Predictive factors for outcomes of photorefractive keratectomy in myopic eyes

To analyze the two-year visual and refractive outcomes as well as the safety, and efficacy of photorefractive keratectomy (PRK) surgery for myopia.

In this prospective cohort study, 63 eligible patients were recruited, including 45 women (71.4%) and 18 men (28.6%). Demographic characteristics along with pre- and post-operative clinical data including visual acuity, refraction, maximum ablation, spherical and cylindrical error, and residual stromal bed (RSB) were evaluated.

The mean age of the patients was 35.42±8.16y (range 22 to 55y). The mean spherical and cylindrical error before surgery were -2.23±1.58 D (range -5 to +0.25) and -1.24±0.94 D, respectively (range -3.75 to 0.00). The mean efficacy and safety of PRK surgery at 2y follow-up were 0.98±0.06 and 1.01±0.04 respectively. The lower age was significantly correlated with a higher amount of efficacy index (P<0.001, r=-0.42). Also, the lower amount of preoperative myopia and spherical equivalent (SE) were correlated with a higher safety index (P<0.001, r=-0.44; P<0.001, r=-0.46).

The two-year efficacy and safety of PRK for the treatment of low myopia is excellent. Younger age and lower amount of refractive error are correlated with higher efficacy and safety indices of the surgery.