Comparison of pain after subepithelial versus conventional accelerated corneal collagen cross-linking for keratoconus.

Purpose: To compare the postoperative pain and epithelial healing time in conventional and subepithelial accelerated corneal collagen cross-linking (CXL) for progressive keratoconus.
Methods: The medical records of 27 consecutive patients who underwent accelerated CXL for progressive keratoconus were retrospectively reviewed. Patients were divided into two groups: the conventional (n = 16) and the subepithelial accelerated CXL group (n = 11). Corneal epithelial layers with a diameter of 8.5 mm in central corneas were removed in the conventional group, while epithelial flaps with the same diameter were prepared in the subepithelial group before accelerated CXL procedures. Postoperative pain and epithelial healing time were evaluated within 1 week.
Results: No complications developed in the subepithelial group, whereas peripheral corneal sterile infiltrate was observed in three eyes in the conventional group, which disappeared after treated with steroids for a week. The pain of patients in subepithelial group was significantly slighter than those in conventional group, with a significant difference in pain scoring 0, 1, 2 and 3 days postoperatively (P = 0.002, P = 0.001, P = 0.001, P = 0.001, respectively). Different from the fact that patients in subepithelial group had epithelium after operation, the healing time for epithelium in conventional group was 3-6 days, with an average of 4.64 ± 0.59 days.
Conclusions: Subepithelial accelerated CXL significantly improved postoperative pain as well as reduced the epithelial healing time for the treatment of keratoconus.