2008;126(10):1336-49 . motility: theory and management of strabismus, 3rd ed. St. Louis: 135. Worrell BE Jr, Hirsch MJ, Morgan MW. An evaluation of prism Mosby; 2001:406-7. prescribed by Sheard’s criterion. American Journal of Optometry 111. Cooper J. Review of computerized orthoptics with specific and Archives of American Academy of Optometry 1971;48(5): regard to convergence insufficiency. Am J Optom Physiol Optics 373-6. 1988;65(6): 455-63. 136. Saladin J. Horizontal prism prescription. In: Cotter S, ed. Clinical 112. Cooper J. Diagnosis and treatment of accommodative and use of prisms: a spectrum of applications. St Louis: Mosby; vergence anomalies using computerized vision therapy. Practical 1995:134. Optometry 1998;9:6-10. 137. Stavis M, Murray M, Jenkins P, et al. Objective improvement from 113. Griffin JR, Grisham JD. Binocular anomalies: diagnosis and vision base-in prisms for reading discomfort associated with mini- therapy, 4th ed. Boston: Butterworth-Heinemann; 2002. convergence insufficiency type exophoria in school children. 114. Saladin J. Horizontal prism prescription in clinical use of prisms: a Binocul Vis Strabismus Q 2002;17(2):135-42. spectrum of applications. In: SC, editor. Horizontal prism 138. Scheiman M, Cotter S, Rouse M, et al. Randomised clinical trial of prescription in clinical use of prisms: a spectrum of applications. the effectiveness of base-in prism reading glasses versus placebo St Louis: Mosby; 1995: 109-47. reading glasses for symptomatic convergence insufficiency in 115. von Noorden GK. Resection of both medial rectus muscles in children. Br J Ophthalmol 2005;89(10):1318-23. organic convergence insufficiency. Am J Ophthalmol 1976;81(2): 139. Dusek WA, Pierscionek BK, McClelland JF. An evaluation of 223-6. clinical treatment of convergence insufficiency for children with 116. Gallaway M, Scheiman M, Malhotra K. The effectiveness of pencil reading difficulties. BMC Ophthalmol 2011;11(1):21. pushups treatment for convergence insufficiency: a pilot study. 140. Teitelbaum B, Pang Y, Krall J. Effectiveness of base in prism for Optom Vis Sci 2002;79(4):265-7. presbyopes with convergence insufficiency. Optom Vis Sci 2009; 117. Scheiman M, Mitchell GL, Cotter S, et al. A randomized clinical 86(2):153-6. trial of treatments for convergence insufficiency in children. Arch 141. Hawkeswood R. A case of surgery for convergence insufficiency. Ophthalmol 2005;123(1):14-24. Aust Orthoptic J 1970-1971;11:47-8. 118. Scheiman M, Mitchell GL, Cotter S, et al. A randomized clinical 142. Biedner B. Treatment of convergence insufficiency by single trial of vision therapy/orthoptics versus pencil pushups for the medial rectus muscle slanting resection. Ophthalm Surg Lasers treatment of convergence insufficiency in young adults. Optom 1997;28(4):347-8. Vis Sci 2005; 82(7):583-95. 143. Binion WW. The surgical treatment of intermittent exotropia. 119. Cooper J, Feldman J. Operant conditioning of fusional Am J Ophthalmol 1966;61(5 Pt 1):869-74. convergence ranges using random dot stereograms. Am J Optom 144. Choi DG, Rosenbaum AL. Medial rectus resection(s) with Physiol Optics 1980;57(4):205-13. adjustable suture for intermittent exotropia of the convergence 120. Daum KM, Rutstein RP, Eskridge JB. Efficacy of computerized ver- insufficiency type. J AAPOS 2001;5(1):13-7. gence therapy. Am J Optom Physiol Optics 1987;64(2):83-9. 145. Choi MY, Hwang JM. The long-term result of slanted medial 121. Kertesz AE. The effectiveness of wide-angle fusional stimulation rectus resection in exotropia of the convergence insufficiency in the treatment of convergence insufficiency. Invest Ophthalmol type. Eye 2006;20(11):1279-83. Vis Sci 1982;22(5):690-3. 146. Choi MY, Hyung SM, Hwang JM. Unilateral recession-resection in 122. Sommers W, Happel A, Phillips J. Use of personal microcomputer children with exotropia of the convergence insufficiency type. for orthoptic therapy. J Am Optom Assoc 1984;55:217-22. Eye 2007;21(3):344-7. 123. Convergence Insufficiency Treatment Trial Study Group. CITTS. 