Biomechanical, Visual, and Refractive Outcomes of Total Corneal Wavefront-Guided Transepithelial PRK With Accelerated CXL in Keratoconus Using Objective Stability Markers.

PURPOSE: To evaluate the long-term safety and efficacy of simultaneous total corneal wavefront-guided transepithelial photorefractive keratectomy (TCWG-TransPRK) with accelerated corneal cross-linking (CXL) in mild to moderate keratoconus, incorporating corneal biomechanics as objective markers of structural stability.

METHODS

This prospective, interventional, single-center study included patients with mild to moderate keratoconus. All underwent TCWG-TransPRK (maximum planned stromal ablation: 55 µm) followed by accelerated CXL (30 mW/cm2 for 3 minutes; total fluence: 5.4 J/cm2). Follow-up was conducted at 24 hours, 1 week, and 1, 3, 6, and 12 months. Primary outcomes were safety and efficacy, with stress-strain index version 2 (SSI v2) proposed as a key objective marker of biomechanical stability. Additionally, refractive accuracy, tomography, and epithelial remodeling were evaluated.

RESULTS

Thirty-eight eyes from 19 patients were analyzed. At 12 months, uncorrected distance visual acuity improved from 0.80 ± 0.36 to -0.03 ± 0.10 logarithm of the minimum angle of resolution (P < .0001), with 87% achieving 20/20 and all 20/40 or better. Corrected distance visual acuity improved (P < .0001), with no Snellen line loss. Refractive accuracy was high (89% within ±1.00 diopter). SSI v2 increased significantly (P < .0001), indicating enhanced intrinsic stiffness. No keratoconus progression was observed. Epithelial thickness increased nasally and temporally, correlating with changes in spherical aberration and vertical trefoil.

CONCLUSIONS

Despite the use of accelerated CXL parameters, TCWG-TransPRK with CXL improved vision and enhanced biomechanical stability, as evidenced by a significant increase in SSI v2. This provides an objective structural marker for monitoring and customizing keratoconus care. These findings support the procedure as a safe and effective option for non-progressive mild to moderate keratoconus.