Aim

To study the motility pattern, underlying mechanism, and management of patients who complained of double vision after cataract surgery.

Methods

A retrospective case note analysis of 150 patients presenting with diplopia after cataract surgery to an orthoptic clinic over a 70-month period. Information was retrieved from orthoptic, ophthalmological, and operating room records.

Results

A total of 3% of patients presenting to the orthoptic clinic had diplopia after cataract surgery. We grouped these according to the underlying mechanisms which were: (1) decompensating pre-existing strabismus (34%), (2) extraocular muscle restriction/paresis (25%), (3) refractive (8.5%), (4) concurrent onset of systemic disease (5%), (5) central fusion disruption (5%), and (6) monocular diplopia (2.5%). Twenty per cent of the patients could not be categorised with certainty. After infiltrational anaesthesia, extraocular muscle restriction/paresis was the commonest presentation, while decompensation of preexisting strabismus was commonest with topical anaesthesia.

For the 150 patients seen, prisms were the commonest form of treatment prescribed (64%) either in isolation or in combination with other treatment, including surgery (19%). Convergence and divergence insufficiency/paresis patterns were also common. A changing motility pattern was noted in some patients who had early documentation, with increasing comitance over time (spread of comitance). Partial resolution made it difficult to clearly identify the underlying mechanism in patients with late documentation.

Conclusion

Double vision is a troublesome complication of otherwise successful cataract surgery. The use of topical anaesthesia does not abolish this surgical risk.