To compare the surgical outcomes of functional equator-considering and Parks' methods in infantile esotropia and partially accommodative esotropia.

The medical records of 96 patients with infantile esotropia and partially accommodative esotropia who underwent bilateral medial rectus muscle recession by functional equator-considering and Parks' methods were reviewed retrospectively. The surgery success rate at 1 month, 3 months, 6 months and 12 months was compared by the deviation angle measurement.

Overall success rates were not statistically different between the 2 groups. Additionally, there were no differences in surgical success rate of functional equator-considering and Parks' methods in infantile esotropia and partially accommodative esotropia. When the patients were divided into 2 groups based on 40 PD, no significant difference in success rate between the 2 groups was observed. When patients were divided into 2 groups based on 22 mm of axial length, there was no statistical difference observed. Postoperative overcorrection was 2 (4%) in the functional equator group and 3 (6.5%) in Parks' method group and postoperative undercorrection was 9 (18%, 19.6%) in each group. The incidence of undercorrection in the Parks' method group was significantly higher in the greater than 22 mm axial length group (7, 35.0%) than in the less than 22 mm group (2, 7.7%) ( p = 0.029).

There was no statistically significant difference in surgical success rate between the functional equator and Parks' methods in infantile esotropia and partially accommodative esotropia.