Refractive surgery and strabismus

Abstract

Aim: To evaluate the orthoptic outcome of patients with a pre-existing ocular motility defect who presented for Lasik refractive surgery. Method: The case notes were reviewed of 59 patients who had presented to two centres for Lasik refractive surgery and were judged to be at risk of post­operative symptoms because of a pre-existing ocular motility defect. All patients had undergone a com­prehensive orthoptic assessment. Factors examined in the analysis were the type of refractive error, the type of deviation, change in binocular status, change in the angle of deviation, and incidence of symptoms/diplopia after refractive surgery. Results: Forty-four patients were considered suitable for refractive surgery. Of these, 39 proceeded to surgery; data were incomplete for 12 cases, leaving 27 cases for analysis. No patient experienced diplopia or a change in binocular status after refractive surgery. Five patients with an accommodative-type esotropia had a reduction in the angle of deviation of between 9Δ and 20Δ. There was a small reduction in angle of 5Δ to 6Δ in 3 patients with exo deviations and a reduction of 12Δ base-out and 15Δ base-in for 2 patients with myopic anisometropia. Conclusion: Full orthoptic assessment of binocular status prior to refractive surgery is essential for patients with a pre-existing ocular motility defect, in order to identify those who are at risk of post­operative symptoms/diplopia and provide advice on the possible consequences of proceeding with the surgery.