Photorefractive Keratectomy Outcomes In Myopic Patients With Thick Corneas: A Retrospective Analysis Of 41,478 Eyes
Published 2025 - 43rd Congress of the ESCRS
Reference: FP30.06 | Type: Free paper | DOI: 10.82333/64ms-jc81
Authors: Carlos Augusto Ferraresi Sampaio* 1 , Dillan Cunha Amaral 2 , Carolina Valentim 3 , Laura Cheidde 4 , Lidia Cheidde 5 , Jaime Guedes 6 , Ricardo Louzada 2
1Pontifical Catholic University of Paraná,Londrina,Brazil, 2Federal University of Rio de Janeiro,Rio de Janeiro,Brazil, 3Department of Ophthalmology and Visual Sciences,University of Louisville,Louisville,United States, 4City University of São Paulo,São Paulo,Brazil, 5Pontifical Catholic University of São Paulo,Sorocaba,Brazil, 6Glaucoma Research Center,Wills Eye Hospital,Philadelphia,United States
Purpose
To evaluate the outcomes of Photorefractive Keratectomy (PRK) in myopic patients with very thick corneas (>600 microns) compared to those with normal corneal thickness (500–600 microns). While PRK is widely performed for myopic correction, the impact of corneal thickness on postoperative outcomes remains debated. Some concerns exist regarding suboptimal healing in thicker corneas, potentially affecting visual recovery and long-term stability. This study aims to clarify whether thick corneas influence safety, efficacy, and retreatment rates after PRK.
Setting
A retrospective analysis of PRK procedures performed at Care-Vision Laser Centers, a high-volume refractive surgery clinic in Tel Aviv, Israel, between January 2010 and June 2024.
Methods
This retrospective cohort study included patients aged 20 to 40 years with myopia up to -12.0 diopters. Eyes were categorized based on corneal thickness: normal (500–600 microns) and thick (>600 microns). Preoperative, intraoperative, and postoperative parameters, including corrected and uncorrected distance visual acuity (UDVA), safety and efficacy, and retreatment and ectasia rates, were compared between groups. Statistical methods were applied to account for possible confounders.
Results
A total of 41,478 eyes were included, with 1,001 in the thick cornea group and 40,477 in the normal thickness group. Preoperative mean corneal thickness was 615.1 ± 13.7 μm in the thick cornea group and 538.0 ± 24.3 μm in the normal thickness group. No significant differences were found in postoperative UDVA (0.9495 ± 0.1304 vs. 0.9473 ± 0.1464) or spherical equivalent (0.0311 ± 0.3463 vs. 0.0215 ± 0.3789 D). Safety (1.023 ± 0.1129 vs. 1.023 ± 0.1183) and efficacy (1.007 ± 0.1496 vs. 1.013 ± 0.1353) indices were comparable. Retreatment was higher in the thick cornea group (0.90% vs. 0.38%, p = 0.0552). Ectasia occurred in 10 eyes (0.025%) of the normal thickness group but none in the thick cornea group
Conclusions
PRK in myopic patients with thick corneas is safe and effective. No significant differences in safety or efficacy were found compared to patients with normal corneal thickness. The slightly higher retreatment rate in the thick cornea group was not statistically significant. No cases of ectasia were reported in thick corneas, though the true risk remains uncertain due to limited cases.