Visual functions and anterior ocular surface changes post trans-PRK

Abstract

Background: Corneal refractive surgery is rapidly evolving, and several surgical techniques have been developed, including transepithelial photorefractive keratectomy (trans-PRK).

Aim: To assess the impact of trans-PRK on visual acuity (VA), contrast sensitivity, spherical aberration, tear stability, corneal surface and thickness.

Setting: The study was conducted in Saudia Arabia, Al Madinah Almunwrah, Eye Specialist Center.

Methods: A quantitative, comparative, and prospective case study was conducted. Eighty-six consenting volunteers aged between 18 years and 40 years, including both genders, were enrolled in the study. Participants were grouped according to the time they presented after surgery. The Statistical Package for Social Sciences (SPSS) software version 27 (IBM Corporation) was used for descriptive and comparative data analysis by applying one-way analysis of variance (ANOVA) and paired t-tests.

Results: There was a significant increase in contrast sensitivity (P < 0.005) and VA, with the post-operative mean best corrected visual acuity (BCVA) being 0.00 Log MAR for all groups. Central corneal thickness (CCT) was significantly thinner (P = 0.000), and significant corneal flattening occurred (P < 0.005) in all study groups. Spherical aberration improved significantly only in participants returning after 1 year (P = 0.000). Tear break-up time (TBUT) remained stable in all groups and tear volume decreased significantly in groups 1 (P = 0.000) and group 3 (P = 0.013) only.

Conclusion: The trans-PRK improves VA and contrast sensitivity and causes significant thinning and flattening of the cornea. Although tear volume decreases after trans-PRK, the TBUT does not change and patients will experience improvement in spherical aberration only after 1-year post-surgery.

Contribution: The study will benefit both clinicians and patients who intend to undergo trans-PRK, by providing information on expected post-surgical outcomes.