To determine changes in streoacuity in anisometropic myopic eyes after photorefractive keratectomy (PRK).

This quasi-experimental clinical trial was performed in myopic patients with at least 1 D of in anisometropia spherical, astigmatic or spherical equivalent who underwent photorefractive keratectomy (PRK) using the Technolas 217 Z excimer laser machine. Changes in streoacuity were evaluated. TNO and butterfly stereoacuity tests before PRK and at 2 weeks, 1 month and 3 months after PRK.

Overall, 98 eyes of 49 patients (71.4% male and 28.6% female subjects) with mean age of 285.5 years and mean myopia of -3.321.74D and mean astigmatism of 1.31.3 D were enrolled in study. Preoperative mean stereoacuity values were 102103.44 sec/arc and 56.841 sec/arc by TNO and butterfly stereoacuity tests which changed to 90110.52 sec/arc (P=0.009) ،and 56.541.3 sec/arc (P=0.80) respectively 3 months after PRK. Total proportion of improvement in stereoacuity values was 10.2% and 6.12% by TNO and Butterfly Stereoacuity tests respectively.

Stereoacuity improves after photorefractive keratectomy in anisometropic myopic patients. This improvement is more significant with TNO test than the Butterfly Stereoacuity test.