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Screening for Visual Impairment in Children Ages 1–5 Years: Update for the USPSTF

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Screening for Visual Impairment in Children Ages 1–5 Years: Update for the USPSTF Screening for Visual Impairment in Children Ages 1–5 Years: Update for the USPSTF AUTHORS: Roger Chou, MD,a,b,c Tracy Dana, MLS,a and abstract Christina Bougatsos, BSa CONTEXT: Screening could identify preschool-aged children with vi- aOregon Evidence-Based Practice Center and Departments of bMedicine and cMedical Informatics and Clinical Epidemiology, sion problems at a critical period of visual development and lead to Oregon Health & Science University, Portland, Oregon treatments that could improve vision. KEY WORDS OBJECTIVE: To determine the effectiveness of screening preschool- impaired visual acuity, vision screening, vision tests, preschool aged children for impaired visual acuity on health outcomes. children, refractive errors, amblyopia, amblyogenic risk factors, random dot E stereoacuity test, MTI photoscreener, patching, METHODS: We searched Medline from 1950 to July 2009 and the Co- systematic review chrane Library through the third quarter of 2009, reviewed reference ABBREVIATIONS lists, and consulted experts. We selected randomized trials and con- USPSTF—US Preventive Services Task Force trolled observational studies on preschool vision screening and treat- logMAR—logarithmic minimal angle of resolution ALSPAC—Avon Longitudinal Study of Parents and Children ments, and studies of diagnostic accuracy of screening tests. One in- RR—relative risk vestigator abstracted relevant data, and a second investigator CI—confidence interval checked data abstraction and quality assessments. VIP—Vision in Preschoolers PLR—positive likelihood ratio RESULTS: Direct evidence on the effectiveness of preschool vision NLR—negative likelihood ratio screening for improving visual acuity or other clinical outcomes re- MTI—Medical Technology and Innovations OR—odds ratio mains limited and does not adequately address whether screening is D—diopter(s) more effective than no screening. Regarding indirect evidence, a num- PEDIG—Pediatric Eye Disease Investigator Group ber of screening tests have utility for identification of preschool-aged MeSH—Medical Subject Headings children with vision problems. Diagnostic accuracy did not clearly dif- RCT—randomized controlled trial fer for children stratified according to age, although testability rates www.pediatrics.org/cgi/doi/10.1542/peds.2010-0462 were generally lower in children 1 to 3 years of age. Treatments for doi:10.1542/peds.2010-0462 amblyopia or unilateral refractive error were associated with mild Accepted for publication Oct 13, 2010 improvements in visual acuity compared with no treatment. No study Address correspondence to Roger Chou, MD, Corresponding has evaluated school performance or other functional outcomes. author contact information: Oregon Evidence-Based Practice Center, Oregon Health & Science University, Mail Code BICC, 3181 CONCLUSIONS: Although treatments for amblyopia or unilateral re- SW Sam Jackson Park Rd, Portland, OR 97239. E-mail: fractive error can improve vision in preschool-aged children and [email protected] screening tests have utility for identifying vision problems, additional PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275). studies are needed to better understand the effects of screening com- Copyright © 2011 by the American Academy of Pediatrics pared with no screening. Pediatrics 2011;127:e442–e479 FINANCIAL DISCLOSURE: The authors have indicated they have no financial relationships relevant to this article to disclose. e442 CHOU et al REVIEW ARTICLES TABLE 1 Amblyogenic Risk Factors TABLE 2 Visual Acuity Tests Anisometropia* (spherical or cylindrical) Ͼ 1.50 D Test Description Applicable Any manifest strabismus Age, y Hyperopia Ͼ 3.50 D in any meridian Allen cards Test involving 4 flash cards that contain 7 schematic figures; the figures 2–4 Any media opacity Ͼ 1 mm in size are identified from various distances Astigmatism Ͼ 1.5 D at 90° or 180° Ͼ in oblique HOTV Test involving identification of the letters H, O, T, and V; the letters Ͼ4 axis (Ͼ10° eccentric to 90° or 180°) decrease in size from the top to the bottom of the chart Ptosis Յ 1 mm margin reflex distance—the Lea symbols Test involving matching the symbols from the cards to the symbols on 2–4 distance from the corneal light reflex to the the wall; the symbols decrease in size from the top to the bottom of upper lid margin; a standard objective the chart measurement of ptosis Snellen Test involving a chart with 11 lines of letters; the first line consists of 1 Ͼ4 Visual acuity: per age-appropriate standards very large letter, and each row below it has increasing numbers of D ϭ diopter. letters that decrease in size * Anisometropia is a difference in the refractive power of Tumbling E Test involving the letter E presented with the arms pointing in different Ͼ4 the two eyes. directions; the letters decrease in size from the