Clinical Features Of Patients Who Needed More Than One-Time Photorefractive Keratectomy (Prk), A Retrospective Cohort Study
Published 2026 - 44th Congress of the ESCRS
Reference: POREF235 | Type: Free paper | DOI: 10.82333/8wjt-w989
Authors: Dr Yasir Adil Shakor* 1 , Dr Hesam Hashemian 1 , Dr Ulfat Anjum 1 , Mr Reza Yousefi 1
1School of Rehabilitation, Tehran University of Medical Sciences,Translational Ophthalmology Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, ,Tehran,Iran, Islamic Republic Of
Purpose
To evaluate the clinical features of patients who had undergone photorefractive keratectomy (PRK) more than once. Identifying these pre-operative parameters can help in assessing patients at higher risk of repeat PRK.
Setting
A single-center study conducted at Farabi Eye Hospital, Iran.
Methods
In this historical cohort study, the data were obtained from electronic records, refined, and divided into two groups based on PRK outcome: cases that underwent a second round of PRK and controls that underwent PRK only once. Only patients with at least 12 months postoperative follow-up were included. The baseline preoperative data, including subjective & objective refraction, spherical equivalent, anterior and posterior keratometry, and corneal pachymetry at the apex & thinnest location, were collected. The PRK surgery was performed using Schwind Amaris 1050 RS by Sirius CSO, and the anterior segment measurements were taken using Pentacam® HR.
Results
Among 48 patients (17 second-PRK, 31 single-PRK), significant differences were observed between groups:
Refraction: Case group had less myopia and higher astigmatism than controls in both subjective (sphere 0.07 vs. -3.17; astigmatism -2.06 vs. -0.90; SE -0.96 vs. -3.62) and objective measures (sphere 0.57 vs. -2.75; astigmatism -1.97 vs. -0.91; SE -0.41 vs. -3.20; all P≤.003).
Corneal parameters: Case group showed flatter anterior keratometry (K1 42.75 vs. 43.93) and higher anterior corneal astigmatism (1.82 vs. 1.03, P<.05).
Patients requiring a second PRK had less myopia, more astigmatism, and flatter corneas than those treated successfully with a single PRK.
Conclusions
Patients who needed more than one PRK surgery had significantly lower sphere and SE, greater astigmatism, lower anterior flat-K, decreased corneal thickness, and greater anterior corneal astigmatism than patients who needed only one PRK surgery.