147. Pantano F. Orthoptic treatment of convergence insufficiency: a Randomized clinical trial of treatments for symptomatic two year follow-up report. Am Orthoptic J 1982;32:73-80. convergence insufficiency in children. Arch Ophthalmol 148. Shin HS, Park SC, Maples WC. Effectiveness of vision therapy for 2008;126(10):1336-49. convergence dysfunctions and long-term stability after vision 124. Cooper J, Feldman J. Reduction of symptoms in binocular therapy. Ophthalmic Physiol Opt 2011;31(2):180-9. anomalies using computerized home therapy-HTS. Optometry 149. Grisham JD, Bowman MC, Owyang LA, et al. Vergence 2009;80(9):481-6. orthoptics: validity and persistence of the training effect. Optom 125. Serna A, Rogers DL, McGregor ML, et al. Treatment of Vis Sci 1991; 68(6):441-51. symptomatic convergence insufficiency with a home-based 150. Alvarez TL, Vicci VR, Alkan Y, et al. Vision therapy in adults with computer orthoptic exercise program. J AAPOS 2011. convergence insufficiency: clinical and functional magnetic reso- 126. Grisham JD. Visual therapy results for convergence insufficiency: nance imaging measures. Optom Vis Sci 2010;87(12):E985-1002. a literature review. American Journal of Optometry and 151. Ciuffreda KJ. The scientific basis for and efficacy of optometric Physiological Optics 1988;65(6):448-54. vision therapy in nonstrabismic accommodative and vergence 127. Mayou S. The treatment of convergence deficiency. Br Orthopt J disorders. Optometry 2002;73(12):735-62. 1945;3:72-82. 152. Scheiman M, Wick B. Clinical management of binocular vision: 128. Lyle, Jackson. Practical orthoptics in the treatment of squint. heterophoric, accommodative, and eye movement disorders. London: Lewis 1940: 203-07. Philadelphia: J.B. Lippincott Co; 2008. 129. Stutterheim NA. Eyestrain and convergence. London: H. K. 153. Atzmon D, Nemet P, A I, Karni E. A randomized prospective Lewis, Co; 1937. masked and matched comparative study of orthoptic treatment 130. Burian HM. Symposium: convergence insufficiency; summary. Am versus conventional reading tutoring treatment for reading Orthoptic J 1953;3:26. disabilities in 62 children. Binocul Vis Eye Musc Surg 1994;9:91-5. 154. Goss DA, Downing B, Lowther A, et al. The Effect of HTS vision Corresponding author: Jeffrey Cooper, O.D., State therapy conducted in a school setting on reading skills in third University of New York, State College of Optometry, and fourth grade students. Optom Vis Dev 2007;38(1):27-32. 155. Scheiman M, Gwiazda J, Li T. Non-surgical interventions for 33 W. 42nd Street, New York, NY 10036. convergence insufficiency. Cochrane Database Syst Rev Email: [email protected] 2011;3:CD006768. 156. Scheiman M, Rouse M, Kulp MT, et al. Treatment of convergence insufficiency in childhood: a current perspective. Optom Vis Sci 2009;86(5):420-8. 157. Daum KM. A comparison of the results of tonic and phasic vergence training. Am J Optom Physiol Optics 1983;60(9): 769-75. 158. Hoffman L, Cohen A, Feuer G. Effectiveness of non-strabismic optometric vision training in a private practice. American Journal of Optometry and Archives of the American Academy of Optometry 1973;50:813-6. 159. Daum KM. Classification criterion for success in the treatment of convergence insufficiency. Am J Optom Physiol Optics 1984;61(1): 10-5. 160. Birnbaum MH, Soden R, Cohen AH. Efficacy of vision therapy for convergence insufficiency in an adult male population. J Am Optom Assoc 1999;70(4):225-32. 161. Group. CITTS. The convergence insufficiency treatment trial: design, methods, and baseline data. Ophthalmic Epidemiol 2008;15(1):24-36 Cooper and Jamal Literature Review 21

2268 Appendix 1 CI Symptom Survey Do not give examples. 2325 2269 Subject instructions: Please answer the following ques- 2326 2270 Clinician instructions: Read the following subject instruc- tions about how your eyes feel when reading or doing close 2327 2271 tions and then each item exactly as written. If subject re- work. 2328 2272 sponds with ‘‘yes,’’ please qualify with frequency choices. 