Generating value “ CASE REPORT for optometrists “ SUPPORT An unusual case of myopic shift post acquired brain injury
SAVINGS by Farrah F. SUnDerJi, oD & surgery and brain tumours; or a Farrah F. Sunderji, O.D. Catherine heyMan, oD, Faao, traumatic brain injury (TBI) result- Resident, Pediatric Optometry CE Seminars FCoVD ing from an external insult (Table and Vision Therapy Centralized 1).3,4 Males are more at risk for Southern California College Billing both a CVA and TBI. Using Table of Optometry Background 1 for classification purposes, this 2006-2007 n the United States, approx- case report illustrates an unusual Catherine Heyman, O.D., Discount imately one person every 16 presentation of myopic shift post AUTONOMY Local Presence I F.A.A.O, FCOVD seconds suffers some form of ac- ABI due to the presence of mul- 1 Southern California College quired brain injury (ABI). An ABI tiple brain tumours, brain surgery of Optometry opto.com results from an event that occurs for removal of the tumours, shunt Faculty Advisor Optosys®2 suddenly and results in neurologi- placement for hydrocephalus, and Training cal dysfunctions.2 The two major a CVA post-surgery. Securo Vision CONTROL events that cause an ABI include Ocular and visual problems are In memory of the late Michael Rouse,OD VALUE an internal insult such as a cerebro- frequent consequences of an ABI. Web site vascular accident (CVA), brain Cohen1 explains that following a creation Marketing RÉSUmÉ Un CAS InHABITUEL D’ÉCART MYOPIQUE SURVEnAnT À LA SUITE D’UnE LÉSIOn CÉRÉBRALE ACQUISE Financing Contexte et 22,2 mmol/L; le patient a fait un AVC Lors d’une visite de suivi un mois plus tard, Des problèmes oculovisuels surviennent après l’intervention, ce qui a causé une sa meilleure acuité visuelle corrigée à une fréquemment après une lésion hémiparésie du côté gauche; un shunt a été distance s’était améliorée à 6/60 dans les cérébrale acquise (LCA). Une revue de la posé pour diminuer l’enflure dans la région deux yeux grâce à la nouvelle prescription. Succession OptoPlus documentation révèle que bon nombre de l’excision et dans les nerfs optiques. Liste Sa rétinoscopie sous cycloplégie n’a Planning Benchmarking de patients présentent un déplacement des médicaments : Cartia, lisinopril, Toprol présenté aucune variation de la myopie Banner myopique de l’erreur de réfraction après XL, prednisone, Reglan et Temodar. Le ou de l’astigmatisme, toutefois, l’œdème un traumatisme cérébral, qui est une patient a fait l’objet d’une chimiothérapie du disque s’est résorbé. pour traiter les restes de la tumeur. Son forme de LCA. Trois formes d’évolution Conclusion sont présentées. Le plus souvent, la dernier examen visuel en 2004 indiquait une Ce cas illustre une présentation myopie se résorbe sous cycloplégie. En erreur de réfraction de -2,50-1,25×080 dans inhabituelle d’un déplacement myopique deuxième lieu, le déplacement peut son œil droit et de -3,00-0,75×080 dans son JOIN the Largest Network of Optometrists in Canada à la suite d’une lésion cérébrale acquise. être temporaire et, en troisième lieu, cas œil gauche avec acuité visuelle de 6/7,5 L’état du patient n’a cessé de se détériorer, le moins courant, la myopie augmente dans les deux yeux. Il s’est présenté à notre et celui-ci n’y a pas survécu. On ne sait avec le temps. Le présent rapport de clinique avec une acuité visuelle assistée pas si la myopie et l’astigmatisme ont cas, même s’il n’est pas attribuable à un de 8/100 (6/110) dans les deux yeux et une CONTACT US AT: [email protected] pris de l’ampleur ou s’ils se sont stabilisés. traumatisme cérébral, est un exemple du hémianopsie homonyme gauche après Même si la cause de cet état n’est pas cas le moins courant. évaluation de la périmétrie par comptage • Purchasing Group des doigts. Une rétinoscopie sous pleinement comprise et qu’elle nécessite Rapport de cas cycloplégie a révélé -6,00-3,00×090 dans d’autres examens, une correction optique • Great Discounts Le patient, un homme de 63 ans, a subi, son œil droit et -6,00-2,00×090 dans son appropriée a toutefois permis d’améliorer 15 mois avant sa première évaluation, œil gauche. Un examen du fond d’œil sous la qualité de vie du patient. • MEMBERSHIP FREE OF CHARGE l’excision d’une tumeur dans le lobe pupille dilatée a indiqué une légère enflure mots clés : tumeurs, traitement de la temporal frontal droit. Il a reçu avant et après des deux nerfs optiques. Les taux de glucose myopie, lésion cérébrale. l’intervention 4 mg QD qui a fait fluctuer sanguin ont varié entre 103 et 140. • 100 accredited suppliers son taux de glucose sanguin entre 5,72 • You control your price, your inventory, your clinic T.: 1-800-363-4096 or 514-762-2020 ext. 5773 • Multi-Services (marketing, IT) C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie Vol 74 | No 2 2012 39 ABSTRACT
