Clinical Observation of Wavefront-Guided Transepithelial Photorefractive Keratectomy with Simultaneous Accelerated Corneal Collagen Cross-Linking in Early Keratoconic Patients

Objective: To observe the efficacy and safety of wavefront-guided transepithelial photorefractive keratectomy (WG-TransPRK) with simultaneous accelerated corneal collagen cross-linking (A-CXL) in early-stage keratoconus. Methods: In this retrospective study, twelve eyes of 7 patients with early keratoconus underwent simultaneous WG-TransPRK with A-CXL. Visual acuity, refractive status, topography, confocal microscopy and aberrations were examined before treatment and 1 week, 1 month, 3 months, 6 months, and 12 months after surgery. Data were analyzed by paired t test. Results: Twelve months after the surgery, the average UCVA improved from 0.77±0.25 LogMAR to 0.34±0.26 LogMAR (P=0.001), the average BCVA improved from 0.18±0.21 LogMAR to 0.05±0.09 LogMAR (P=0.034). The K1, K2 spherical equivalent of the cornea were reduced from 43.85±1.72 D and 46.64±2.36 D to 40.63±2.13 D (t=9.48, P=0.001) and 42.27±1.89 D (t=8.29, P=0.001), respectively. And Kmax decreasing from 48.88±3.62 D to 45.43±1.54 D (t=3.02, P=0.014). Sub-basal nerve density decreased (P=0.001). The anterior and mid-stromal keratocyte density was reduced also (P<0.05). No significant change was detected in the deep stromal and endothelial cell density. The aberration parameters decreased in the 4 mm diameter analysis area (P<0.05). Conclusion: WG-TransPRK combined with simultaneous A-CXL is safe and effective for the treatment of early-stage keratoconus, with an improvement in visual acuity. Key words: photorefractive keratectomy; corneal collagen cross-linking; keratoconus; aberration