2329 2273 2330 2274 2331 2275 2332 2276 2333 2277 (not very often, 2334 Never Infrequently) Sometimes Fairly often Always 2278 2335 2279 1. Do you eyes feel tired when reading or doing close work? 2336 2280 2. Do your eyes feel uncomfortable when reading 2337 2281 or doing close work? 2338 2282 3. Do you have headaches when reading or doing close work? 2339 4. Do you feel sleepy when reading or doing close work? 2283 2340 5. Do you lose concentration when reading or doing 2284 close work? 2341 2285 6. Do you have trouble remembering what you have read? 2342 2286 7. Do you have double vision when reading or doing 2343 2287 close work? 2344 2288 8. Do you see the words move, jump, swim, or appear 2345 2289 to float on the page when reading or doing close work? 2346 2290 9. Do you feel like you read slowly? 2347 2291 10. Do your eyes ever hurt when reading or doing close work? 2348 2292 11. Do your eyes ever feel sore when reading or 2349 2293 doing close work? 2350 12. Do you feel a ‘‘pulling’’ feeling around your eyes 2294 2351 when reading or doing close work? 2295 13. Do you notice the words blurring or coming in and 2352 2296 out of focus when reading or doing close work? 2353 2297 14. Do you lose your place white reading or doing close work? 2354 2298 15. Do you have to re-read the same line of words 2355 2299 when reading? 2356 2300 _! 0_! 1_! 2_! 3_! 4 2357 2301 2358 2302 2359 2303 2360

2304 Q14 assigned the Home Therapy System computer software at 2361 ½ Š Appendix 2 --- 2305 home.123 The HTS program was chosen because it is used 2362 2306 A detailed description of each procedure and the protocol by more optometrists and ophthalmologists than any other 2363 2307 used in the CITT study for each group is provided in the home vision therapy system because it uses scientific prin- 2364 2308 following site: http://optometry.osu.edu/research/CITT/ cipals of operant conditioning with random dot stereo- 2365 2309 pdfs/MOP_Chapter08.pdf. The CITT was made up of the grams, it is easy to use, and has performance graphs to 2366 2310 following treatment arms: monitor each session and weekly performances. Subjects 2367 2311 Home-based pencil push-up therapy group were required to demonstrate their ability to perform these 2368 2312 The home-based pencil push-up therapy utilizes a small procedures to the therapist in the office before beginning 2369 2313 letter on the pencil and an index card in the background to therapy at home. Therapy required 20 minutes per day 2370 2314 provide physiologic diplopia control. Although a physio- (15 minutes for HTS and 5 minutes for pencil push-ups). 2371 2315 logic diplopia control is not universally used in standard In-office therapy group 2372 2316 clinical practice, it has often been recommended in the Patients in the in-office therapy group had 12 weekly 2373 2317 literature 134,161 to ensure that the subject is not vision therapy sessions that included a multitude of ac- 2374 2318 suppressing. commodative and vergence activities. A summary of the 2375 2319 Home therapy group protocol adopted by the CITT group is presented. In 2376 2320 The home-based vt/orthoptics group was asked to prac- addition, patients assigned to the in-office protocol had 2377 2321 tice the same well-defined pencil push-up procedure as the home therapy, which included pencil push-ups and the HTS 2378 161 Q15 2322 home-based pencil push-up group. In addition, they were computer software. ½ Š 2379 2323 2380 2324 2381

FLA 5.1.0 DTD Š OPTM1143_proof Š 3 December 2011 Š 1:30 pm Cooper and Jamal Literature Review 21

2268 Appendix 1 CI Symptom Survey Do not give examples. 2325 2269 Subject instructions: Please answer the following ques- 2326 2270 Clinician instructions: Read the following subject instruc- tions about how your eyes feel when reading or doing close 2327 2271 tions and then each item exactly as written. If subject re- work. 2328 2272 sponds with ‘‘yes,’’ please qualify with frequency choices. 2329 2273 2330 2274 2331 2275 2332 2276 2333 2277 (not very often, 2334 Never Infrequently) Sometimes Fairly often Always 2278 2335 2279 1. Do you eyes feel tired when reading or doing close work? 2336 2280 2. Do your eyes feel uncomfortable when reading 2337 2281 or doing close work? 2338 2282 3. Do you have headaches when reading or doing close work? 2339 4. Do you feel sleepy when reading or doing close work? 2283 2340 5. Do you lose concentration when reading or doing 2284 close work? 2341 2285 6. Do you have trouble remembering what you have read? 2342 2286 7. Do you have double vision when reading or doing 2343 2287 close work? 2344 2288 8. Do you see the words move, jump, swim, or appear 2345 2289 to float on the page when reading or doing close work? 2346 2290 9. Do you feel like you read slowly? 