Case Report: Gross Convergence Therapy for the Treatment of Sensory Exotropia in a Patient with Severe Vision Loss

Introduction Sensory strabismus results from a disruption in sensory fusion because of significant vision loss in one or both eyes. When restoration of fusion is not possible, treatment is typically limited to extraocular muscle surgery for improved eye alignment. However, the prognosis for long-term alignment following surgery is usually poor because the vision loss precludes fusion. We report on an adult with long-standing sensory exotropia treated solely with gross convergence therapy, successfully achieving her goal of cosmetically aligned eyes. Case Report A 24-year-old female presented with sensory exotropia secondary to bilateral vision loss from cone-rod dystrophy. Her goal was to improve the cosmetic appearance of her eyes for photographs and certain social- and work-related situations without undergoing strabismus surgery. Examination revealed a constant left exotropia of 30 to 35∆ at distance and near and paradoxical anomalous correspondence type 1. Despite the poor prognosis for achieving normal binocular vision because of poor visual acuity (20/250 and 20/320) and lack of sensory fusion potential, a trial period of vision therapy focused solely on gross convergence training and using convergence-related diplopia for patient feedback of eye alignment was initiated. After 3 in-office therapy sessions over 2 months, the patient could voluntarily reduce the magnitude of her exotropia, making it cosmetically unapparent for periods of up to 30 minutes. Conclusion Using a novel therapy approach, the patient could align her eyes so that her exotropia of 30∆-35∆ was not cosmetically apparent, leading to an enhanced quality of life.