Inadvertent scleral perforation after strabismus surgery: incidence and association with refractive error

Background: Inadvertent scleral perforation is a rare but serious complication of extraocular muscle surgery for strabismus. We evaluated the incidence of unwanted scleral penetration after strabismus surgery and its association with refractive error. Methods: This cross-sectional noncomparative case series comprised 453 eyes from 236 patients who underwent strabismus surgery. After dilation, each patient had fundus examination using indirect binocular ophthalmoscope. Chorioretinal scars around the suture area, which presumed the previous scleral perforation, were detected. We assessed whether the presence of these scars was related to the degree of preoperative refractive error. Results: Mean postoperative follow-up was 52.44 (SD 30.07) months. Overall incidence of inadvertent penetration of the sclera was 1.77%. A total of 8 eyes (6 patients) showed chorioretinal scars, and all were myopic. Of these, 3 eyes were classified as mild myopia, 3 as moderate myopia, and the other 2 as severe myopia. The relationship between inadvertent scleral penetration and degrees of refractive error was weak but statistically significant (p = 0.001). Interpretation: Inadvertent scleral perforation after strabismus surgery seems to be associated with myopic refractive error.