Management of Consecutive Exotropia and Refractive Amblyopia Confounded by Homonymous Hemianopsia Morgan Ollinger, OD, Pediatric and Binocular Vision Resident

Background Case Data Refractive amblyopia and strabismus are conditions that are A 22 year old female with cerebral palsy presented for a sensorimotor evaluation often treated with vision therapy in order to restore visual with complaints of eyestrain and blur, present for a year. She reported that she had function. These therapies, however, rely partially on patients strabismus surgery at a young age. Examination findings are summarized in Table 1. having functional peripheral fusion, and can be complicated by The patient denied headaches, dizziness, and other neurological symptoms. prior surgery. With the presence of significant visual field defects on top of that, binocular therapy becomes more difficult. This case outlines the management of a patient with refractive amblyopia, consecutive exotropia, and a homonymous hemianopsia, who is interested in improving visual function.

Exam OD OS Findings Figure 1: Hess-Lancaster Screen Results (OS fixating in green, OD fixating in red) Damp +6.00 -2.25 x 173 +8.50 -3.00 x 020 Refraction 20/25 20/40 Discussion With BCVA When a homonymous hemianopsia is present in binocular vision Sluggish, mild dysfunction, it complicates prognosis. The field loss worsens the Pupils Sluggish, no RAPD RAPD likelihood of achieving binocular vision, as peripheral fusion is significantly impacted. Yoked prism can be useful in improving visual 1 Distance CT CAXT, 8Δ with OD CAXT, 8Δ with OS function for hemianopic patients , and may allow for more effective therapy. In this case, the patient reported subjective improvements in (primary gaze) neutralized neutralized orientation, gait, and acuity with yoked prism. Figure 2: 30-2 Visual Fields When the patient does pursue therapy, it is important to manage patient Near CT CAXT, 10Δ with OD CAXT, 18Δ with OS expectations, and to have realistic outcomes. While improvements in (primary gaze) neutralized neutralized Management Options ocular motility and visual processing are likely, resolution of the As the patient was new to our clinic, imaging was ordered before any other strabismus has a poor prognosis. Improvements in visual acuity are Comitancy See Figure 1 management was pursued, in order to rule out serious causes of hemianopsia, as it possible as well, as homonymous hemianopsias typically do not affect central acuity2. It is worth noting, however, that lesions may be present Full range of Full range of had not been noted previously. Imaging showed defects consistent with cerebral EOMs palsy. elsewhere in the visual pathway that are affecting central acuity. The motion motion Yoked prism was trialed with this patient. She subjectively preferred 4Δ base out over presence of an RAPD, as well as nerve head pallor, raises this question. Visual Fields See Figure 2 the right eye, and 10Δ base in over the left eye. This was trialed with Fresnel prisms, Another key consideration was evaluation of the visual field defect. Neurological imaging was ordered, as no previous documentation Latent and was eventually ground into lenses for full time wear. Absent Low amplitude Vision therapy was discussed with this patient. She is interested and motivated to indicated that imaging had ever been done to investigate the Nystagmus pursue vision therapy to improve oculomotor function an visual processing. Due to hemianopsia. Optic Nerve Mild temporal scheduling conflicts, therapy has not been initiated. Despite a plethora of complicating factors, it is important to consider Mild pallor Head pallor patient symptoms and concerns, and to manage each of these as References efficiently as possible. In this case, the patient experienced a reduction in Table 1: Summary of Exam Findings 1. Bansal, S., Han, E., & Ciuffreda, K. J. (2014). Use of yoked prisms in patients with symptoms with the use of yoked prisms. Further reduction of symptoms acquired brain injury: A retrospective analysis. Brain Injury, 28(11), 1441-1446. will likely be achieved with vision therapy. 2. Goodwin, D. (2014). Homonymous hemianopia: challenges and solutions. Clinical Contact Information Ophthalmology, 1919. Morgan Ollinger, OD [email protected]