EVALUATING THE LONG-TERM EFFECTS OF GAS PERMEABLE LENSES ON CORNEAL ENDOTHELIAL: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract Introduction: Rigid Gas permeable (GP) lenses are widely used for vision correction, but their long-term effects on the corneal endothelium remain uncertain. This systematic review and meta-analysis aimed to evaluate the impact of GP lens wear on corneal endothelial cell density, morphology, and function. Methods: A systematic search of PubMed, Scopus, Web of Science, and Cochrane Library identified cohort and case-control studies reporting endothelial cell density, morphology, and pleomorphism in individuals wearing GP lenses for over six months. Two reviewers independently extracted data, and the Newcastle-Ottawa Scale was used to assess bias risk. A random-effects model meta-analysis calculated pooled estimates of GP lenses' effects on endothelial parameters. Results: Meta-analysis comparing GP lenses to controls revealed no significant differences in endothelial parameters. For endothelial cell density, the mean difference was 4.40 (p = 0.207, Confidence Interval (CI): -2.43 to 11.24, I² = 99.62%). Endothelial coefficient of variation (ECV%) showed a mean difference of -5.60 (p = 0.245, CI: -15.03 to 3.84, I² = 99.77%), while endothelial hexagonality (HXG%) had a mean difference of -3.15 (p = 0.190, CI: -11.26 to 4.96, I² = 97.45%). Substantial heterogeneity across studies limits definitive conclusions. Conclusion: GP lenses do not significantly impact corneal endothelial parameters, including ECD, ECV%, and HXG%, compared to controls. Further research is required to validate these findings and assess long-term effects on endothelial integrity.