ESCRS - FP06.06 - Photorefractive Keratectomy Outcome For Myopic Patients With Thin Corneas: A Retrospective Cohort Study

Photorefractive Keratectomy Outcome For Myopic Patients With Thin Corneas: A Retrospective Cohort Study

Published 2025 - 43rd Congress of the ESCRS

Reference: FP06.06 | Type: Free paper | DOI: 10.82333/0206-5y72

Authors: Aya Wattad* 1 , Avinoam Shye 1 , Igor kaiserman 2 , Gur Munzer 3 , Tzachi Sela 3 , Michael Mimouni 4 , Eyal Cohen 5

1Ophthalmology,Tel Aviv Sourasky Medical Center,Tel-Aviv,Israel, 2Ophthalmology,Barzilai Medical Center,Ashkelon,Israel;Ophthalmology,Care-Vision Laser Center,Tel-Aviv,Israel, 3Ophthalmology,Care-Vision Laser Center,Tel-Aviv,Israel, 4Ophthalmology,Rambam Health Care Campus,Haifa,Israel;Ophthalmology,Care-Vision Laser Center,Tel-Aviv,Israel, 5Ophthalmology,Tel Aviv Sourasky Medical Center,Tel-Aviv,Israel;Ophthalmology,Care-Vision Laser Center,Tel-Aviv,Israel

Purpose

To evaluate postoperative photorefractive keratectomy (PRK) visual and refractive outcomes in myopic patients with a thin cornea

Setting

This retrospective study was conducted at Care-Vision Laser Centers in Tel Aviv, Israel, involving consecutive patients who underwent their first PRK surgery between January 2012 and June 2022. The study adhered to the tenets of the Declaration of Helsinki and received institutional review board (IRB) approval for a retrospective chart review. Multiple surgeons performed the procedures using a standardized protocol at a single center equipped with a WaveLight Allegretto EX500 Hz excimer laser.

Methods

A retrospective cohort study of patients with myopia up to -6 diopters who underwent PRK surgery at Care-Vision laser centers, Tel Aviv, between January 2012 and June 2022. Eyes were divided into two groups based on central corneal thickness (CCT); Normal thickness corneas with CCT higher than 450μm and thin corneas with CCT equal or lower than 450μm. Preoperative and intraoperative parameters, percentage of tissue altered (PTA), residual stromal bed (RSB), and postoperative outcomes including uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), Efficacy index, safety index, spherical equivalent (SEQ), and astigmatism accuracy were compared between the two groups. Data was analyzed using the R program. 

Results

A total of 31,670 eyes were studied, including 111 with thin corneas (≤450 μm) and 31,559 with normal thickness. Preoperative BCVA was similar between groups. The normal cornea group had higher myopic treatment larger optical zones and deeper ablation (P<0.0001). Postoperative follow-up duration was comparable (95.71 ± 58.57 days for thin corneas vs. 101.15 ± 64.84 days for normal corneas, P=0.3141). The safety index (1.00 ± 0.14 vs. 1.00 ± 0.14, P=0.9033) and efficacy index (0.98 ± 0.17 vs. 0.98 ± 0.17, P=0.8909) were comparable between both groups. No retreatments or cases of corneal ectasia occurred in the thin cornea group, while the normal cornea group experienced 71 retreatments and 26 cases of corneal ectasia.
 

Conclusions

In this study, we present the largest cohort to date evaluating PRK outcomes in 111 eyes with thin corneas. Our findings demonstrate that PRK for myopic patients with corneas thinner than 450 μm is a safe and effective procedure that has similar efficacy in terms of improving uncorrected visual acuity and similar safety in terms of minimal loss of visual acuity when compared to normal-thickness corneas with no additional risk of corneal ectasia. Our findings highlight the critical importance of careful patient selection and precise planning of intraoperative parameters; such as PTA and RSB.