Surgical outcomes of bilateral medial rectus recession in cases of acute acquired comitant esotropia.

BACKGROUND: Acute Acquired Comitant Esotropia (AACE) is a form of acquired esotropia that occurs in patients without significant hyperopic refractive error. This study aims to investigate the outcomes of bilateral medial rectus muscle (BMR) recession in patients diagnosed with AACE at our strabismus referral center. METHODS: Surgical profiles of all AACE cases who underwent BMR recession from 2015 to 2024 were recruited. Ocular deviation was measured using the base-out breakpoint method during alternate prism cover testing. Postoperative outcomes were evaluated six weeks (short-term) and six months to five years after the surgery (long-term). Cases that experienced postoperative diplopia or a horizontal deviation greater than eight Prism Diopters (PD) were classified as surgical failures. RESULTS: This study involved 118 cases of AACE, with an average age of 7.8 years. The average visual acuity was 0.07 ± 0.09 LogMAR in the right eye and 0.08 ± 0.13 LogMAR in the left eye. The spherical equivalent of cycloplegic refraction was + 0.60 ± 1.57 diopters (D) and + 0.65 ± 1.54 D in the right and left eye, respectively. Average esotropia was 43.36 PD in near fixation and 42.61 PD in distant fixation. Bilateral medial rectus recession 4 to 7 mm (based on Park's standard table) was performed. The overall short-term and long-term success rates were 90.7% and 81.2%, respectively. Surgical failure was more frequently observed in younger patients and those without diplopia (p-values: 0.018 and 0.003). Preoperative visual acuity, refractive error, and angle of esotropia did not affect the surgical outcome. CONCLUSION: BMR recession was an appropriate surgical option for treating AACE cases. The base-out breakpoint method proved effective for preoperative measurement of esotropia in these cases.