Diplopia after strabismus surgery for adults with nondiplopic childhood-onset strabismus

Purpose: To describe frequency of postoperative diplopia after strabismus surgery in nondiplopic adults with childhood-onset strabismus and to report health-related quality-of-life (HRQOL) outcomes. Methods: We prospectively enrolled 79 adults with no diplopia in any gaze who had childhood-onset strabismus and were scheduled for strabismus surgery. Diplopia was assessed preoperatively and at 6 weeks and 1 year postoperatively using a standardized diplopia questionnaire with 5 response options in 7 gaze positions. HRQOL was assessed using the Adult Strabismus-20 (AS-20) questionnaire, with self-perception, interactions, reading function, and general function domains. Results: Constant diplopia in straight-ahead distance and reading gaze occurred in 1 patient (1% [95% CI, 0%-7%] at 6 weeks and 2% [95% CI, 0%-10%] at 1 year). Regarding the rate of any diplopia (including rarely) in any gaze, 15 of 78 patients (19%) reported diplopia at 6 weeks, of whom 13 had diplopia in straight-ahead distance gaze; 8 (10%), in reading gaze. At 1 year, 8 of 51 patients (16%) reported any diplopia (including rarely) in any gaze, of whom 7 had diplopia in straight-ahead distance gaze and 4 (8%) in reading gaze. Mean AS-20 scores improved at 1 year overall (by 32, 19, 14, and 15 points, resp., per domain) and for the 8 diplopic patients (by 21, 13, 16, and 11 points). Conclusions: In adults with nondiplopic strabismus, constant postoperative diplopia is rare, although the rate of intermittent diplopia is higher. Even when postoperative diplopia occurs, HRQOL often improves.