Development of anisometropia in patients after surgery for esotropia

Anisometropia is reported to increase with age; however, the relationship between the development of anisometropia and binocular vision has not been determined. The purpose of this study was to determine the relationship between anisometropia and binocular vision after esotropia (ET) surgery.

The medical records of 51 consecutive patients with ET who had undergone ET surgery were studied. Patients with amblyopia or anisometropia ≥2 diopters (D) before surgery were excluded. The average age of the patients at the time of surgery was 4.5 ± 3.7 years, and the average postoperative period was 5.0 ± 2.2 years. The refractive errors (spherical equivalent) in both eyes were measured preoperatively and postoperatively. Binocular visual function was evaluated with a modified Worth-4 dot test.

At the final visit, average anisometropia was 0.98 ± 1.30 D, which was significantly greater than the preoperative value of 0.36 ± 0.46 D (P < 0.001). Anisometropia ≥2 D was observed in ten patients (23%) postoperatively. One patient was able to fuse a target of ≥2° (10%) in the anisometropia ≥2 D group, significantly fewer than the 13 patients (32%) in the anisometropia <2.0 D group (P = 0.02).

Anisometropia may develop in patients with poor sensory fusion after surgery for esotropia.