Retrospective Analysis Of Lasik Vs. Prk Outcomes In Myopic Patients With Very Thick Corneas (>600 µm): A Study Of 2095 Eyes

To compare clinical outcomes of LASIK and PRK in myopic patients with very thick corneas (>600 µm). The optimal refractive procedure in such cases remains debated. While LASIK offers faster recovery, concerns about a thinner residual stromal bed may make PRK a preferred option in some cases. This study compares the visual and safety outcomes of LASIK and PRK in this population using a retrospective analysis of 2,095 eyes. Key outcomes include postoperative visual acuity, efficacy and safety indices, retreatment rates, and development of postoperative ectasia.

A retrospective cohort study conducted at Care-Vision Laser Centers, Tel Aviv, Israel. The study included patients aged 20–40 years with myopia up to -12.0D, who underwent PRK or LASIK between January 2010 and June 2024. Data were collected from electronic medical records, ensuring a comprehensive analysis of preoperative, intraoperative, and postoperative parameters.

Patients were divided into PRK and LASIK groups based on surgical technique. Preoperative parameters such as corneal thickness, keratometry, and refractive error were recorded. Intraoperative metrics included optical zone, maximum ablation depth, and residual stromal bed. Postoperative outcomes, including uncorrected and best-corrected distance visual acuity, spherical equivalent, and astigmatism, were assessed at a standardized follow-up visit. Retreatment and ectasia rates were documented. Statistical analysis adjusted for confounders to ensure robust comparisons between groups.

A total of 2,095 eyes were analyzed, including 1,066 PRK and 1,209 LASIK cases. The PRK group was younger (24.92 ± 5.14 vs. 27.46 ± 5.43 years, p <0.0001) and had higher preoperative myopia (-4.56 ± 2.54 vs. -3.36 ± 1.53 D, p <0.0001). Mean preoperative corneal thickness was similar (614.2 ± 13.8 vs. 614.1 ± 14.0 microns, p = 0.96). Postoperatively, LASIK achieved better uncorrected distance visual acuity (UDVA) (0.9855 ± 0.1006 vs. 0.9480 ± 0.1436, p = 0.0001) and efficacy index (1.021 ± 0.107 vs. 1.007 ± 0.147, p = 0.0002). The retreatment rate was higher in PRK (0.84% vs. 0.29%, p = 0.37), though not statistically significant. No cases of ectasia were recorded in either group during the study follow-up period.

In myopic patients with very thick corneas, Both PRK and LASIK are safe and effective. LASIK demonstrated superior efficacy, achieving significantly better uncorrected visual acuity and a higher efficacy index compared to PRK. Safety outcomes slightly favored LASIK, with a lower rate of vision loss and no significant difference in retreatment rates. Despite a thinner residual stromal bed, no cases of ectasia were observed in either group. While both procedures proved effective, these findings suggest that LASIK may offer better refractive outcomes without compromising safety in this population.