2347 2291 10. Do your eyes ever hurt when reading or doing close work? 2348 2292 11. Do your eyes ever feel sore when reading or 2349 2293 doing close work? 2350 12. Do you feel a ‘‘pulling’’ feeling around your eyes 2294 2351 when reading or doing close work? 2295 13. Do you notice the words blurring or coming in and 2352 2296 out of focus when reading or doing close work? 2353 2297 14. Do you lose your place white reading or doing close work? 2354 2298 15. Do you have to re-read the same line of words 2355 2299 when reading? 2356 2300 _! 0_! 1_! 2_! 3_! 4 2357 2301 2358 2302 2359 2303 2360

2304 Q14 assigned the Home Therapy System computer software at 2361 ½ Š Appendix 2 --- 2305 home.123 The HTS program was chosen because it is used 2362 2306 A detailed description of each procedure and the protocol by more optometrists and ophthalmologists than any other 2363 2307 used in the CITT study for each group is provided in the home vision therapy system because it uses scientific prin- 2364 2308 following site: http://optometry.osu.edu/research/CITT/ cipals of operant conditioning with random dot stereo- 2365 2309 pdfs/MOP_Chapter08.pdf. The CITT was made up of the grams, it is easy to use, and has performance graphs to 2366 2310 following treatment arms: monitor each session and weekly performances. Subjects 2367 2311 Home-based pencil push-up therapy group were required to demonstrate their ability to perform these 2368 2312 The home-based pencil push-up therapy utilizes a small procedures to the therapist in the office before beginning 2369 2313 letter on the pencil and an index card in the background to therapy at home. Therapy required 20 minutes per day 2370 2314 provide physiologic diplopia control. Although a physio- (15 minutes for HTS and 5 minutes for pencil push-ups). 2371 2315 logic diplopia control is not universally used in standard In-office therapy group 2372 2316 clinical practice, it has often been recommended in the Patients in the in-office therapy group had 12 weekly 2373 2317 literature 134,161 to ensure that the subject is not vision therapy sessions that included a multitude of ac- 2374 2318 suppressing. commodative and vergence activities. A summary of the 2375 2319 Home therapy group protocol adopted by the CITT group is presented. In 2376 2320 The home-based vt/orthoptics group was asked to prac- addition, patients assigned to the in-office protocol had 2377 2321 tice the same well-defined pencil push-up procedure as the home therapy, which included pencil push-ups and the HTS 2378 161 Q15 2322 home-based pencil push-up group. In addition, they were computer software. ½ Š 2379 22 2323 Optometry, Vol -, No -, - 2012 2380 2324 2381 2382 2439 Phase One 2383 2440 Gross convergence, Positive FusionalFLA Vergence 5.1.0and Monocular DTD AccommodativeŠ OPTM1143_proof Therapy Š 3 December 2011 Š 1:30 pm 2384 Techniques 2441 2385 2442 2386 Gross Convergence Positive Fusional Vergence Monocular Accommodative Therapy 2443 2387 Brock String Vectograms (Quoits/Clown) Loose Lens Accommodative Rock 2444 2388 Barrell Card Computer Orthoptics (RDS) Letter Chart Accommodative Rock 2445 2389 Life Saver Cards 2446 2390 2447 Home VT 2391 Brock String Barrell Card 2448 2392 Loose Lens Accommodative Rock Life Saver Cards 2449 2393 Letter Chart Accommodative Rock Home Therapy Software Disk (HTS) 2450 2394 2451 2395 2452 2396 Phase Two 2453 2397 Ramp Fusional Vergence and Monocular Accommodative Therapy 2454 2398 2455 2399 Techniques 2456 2400 Ramp Fusional Vergence Monocular Accommodative Facility 2457 2401 Vectograms (Quoits/Clowns) Loose Lens Accommodative Rock 2458 Computer Orthoptics (RDS) Letter Chart Accommodative Rock 2402 Aperature Rule 2459 2403 Eccentric Circles 2460 2404 Home VT 2461 2405 Random Dot Card Loose lens Accommodative Therapy 2462 2406 Eccentric Circles Letter Chart Accommodative Therapy 2463 2407 