Persistent binocular diplopia following cataract surgery: aetiology and management.

We studied all patients referred to the orthoptic department with binocular diplopia following cataract surgery between January 1991 and June 1993. Persistence of diplopia for a minimum of 3 months after cataract surgery was required for inclusion in the study. Eighty-one patients (2% of all patients who underwent cataract surgery during this time) satisfied the entry criteria. The patients fell into two groups: non-traumatic and traumatic cataracts. Horizontal deviations were seen in 24 patients. Vertical deviations were seen in 8 patients and a combined horizontal and vertical deviation was seen in 49 patients. Fresnel prisms were used to manage the diplopia in 58 patients. Of these, 48 patients in the non-traumatic group regained binocular single vision with this prism while 10 in the traumatic group benefited. Mechanical and sensory causes are discussed.