Non-organic vision loss

A 22-year-old female presented after she fell and hit her head on the car door, with decreased vision in the right eye (OD). Past medical history was significant for ventriculoperitoneal shunt (VPS) and for pseudotumor cerebri diagnosed several years prior. In addition to the visual loss OD, she complained of four episodes, lasting approximately 1 minute, of shaking in all four extremities, headache, right leg sensory abnormalities, and left eye (OS) pain. The remainder of the past medical, surgical, social, and family history was non-contributory. On examination, the patient was alert and oriented and there was no focal neurological defect. Best-corrected visual acuity was 20/200 OD and 20/20 OS. The pupils measured 5 mm in the dark and 3 mm in the light and there was no relative afferent pupillary defect (RAPD). Extraocular motility, intraocular pressure measurements, anterior segment, and funduscopic exams were normal in both eyes (OU). There was no papilledema or optic atrophy seen OU. Automated and confrontation visual field testing showed a constriction to a 5-degree island OU. Saccade testing showed normal and accurate saccades into the supposedly blind visual field OU. The 5-degree island did not expand (Fig. 20.1) at 1 m and 2 m testing to confrontation OU, consistent with a tunnel visual field. The patient had normal stereoacuity testing at 40 seconds of arc, consistent with 20/20 visual acuity OU. The patient reported seeing two vertically displaced 20/25 Snellen letter “e”s after a four base-down vertical prism was placed over the normal seeing left eye. All of these responses were considered evidence for non-organic overlay. The patient had been admitted to the neurology service. MRI of the brain showed the shunt in good position with no ventriculomegaly. Electroencephalography showed no epileptiform activity but multiple pseudoseizures were noted during testing, A final discharge diagnosis of non-organic overlay was made. The patient was reassured and on follow-up exam six weeks later her vision had returned to normal 20/20 OU.