A paired comparison study on refractive changes after strabismus surgery

Purpose To quantify refractive changes following horizontal lateral rectus recession and medial rectus resection surgery and to investigate the causes of these changes. Methods The medical records of patients who underwent unilateral horizontal lateral rectus recession and medial rectus resection for exotropia by a single surgeon over a period of 14 years were reviewed retrospectively. Using vector analysis, refractive changes in operated eyes (cases) were compared to changes in the sound eyes (controls). The main outcome measures were differences in mean change of refractive parameters and the proportion of clinically significant changes. Results A total of 31 subjects (median age, 13.6 years; interquartile range, 8.8-19.8 years) were included. A significantly higher magnitude of refractive changes was observed in the operated eyes ( P  = 0.001). In addition, the proportion of cases with clinically significant change in sphere or cylinder was significantly higher in the operated eyes compared to the sound eyes (48% vs 10% [ OR  = 2.31, P  = 0.002] and 32% vs 10% [ OR  = 5.0, P  = 0.039], resp.). Conclusions Horizontal strabismus surgery is associated with refractive changes that might be of clinical significance. Pediatric ophthalmologists should consider re-refraction 1 month postoperatively.