Background 5.72-22.2 mmol/l; a stroke occured post- follow-up, his best corrected visual acuity Ocular and visual problems are frequent surgery causing hemiparesis on his left at a distance improved to 6/60 in both consequences of an acquired brain side; and shunt surgery to decrease the right and left eye through the new injury (ABI). The literature suggests that swelling to the area of excision and the prescription. His cycloplegic retinoscopy many patients demonstrate a myopic optic nerves. Medications included: did not show any change in myopia or shift in refractive error after a traumatic Cartia, lisinopril, Toprol XL, prednisone, astigmatism and the disk edema was brain injury (TBI), a form of an ABI. Three Reglan, and Temodar. The patient resolved. was receiving chemotherapy to treat reported courses are suggested. Most Conclusion commonly the myopia resolves under remnants of the tumour. His last eye exam This case illustrates an unusual cycloplegic conditions, secondly the in 2004 indicated a refractive error of presentation of myopic shift post ABI. shift is transient, and least commonly the -2.50-1.25X080 in his right eye and -3.00- The patient’s condition continued to myopia increases over time. This case 0.75X080 in his left eye with visual acuity deteriorate eventually taking his life. It report, although not due to a TBI, is an of 6/7.5 in both the right and left eye. remains unclear whether the myopia and example of the least common subgroup. He presented to our clinic with an aided visual acuity of 8/100 (6/110) in both the astigmatism continued to increase or Case Report right and left eye and a left homonymous remained stable. Although, the cause of The patient, a 63 year-old male, presented hemianopsia on finger counting fields. this change is not fully understood and with a history (15 months prior to initial Cycloplegic retinoscopy revealed -6.00- needs further investigation, providing evaluation) of an excised right frontal 3.00X090 in his right eye and -6.00- appropriate optical correction did temporal lobe tumour. The history 2.00X090 in his left eye. Dilated fundus improve the patient’s quality-of-life. included dexamethasone 4mg QD pre- exam showed mild swelling of both Key words: tumours, myopia – treatment, and post-surgery which caused blood optic nerves. The patient reported blood brain injury. glucose levels to fluctuate between glucose levels of 103-140. At a one-month
Table 1: The Categories and Components of Acquired Brain Injury of pseudomyopia (58% persisted) as one of common visual problems ACQUIRED BRAIN INJURY (ABI) seen among 161 patients with head 6 EXTERNAL INSULT - TBI INTERNAL INSULT injury. 1. Closed 1. Cerebrovascular accidents (CVA) – i.e., stroke London et al. suggest that many 2. Penetrating 2. Brain surgery patients demonstrate a myopic GLASGOW COMA SCALE 3. Arteriovenous malformations (AVM) shift in refractive error after TBI 1. Severe 4. Brain tumours – malignant and benign and refer to this myopic shift as 7 2. Moderate 5. Vestibular dysfunctions “post-traumatic pseudomyopia”. 3. Mild Three reported courses have been suggested in non-presbyopic patients. Most commonly, the neurological event, there is often an problems associated with trauma to myopia resolves under cycloplegic interruption to the neurological sys- the visual system (Table 2).1, 3 Due to conditions, secondly the shift is tem which innervates the extraocular the similarities in the pathogenesis transient, and least commonly the muscles controlling eye movement of TBI and stroke, there is consider- myopia increases over time. This as well as the system that regulates able overlap in the ocular and visual case report, although not due to focusing. Neuro-optometrists have symptoms. One such visual problem a TBI, is an example of the least identified a syndrome, the post is a change in refractive error with an common subgroup. trauma vision syndrome (PTVS), increase in myopia. Kowal identi-
which includes visual symptoms and fied a 19 per cent prevalence rate
40 Vol 74 | No 2 2012 C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie Table 2: Visual Sequelae and Symptoms of ABI
1. Visual field losses Central, congruous, and incongruous homonymous hemianopias and quadrantanopias, altitudinal, neglect 2. Eye movement dysfunctions Fixation, pursuit, saccade, nystagmus 3. Ocular muscle dysfunctions Strabismus, anisocoria, lagophthalmos, ptosis 4. Binocular dysfunctions Exophoria, convergence insufficiency, vertical phorias, fusional instabilities 5. Accommodative dysfunctions Amplitude, flexibility, sustainability 6. Perceptual dysfunctions Contrast sensitivity, colour vision, body image, left-right discrimination, spatial relationships, agnosias, “subjective visual disturbances.” e.g., wavy and shimmering vision, photosensitivity
