Surgical dose-responses of bilateral medial rectus muscle recession in acute acquired comitant esotropia compared to infantile esotropia.

Objective: To determine the surgical dose-responses of the bilateral medial rectus recession in acute acquired comitant esotropia (AACE) compared to infantile esotropia. Design: Retrospective study. Methods: The medical records of patients diagnosed with AACE and infantile esotropia who underwent bilateral medial rectus muscle recession (BMRR) were reviewed. Patient characteristics, ocular examinations and surgical data were collected. A motor success was defined as horizontal deviation within 10 prism diopters (PD) of ortho, and a sensory success was defined as no diplopia at 6 months after the surgery. Results: A total of 114 patients were included. There were 39 patients with AACE [median (Q1-Q3) age was 20 (15-25) years, 56% was female] and 75 patients with infantile esotropia [median (Q1-Q3) age was 3 (1-5) years, 56% was female]. The surgical dose-responses of BMRR in AACE at distance and near were 2.67 PD/mm (r2 = 22.8%) and 3.48 PD/mm (r2 = 32.9%), respectively. The surgical dose-responses of BMRR in infantile esotropia at distance and near were 3.91 PD/mm (r2 = 17.8%) and 4.64 PD/mm (r2 = 18.0%), respectively. Seventy-four percent of patients with AACE and 63% of patients with infantile esotropia achieved a motor success. Eighty-five percent of patients with AACE achieved a sensory success. The postoperative drift at distance and at near was not significant in both groups [AACE 0 PD (-6 to 10), p = .26 and 2 PD (-2 to 6), p = .44; infantile esotropia [8 PD (0-14), p = .12 and 4 PD (0-10), p = .22]. Conclusions: The BMRR in infantile esotropia had a larger surgical dose-response than in AACE. In both groups, the surgical dose-responses at near were greater than at distance. There was no significant postoperative drift at distance and at near in both groups.