top to the bottom of Reprinted with permission from Donahue et al.10 (p 315). the chart Data sources: American Academy of Pediatrics11 and Prevent Blindness America.12 Visual impairment in young children TABLE 3 Measurements of Visual Acuity for inclusion. This review was limited can reduce quality of life1 and may af- Snellen Decimal LogMAR to the published, English-language fect function and school performance. ft m studies available. In the United States, 1% to 5% of 20/20 6/6 1.00 0.00 Data from full-text articles were ab- Ϫ preschool-aged children are esti- 20/30 6/9 0.67 0.18 stracted by 1 investigator and verified 20/40 6/12 0.50 Ϫ0.30 mated to have vision impairment that 20/60 6/18 0.33 Ϫ0.48 by a second investigator. We converted is most commonly related to amblyo- 20/80 6/24 0.25 Ϫ0.60 visual acuity from Snellen to loga- pia, strabismus, and refractive er- 20/100 6/30 0.20 Ϫ0.70 rithmic minimal angle of resolution Ϫ rors.2–5 Vision impairment associated 20/160 6/48 0.13 0.90 20/200 6/60 0.10 Ϫ1.00 (logMAR) measurements by using 13 with amblyopia is not immediately cor- Visual impairment is 20/50 or worse; legal blindness is published conversion charts. Two rectable with refractive lenses, is un- 20/200 or worse. authors independently rated the inter- 13 likely to resolve spontaneously,6 and Data source: Holladay. nal validity of each study as “good,” can become irreversible.7,8 Strabis- “fair,” or “poor” on the basis of criteria mus is the most common amblyogenic METHODS developed by the USPSTF (Appendix risk factor (Table 1). Strabismus can Using the methods developed by the 4).15,16 Discrepancies were resolved by also inhibit development of normal USPSTF, we developed an analytic discussion and consensus. For diag- binocular vision in the absence of am- framework and key questions (Fig 1) to nostic accuracy studies, we used the blyopia and result in psychosocial con- guide our literature search and re- diagti procedure in Stata 10 (Stata sequences.9 Preschool vision screen- view.15 We searched Ovid Medline from Corp, College Station, TX) to calculate ing (Table 2), which typically includes a 1950 to July 2009 and the Cochrane sensitivities, specificities, and likeli- measurement of visual acuity (Table Central Register of Controlled Trials hood ratios. When the reference stan- 3), could help identify children who and the Cochrane Database of System- dard was applied in a random sample might benefit from early interventions. atic Reviews through the third quarter of of negative screens, we corrected for In 2004, the US Preventive Services 2009 (Appendix 1). We supplemented verification bias by using the method 17 Task Force (USPSTF) recommended electronic searches with reviews of ref- of Begg and Greenes. We classified 18 screening to detect amblyopia, stra- erence lists and by consulting experts. likelihood ratios as shown in Table 4. bismus, and defects in visual acuity Fig 2 shows the flow of studies from We evaluated applicability to populations in children younger than 5 years of initial identification of titles and ab- likely to be encountered in primary care age (“B recommendation”).14 In 2009, stracts to final inclusion or exclusion. screening settings on the basis of re- the USPSTF commissioned a new ev- We selected studies that pertained to cruitment from primary care settings, idence review to update its recom- screening, diagnosis, and treatment of the prevalence of visual conditions, and mendations. The purpose of this re- visual impairment in children 1 to 5 the severity of visual impairment. port is to systematically evaluate the years of age (for details, see Appen- We assessed the overall strength of current evidence on preschool vision dixes 2 and 3). Two reviewers evalu- the body of evidence for each key ques- screening. ated each study to determine eligibility tion (good, fair, or poor) by using PEDIATRICS Volume 127, Number 2, February 2011 e443 KQ1, 1a Risk factor Screening Treatment Final health and assessment functional capacity outcomes “Risk-reduction” intervention Correcting refractive errors KQ2 Use of amblyopic eye Normal Correction of visual disturbances Low risk Improved visual acuity KQ3, 3a Reduced long-term amblyopia Preschool-aged KQ5 children, Better school performance ages 1−5 y Abnormal High risk KQ4 KQ6 Harms of screening Harms of treatment Key questions: 1. Is vision screening in children aged 1−5 y associated with improved health outcomes? 1a. Does effectiveness of vision screening in children aged 1−5 y vary in different age groups? 2. What is the accuracy and reliability of risk-factor assessment for identifying children aged 1−5 y at increased risk for vision impairment? 3. What is the accuracy of screening tests for vision impairment in children aged 1−5 y? 3a. In children aged 1−5 y, does accuracy of screening tests for vision impairment vary in different age groups? 4. What are the harms of vision screening for children aged 1−5 y? 5. What is the effectiveness of treatment for vision impairment in children aged 1−5 y? 6.
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