7. Visually-involved vestibular dysfunctions Vertigo, loss of balance, increased sensitivity to visual motion
8. Change of refractive error Increased myopia 9. Symptoms Diplopia, blurred near vision, perceived movement of print, asthenopia, headaches, photophobia
It is interesting to note that the most likely representing a combina- Diagnostic data progression of myopia has been tion of therapeutic effect and recur- The patient presented to our clinic reported in the younger population rent/residual tumor. Post-excision wearing a progressive lens and but is not the case in those over herniation of the brain through the had a chief complaint of blurred 40 years-of-age. Although the craniectomy site occurred with the vision in both eyes when viewing underlying mechanism is unclear, tumor extending into the splenium at a distance and near. No diplo- there is no known method to of the corpus callosum and the pia was reported. The following effectively halt the progression contralateral hemisphere. is a summary of our examination 2 of the myopia over time. Additional history included findings. His visual acuity, mea- dexamethasone 4mg QD pre and sured through his habitual cor- Case Report post surgery which caused blood rection of -2.50-1.25×080 in his History glucose levels to fluctuate between right eye and -3.00-0.75×080 in his 5.72-22.2 mmol/l. Medications left eye with a near vision addi- The patient, a 63 year-old male, included: Cartia, lisinopril, tion of +2.50 in both eyes, was presented with a history of a right Toprol XL, prednisone, Reglan, 8/100 (6/110) in both the right temporal lobe tumour excised 15 and Temodar. The patient was and left eye. His pupils were 5mm months prior to initial examination. receiving radiation and chemo- in both eyes and equally reactive A cerebral vascular accident (CVA therapy treatments to treat rem- and responsive to light however, or stroke) occurred post-surgically, nants of the tumour. His last eye a relative afferent pupillary defect causing hemiparesis to his left side. exam in 2004, prior to the tumour, was present in the right eye. Cover The patient is currently wheelchair indicated a refractive error of test revealed a constant alternating bound. A right frontal shunt catheter -2.50-1.25×080 in his right eye and esotropia of 15 prism diopters at was placed in the right lateral ventri- -3.00-0.75×080 in his left eye with distance and 18 prism diopters at cle secondary to hydrocephalus. Ven- visual acuity of 6/7.5 in both the near with a left hypotropia. A head triculomegaly was also reported on a right and left eye at distance. Near tilt to the left and lack of general CT scan. An MRI revealed extensive visual acuity was not measured. head control was noted as well as abnormal changes throughout the Ocular health was unremarkable. a bulge on the right temporal side right frontal and temporal lobes
C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie Vol 74 | No 2 2012 41 of his head. Confrontation visual distance viewing. He was pre- or astigmatism. The disk edema had fields revealed a left homonymous scribed a separate pair of glasses resolved in both eyes. hemianopsia. No spatial neglect for reading (-2.75-2.50×090 in was seen. Dry retinoscopy mani- both his right eye and left eye), Assessment fested less astigmatism in both rather than using a progressive or The patient’s wife reported that eyes than his habitual correction: bifocal lens due to his poor head since he began wearing his distance -2.50-0.50×180 in his right eye control. He was scheduled for prescription, he was able to see and -2.50-0.50×180 in his left eye. shunt placement surgery to resolve his family members much more Cycloplegic retinoscopy, however, the hydrocephalus. Since the clearly. His lateral balance had im- revealed a higher amount of both patient was continuing with radia- proved during physiotherapy and myopia and astigmatism in both tion, chemotherapy, as well as the he had been holding his head up- eyes: -5.25-2.50×090 in his right aggressive medical management right on his own. He was also able eye and -5.50-2.50×090 in his left of the tumour remnants, it would to read his favourite magazines. eye. Anterior segment evaluation be unclear whether the myopia Hence, a change in prescription was unremarkable with the and astigmatism will continue to and prescribing two separate pairs exception of mild blepharitis, increase or remain stable. The of glasses improved his quality-of- meibomianitis, and mild cortical patient was scheduled to return life. Visual acuity and visual func- changes in both eyes. Posterior to our clinic after wearing his new tion had both been improved such segment showed mild swelling prescription for one month, after that the patient was now able to of the optic nerves in the left eye which he would be re-evaluated