Fusion ability lost and regained in visual adults.

The case reports are given of two adult patients who lost all fusion ability and had the signs and symptoms of central fusion disruption and intractable diplopia. Both patients suffered binocular sensory deprivation for several years caused by a combination of a traumatic cataract and uncorrected unilateral aphakia. One patient had a posterior chamber intraocular lens inserted to correct the aphakia and the other patient had a contact lens. Aniseikonia was not appreciated by either patient and did not appear to contribute to the fusion problem. Adjustable strabismus surgery, in both patients, and prism glasses, in one, enabled approximate superimposition of the visual axes. After several months, both patients began to develop some fusion with small amplitudes and the vertical bobbing typical of central fusion disruption disappeared.