Topography-guided photorefractive keratectomy combined with accelerated corneal collagen cross-linking (The Athens Protocol) for keratoconus

Abstract

Objective The aim was to evaluate corneal changes after topography-guided partial photorefractive keratectomy (PRK) combined with accelerated corneal collagen cross-linking (CXL) (the Athens protocol) in progressive keratoconus with Pentacam Scheimpflug imaging. Background Keratoconus is a bilateral noninflammatory progressive corneal thinning that results in irregular astigmatism and progressive myopia. Topography-guided partial PRK combined with CXL (The Athens Protocol) has been developed not only to arrest progression of keratoconus but also to offer the patients functional vision. Patients and methods This prospective study included 20 eyes that underwent topography-guided partial PRK combined with accelerated CXL (The Athens Protocol). Preoperative and postoperative assessments included visual acuity, slit lamp evaluation, and Pentacam. All investigation and examination were done during the period from June 2017 to June 2018. Results All study parameters demonstrated a statistically significant improvement with uncorrected distance visual acuity of 0.55 ± 0.29 Snellen line postoperatively vs. 0.33 ± 0.24 Snellen line preoperatively and best-corrected visual acuity of 0.73 ± 0.25 Snellen line postoperatively vs. 0.61 ± 0.27 Snellen line preoperatively, with a P value of 0.005; flat keratometry of 44.76 ± 1.64 D postoperatively vs. 45.29 ± 2.01 D preoperatively and steep keratometry of 46.55 ± 2.09 D vs. 47.68 ± 2.42 D, preoperatively, with a P value of less than 0.001; mean postoperative index of surface variance of 50.70 ± 18.34 postoperatively vs. 65.25 ± 29.29 preoperatively, with P value less than 0.001; and mean postoperative index of height decentration of 0.053 ± 0.033 postoperatively vs. 0.091 ± 0.052 preoperatively, with P value less than 0.001. Conclusion Topography-guided partial PRK combined with accelerated CXL (The Athens Protocol) is a relatively new and revolutionary procedure aimed at stabilization of corneal ectatic disorders and achieving a good visual quality. Longer duration of follow-up and a larger sample may further provide more reliable results.