read magazines, watch television, more than right. periodically over the following and interact with his grandchildren year. Vision therapy and low vision without blurry vision. Assessment rehabilitation were discussed and Management The patient presented with an would be addressed at a follow-up increased bilateral shift in myopia visit. Our goal was to continue to and astigmatism possibly due to monitor the patient periodically the surgical removal of the tu- Follow up evaluation throughout the year. His condition mour, subsequent stroke, and/or (One month after initial evaluation) continued to deteriorate causing the medical intervention (i.e., ra- During the follow-up examination, him to lose speech, thus making diation and chemotherapy to treat he was much more alert during communication more difficult. As the tumour remnants). He also had than at his initial examination. changes in his condition occurred, a left homonymous hemianopsia Blood sugar had been monitored there may have been secondary with an associated left hemipare- twice daily over the last month and changes in his refractive error but sis causing a loss of mobility, as was reported to be in the range of due to his illness and frequent well as a relative afferent pupillary 5.72-22.2 mmol/l. The patient’s best visits to the hospital, follow-up defect in the right eye secondary corrected visual acuity at distance in our clinic was minimal. He was to optic nerve head swelling (right improved to 6/60 with each eye advised to continue using both pair eye 42 Vol 74 | No 2 2012 C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie unstable. The patient passed away A. Total Blindness, right eye in late November shortly after B. Nasal hemianopsia of right eye American Thanksgiving. C. Left homonymous hemianopsia a. with macular splitting Conclusion b. with either macular splitting or macular sparing This case illustrates an unusual D. Bitemporal (heteronymous) case of myopic shift post-ABI. hemianopsia Certain findings need to be con- sidered for the increase in myopia. Firstly, the patient was on dexa- methasone 4mg QD pre-and post- surgery causing blood glucose lev- els to fluctuate between 5.72-22.2 mmol/l. When he was seen for his eye evaluation, he was on predni- sone. Effects of long-term use of systemic steroids include: increased blood sugar levels, blurred vision, elevated intraocular pressure with possible development of glauco- Figure 1 : Visual field defects ma, optic nerve damage, and pos- terior subcapsular cataract.8 Extra glucose in the hyperglycemic state baseline once the corticosteroid associated left hemi-paresis and causes an accumulation of sorbitol dosage was reduced. no spatial neglect. Homonymous which disturbs the osmotic balance A second possible cause for the hemianopias appear with lesions 10 of the lens and plays a key role in myopic shift would be an increase in in the retrochiasmatic pathways. cataract formation. Once sorbitol axial length. Due to the patient’s de- The more posterior the lesion is is in the lens, it draws water into teriorating condition, an A-scan was located in the optic pathways, the 11 the cells leading to swelling, and not done to rule out this possibility, greater the congruity of defect. structural and chemical changes. however, the MRI did not show any A homonymous hemianopsia can This process may influence the remnant tumours in or around the be seen with either macular sparing refractive power of the lens, result- orbit. In retrospect, it is unlikely that where the lesion occurs beyond ing in transient increases in myopia there was a tumour compressing the lateral geniculate body or or cataracts because of the osmot- each eye by the same amount result- macular splitting where the lesion ic swelling of cortical fibres.9 ing in an equal myopic shift in both can either be before or after the 12 In this patient’s case, his uncon- eyes. Similarly, there was asymmetric lateral geniculate body (Figure 1). trolled blood glucose level along optic nerve head swelling (right As confrontational, not automated, with his steroid induced diabetes, eye C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie Vol 74 | No 2 2012 43 left hemiparesis, is it probable the oldest reported in the literature. In pathway from the lateral suprasyl- lesion was present along the right our patient’s case, the triad of AS vian cortex bilaterally to the ocular optic tract and cerebral peduncle. was present and most likely due to motor nuclei.5 Stimulation of this The MRI showed atrophy to the an organic cause rather than func- area also causes convergence and cerebral peduncle suggestive of tional due to his reduced accommo- miosis, but accommodation may wallerian degeneration or axonal dative range. be selectively activated.5 They also degeneration from the