Efficacy of Combined Phototherapeutic Keratectomy, Wavefront-optimized Photorefractive Keratectomy and Corneal Collagen Crosslinking in the Management of Progressive Keratoconus over One-year Follow-up: Modified Athens Protocol

Abstract

Purpose: Keratoconus is a degenerative, ectatic corneal disorder. Recently, corneal crosslinking (CXL) as a stabilizing procedure has been combined with other procedures to improve visual and refractive outcomes as in Athens and Cretan protocols. The aim of the study is to present the efficacy and safety of a modified Athens protocol over 1-year follow-up. Materials and methods: The study is a retrospective descriptive one with a total of 43 eyes (36 patients) with progressive keratoconus who underwent combined transepithelial phototherapeutic keratectomy (PTK), partial wavefront-optimized photorefractive keratectomy, and corneal collagen CXL. Visual, refractive, pachymetric and keratometric preoperative and postoperative follow-up data at 1 month, 3 months, 6 months, and 1 year were taken from patients’ medical records. Results: The mean uncorrected distance visual acuity (UDVA ) improved from (0.33 ± 0.19) preoperatively to (0.64 ± 0.27) at 1 year postoperatively and the mean corrected distance visual acuity (CDVA) from (0.62 ± 0.21) to (0.80 ± 0.20). At 1-year postoperative visit, the mean spherical and cylindrical values changed significantly from (−2.10 ± 2.45) to (−0.34 ± 2.26) and from (−3.50 ± 1.85) to (−1.23 ± 1.02), respectively. The mean steep and flat K readings significantly decreased from (50.97 ± 4.46) to (47.58 ± 5.61) and from (47.08 ± 4.02) to (44.84 ± 4.47), respectively. The mean Kmax also decreased from (56.27 ± 6.40) preoperatively to (51.22 ± 7.94) postoperatively. The thinnest corneal thickness mean was (462.49 ± 36.17 μm) preoperatively and (388.21 ± 56.64 μm) postoperatively. Conclusion: Our modified Athens protocol has shown to be safe and efficacious in the management of progressive keratoconus. Impressive improvements in visual, refractive, and keratometric values were noted. This approach offers a more tissue saving protocol than the original Athens protocol with less alteration to the surface of the cornea, which may offer more predictability and less refractive surprises.