Purpose: To compare standard epithelium-off corneal cross-linking (standard Epi-Off CXL) to corneal cross-linking with an epithelial flap (Epi-Flap CXL).
Methods: Patients who had undergone sequential bilateral CXL for progressive keratoconus were included in this comparative interventional case series. One eye was treated with the Epi-Off CXL technique and the fellow eye with the Epi-Flap CXL technique. Postoperative pain was measured using the Verbal Rating Scale and corneal densitometry using a Scheimpflug camera. Sex, age, corrected distance visual acuity, keratometry, and corneal thickness were also recorded.
Results: Twenty-four eyes of 12 patients with keratoconus with a mean age of 27.15 ± 5.15 years were included. The Verbal Rating Scale scores were significantly lower in patients who had Epi-Flap CXL on the first (1.00 [interquartile range (IQR): 0.00 to 1.00] vs 3.00 [IQR: 3.00 to 3.75], P = .01) and third (0.00 [IQR: 0.00 to 1.00] vs 1.00 [IQR: 0.00 to 1.00], P = .01) postoperative day compared to the Epi-Off CXL group. No pain was observed in both groups after the third day. After 12 months, the Epi-Flap CXL group showed significantly less anterior corneal haze (measured as corneal densitometry) compared to the patients treated with Epi-Off CXL (P = .01). Both groups demonstrated stability of keratometry and corneal thickness at 12 months after CXL (P < .01).
Conclusions: Epi-Flap CXL is associated with less postoperative pain and anterior stromal haze in patients undergoing CXL for progressive keratoconus with no loss of efficacy. [J Refract Surg. 2021;37(11):741-745.].