insults to The parasympathetic division of mention that although overactive the right cerebral hemisphere. the oculomotor nerve is responsible accommodation appears to be un- Another possible cause for for pupillary constriction and accom- common in brain lesions, accom- the myopic shift may be due to modation.15 London et al. have pos- modative paresis is not. Among post-traumatic pseudomyopia. tulated a shift in myopia secondary patients with lesions of the dorsal Pseudomyopia, an intermittent to an irritative lesion that affects the midbrain, accommodative paresis and temporary shift in the refrac- accommodative portion of the para- may alternate with accommoda- tive error towards myopia, differs sympathetic third nerve subnucleus, tive spasm6 suggesting a linkage from true myopia as it develops resulting in ciliary body contraction, in accommodative excess and over time and is the result of an or possibly disinhibition of brain- deficiency in brainstem damage. accommodative spasm (AS) due stem centres.7 Chan and Trobe,16 in These spasms are more common to prolonged near work. AS is a a retrospective review of six patients in younger patients and can still be triad of pseudomyopia, esodevia- with post-traumatic pseudomyopia, present after six years of topical tion, and pupillary constriction. suggested that although it is rare, AS atropine treatment.11 It is possible It can either be organic in origin may present without other compo- that the patient may have had an through the stimulation of the nents of the near reflex. The AS accommodative paresis resulting in parasympathetic nervous system; may result from severe brainstem his myopic shift. or functional, through eye strain or injury in young adults. Bohlmann et The dysfunction and stress in fatigue of ocular systems.13 Voon al. reported a patient with significant the central and autonomic ner- et al. described a case in which AS pseudomyopia nine years after her vous systems causes imbalances was associated with dorsal mid- initial trauma. The resultant AS was in refractive and accommodative brain syndrome with a blocked suggested to be due to a possible states of function as well as in ocu- ventriculo-peritoneal shunt insert- mesencephalic lesion in the upper lar alignment. Leslie suggests that ed for aqueductal stenosis. In this brainstem following trauma to the there is a pattern of PTVS with a unusual case of pseudomyopia, an basilar skull. The authors felt it was moderate degree of myopia, and exodeviation was present without important to recognize that some a moderate-to-severe degree of pupil constriction.14 patients may experience a prolonged accommodative insufficiency. It is Usually AS presents in young course of AS after significant head not accommodative spasm in the adults who have active accommoda- trauma and proposed that such cases true sense, since there is excessive tion or experience a change in their may not be the result of a functional focus at distance but insufficient visual requirements such as prepar- cause.17 The patient’s MRI showed focus at near. In Leslie’s experi- ing for an exam, or a change in occu- an abnormal signal extending on the ence, the cases studied are all pation. Even when associated with right side down into the brainstem. long-term, chronic problems. organic disease, the patients reported One can postulate that in our The majority of these chronic in the literature have been under patient’s case, the accommodative cases studied show stable myopia 57 years-of-age. Knapp et al. report- abnormalities could be caused by and accommodative function over ed a patient that developed spasms abnormalities of the midbrain or time. The mechanism behind this of near reflex at the age of 86 years. the oculomotor nerve.18 In cats, postulation is that brain trauma She is to the authors’ knowledge the accommodation is mediated by a can disrupt a person's ability to 44 Vol 74 | No 2 2012 C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie access learned z-axis sensorimo- improved the patient’s quality-of- aspx?article=&loc=articles\2001\ tor control of accommodation life and should not be overlooked june\0601086.htm in visual space. The system loses when managing patients with ABI. 10. Huber A. Homonymous Hemianopsia. Neurto-opthalmology 1993; 12:351-266. its ability to know and respond 11. Brazis P. W., Masdeu J.C., and Biller Jose. to changes in task distance. The References Localization in Clinical Neurology 4th accommodation system essentially 1. Optometrists Network. Problems ed. Philadelphia: Lippincott Williams & localizes at its resting tonus (i.e., Associated with Acquired Neurological Wilkins, 2001. dark focus). Vision testing reveals Events. Allen H. Cohen. C a N adiaN J ourN al of o ptometry | r e V ue C a N adieNNe d ’ optométrie Vol 74 | No 2 2012 45