Evaluation of Corneal Structural Changes and Visual Acuity Improvement in Keratoconus Patients Following Corneal Cross-Linking (CXL) and Photorefractive Keratectomy (PRK): Assessment Using Pentacam Imaging System

Purpose: Keratoconus is a progressive, non-inflammatory corneal disease with thinning and protrusion, and vision distortion. The present study addresses the structural change of the cornea and visual acuity improvement in keratoconus patients treated with CXL and PRK with the help of the Pentacam imaging system. Methods: In this retrospective study, 87 stage 1 or 2 keratoconus patients underwent PRK and then CXL. The inclusion criteria were 12-month documented progression and corneal thickness ≥450 μm. Exclusion criteria were age <18, advanced keratoconus, previous refractive surgery, and pregnancy. Pre-and post-operative visual acuity, topography, and tomography were compared. Paired samples t-test and linear regression analysis were conducted. Results: 87 eyes of 45 patients (age: 30.47 pre-op, 34.21 post-op on average). There was significant postoperative improvement in vision with 47.1% reverting to LogMAR 0.0. Significant reductions were seen in Pentacam corneal parameters barring inferior steepening (IS). Linear regression analysis revealed age and preoperative thickness as independent predictors for K1 F and K2 F change. Conclusion: CXL with PRK is promising in the treatment of mild and moderate keratoconus with improvement and stabilization of vision. Further studies are warranted to continue developing treatment protocols as well as address residual irregularities.