Unilateral congenital cataract: binocular status after treatment.

We describe the binocular status of four patients, aged 5, 6, 10, and 13 years, who had a unilateral congenital cataract removed in the first few months of life. A contact lens had been fitted in all cases and was worn continuously. The normal eye was occluded for approximately 90% of the waking day until at least the age of 4 years. Two patients developed an esotropia and two an exotropia. Best-corrected visual acuity is 20/40 or better in both the aphakic and the normal eye. The patients' binocular status was assessed with a full eye examination, tests for fusion in free space with prism neutralization, tests for stereopsis, and examination on the Clement Clarke synoptophore. All patients showed simultaneous perception but no real fusion, resulting in diplopia. A vertical bobbing effect was noted at the angle of neutralization similar to that reported by us in cases of central fusion disruption.