Vision Therapy for Sensory Fusion Disruption Syndrome: Two Case Reports

215 ABSTRACT Introduction: Sensory fusion disruption syndrome (SFDS) is a rare consequence of acquired brain injury that causes diplopia even though there is bifoveal motoric alignment of the two eyes. These individuals frequently note that the images are near each other and may appear as if one image is behind the other. When a constant strabismus is present, the prism that neutralizes the strabismic angle does not eliminate the diplopia. Monocular occlusion is often the palliative treatment utilized. Two cases are presented that have successful outcomes following office-based optometric vision therapy (OVT). Case Summaries: Case 1 is a 54-year-old female with SFDS who sought relief for her diplopia of four years duration and wished to regain the ability to read for more than ten minutes at a time. An 18-visit office-based optometric vision therapy program led to improved visual function, significant symptomatic relief, and improved activities of daily living but not a complete elimination of her diplopia. Case 2 is an 11-year-old boy with SFDS, fusional vergence dysfunction and accommodative dysfunction following head injury. He gained complete recovery after a relatively short course of eight office-based OVT sessions. Discussion: These two case reports, as well as the accompanying literature review, suggest a set of guidelines for establishing an appropriate prognosis regarding OVT for SFDS. A novel test for the depth of SFDS is presented along with an original method of arranging conditions for OVT procedures that are intended to alleviate SFDS.