Determination of Stereo-Acuity Changes after Trans-epithelial Photorefractive Keratectomy in Anisometropic Myopia

To determine the changes of setreoacuity after trans-epithelial photorefractive keratectomy (T-PRK) procedure in anisometropic myopic eyes. Methods: In this quasi-experimental study performed on myopic patients with at least 1 D of anisometropia who underwent T-PRK with mitomycin-C (MMC) for treatment of myopia using Amaris 500-Hz excimer laser (SCHWIND eye-tech solutions GmbH, Germany). Stereoacuity changes measured by TNO and butterfly stereoacuity test before T-PRK and 1, 3 and 6 months postoperatively. Results: 108 eyes of 54 patients (44.4% male and 55.6% female) with mean age of 26±4 years and mean myopia of -4.24±1.22 D and mean astigmatism of 1.1±0.75 D were enrolled. The preoperative mean stereoacuity values 99±5.44 sec/arc and 52.6±3.5 sec/arc by TNO and Butterfly Stereoacuity test changed to 85±4.56 sec/arc(P<0.05), and 46.5±1.3 sec/arc (P<0.05) respectively at 6 months after T-PRK. Total proportion of improvement in stereoacuity values was 14.1% and 11.5% by TNO and Butterfly Stereoacuity tests respectively. Conclusion: Stereoacuity improves after T-PRK in anisometropic myopic patients. TNO test can detect this improvement better than Butterfly test.