HTS (base-out, base-in, and autoslide vergence) 2464 2408 2465 2409 2466 2410 Phase Three 2467 2411 Jump Fusional Vergence and Binocular Accommodative Facility 2468 2412 2469 2413 Techniques 2470 Jump Fusional Vergence Binocualar Accommodative Facility 2414 Vectograms (Quoits/Clown) Binocular Accommodative Facility 2471 2415 Computer Orthoptics (RDS) 2472 2416 Aperature Rule 2473 2417 Eccentric Circles 2474 2418 Loose Prism Facility 2475 2419 Home VT 2476 2420 Eccentric Circles Loose Prism Jumps 2477 2421 Binocular Accommodative Facility Random Dot Card 2478 2422 HTS (base-out, base-in, and autoslide vergence) 2479 2423 2480 2424 Maintenance Therapy 2481 2425 (for successfully treated patients) 2482 2426 2483 2427 2484 2428 2485 2429 2486 2430 2487 2431 2488 2432 2489 2433 2490 2434 2491 2435 2492 2436 2493 2437 2494 2438 2495

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2496 2552 2497 2553 2498 Phase 1 2554 2499 Gross convergence Endpoint 2555 2500 A. Brock string (level 1) Converge to a bead 2.5 cm from nose 2556 2501 B. Brock string (level 2) Voluntarily converge to a bead 2.5 cm from nose 2557 2502 C. Barrel card Fuse each of the 3 beads, hold fusion for 5 seconds, for 10 repetitions 2558 Vergence Endpoint 2503 D 2559 2504 D. Vectograms (quoits/clown) base-out 30 Base-out 2560 E. Computer orthoptics (RDS) base-out 45D Base-out with large, medium, small RDS targets 2505 2561 F. Lifesaver cards Able to clear all 4 levels of difficulty and hold fusion for at least 5 seconds 2506 Accommodation Endpoint 2562 2507 G. Loose lens accommodative rock Clear 11.50/-3.00, 10 cycles per minute 2563 2508 H. Letter chart accommodative rock Clear near chart at age-appropriate distance and be able to clear to 2564 2509 distance chart 2565 2510 Phase 2 2566 2511 Vergence Endpoint 2567 2512 I. Vectograms (quoits/clown) 25D Base-out, 12D Base-in (letter ‘‘L’’) 2568 D 2513 J. Computer orthoptics (RDS) 45 Base-out with large RDS targets 2569 15D Base-in with large RDS targets 2514 D D 2570 2515 K. Aperture rule 30 Base-out (card 12), 15 Base-in (card 6) 2571 L. Eccentric circles 30D Base-out/ 15 base-in 2516 2572 Accommodation Endpoint 2517 M. Loose lens accommodative rock Clear 12.00/-6.00, 10 cycles per minute 2573 2518 N. Letter chart accommodative rock Clear near chart at age-appropriate distance, change fixation and clear far 2574 2519 letter chart at 3 m for 10 cycles per minute 2575 2520 Phase 3 2576 2521 Vergence Endpoint 2577 2522 O. Vectograms (quoits/clown) jump vergence Alternately fuse 25D base-out and 15D base-in for at least 10 cycles per minute 2578 2523 Computer orthoptics (RDS) jump vergence Alternately fuse 45D base-out and 15D base-in 2579 D D 2524 Q. Aperture rule jump vergence Using 8 base-out/4 base-in prism flippers, achieve clear, single binocular 2580 vision with card 8 for convergence (28D Base- out to 16D base-out) and card 2525 D Db 2581 2526 4 for divergence (2 base-in to 14 Base-in) for 10 cycles per minute 2582 R. Eccentric circles jump vergence Regain clear, chiastopic fusion after fusion is disrupted with a card separation 2527 2583 of 12 cm (30D base-out) and clear, orthopic fusion with a card separation of 2528 6 cm (15D Base-in). 2584 2529 Switch between chiastopic and orthoptic fusion with the cards held 6 cm apart 2585 2530 for 20 repetitions 2586 2531 S. Loose prism facility For jump vergence, achieve single, clear, binocular vision while viewing a 20/30 2587 2532 target at 40 cm though 25D base-out and then without prism for at least 2588 2533 10 cycles per minute. 2589 2534 For jump divergence, achieve single, clear, binocular vision while viewing 2590 D 2535 a 20/30 target at 40 cm through 12 base-in and then without prism for 2591 2536 at least 10 cycles per minute. 2592 2537 Accommodation Endpoint 2593 T. Binocular clear vision while viewing 20/30 Single, accommodative facility Q16 2538 ½ Š 2594 point at 40 cm through 12.00 and alternately 2539 –2.00 for at least 13 cycles per minute 2595 2540 without suppression. 2596 2541 2597 2542 2598 2543 2599 2544 2600 2601 2545 2602 2546 2603 2547 2604 2548 2605 2549 2606 2550 2607 2551 2608

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