Refractive, Aberrometric And Epithelial Outcomes Between Prk Versus T-Prk, Randomized Clinical Trial.

Evaluate the aberrometric, refractive and epithelial outcomes of photorefractive keratectomy (PRK) treatment in one eye compared to Trans-epithelial PRK (t-PRK) in the fellow eye in adults diagnosed as having myopia and /or astigmatism.

Randomized clinical trial of normal eyes who undergo traditional alcohol-assisted PRK in the first eye and t-PRK correction in the fellow eye at Oftalmosalud, Lima, Peru, between September 2020 and January 2021.This study was approved by the Institutional Review Board of the Institution. Informed consent was obtained after the hospital research review board approved the study protocol. The study conformed to the tenets of the Declaration of Helsinki (1975), as revised in Edinburgh 2000.

30 eyes (30 consecutive patients) of the alcohol-assisted PRK group and 30 eyes (30 consecutive patients) of the T-PRK group. Examination included uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), slit-lamp examination, corneal tomography (Pentacam, MS39), all variables were measured at basal time, 1 week, 1, 3 and 6 months.The first eye procedure was randomly assigned for each group by a random number generator, in the second eye the other procedure was performed. All treatments were performed by the same surgeon using the same excimer laser (Schwind, Amaris 1050RS).Procedure was not blinded for technical reasons.

The complete follow-up was performed in 18 eyes of 18 patients. Regarding PRK group spherical aberration increased over time significantly (p= 9e-7). Epithelial evaluation showed an increase in thickness at the first week that gradually decreased until 6 months. Although all the quadrants showed an increase in epithelial thickness the lower quadrants showed important increases in last exam (p=2e-2). Regards T-PRK group; spherical aberration shows a decreased in the first weeks and an increased over the last measures (p=7e-9). Epithelial evaluation showed an increase in all quadrants during the first week that remained thickened during the entire follow-up (p=4e-7). No differences were found between treatments.

Although epithelial growth greater than baseline was generated in both groups, in PRK treatment it was more evident in the lower quadrants and in transprk it was diffuse. Spherical aberrations increased at follow-up time in both groups. Both procedures were comparables, safe and generate success in visual acuity from the first week of follow-up.