Accelerated Epithelium-off Corneal Cross-linking With Preservation of a Central Epithelial Island in the Management of Paracentral Progressive Keratoconus: A Comparative Clinical Trial.

PURPOSE

To evaluate the efficacy and safety of accelerated corneal cross-linking (A-CXL) while preserving the epithelium over the central 3 mm of the cornea compared to epithelium removal CXL in cases of paracentral keratoconus.

METHODS

In this prospective comparative study, 140 eyes of 77 patients were randomized to receive either A-CXL with preservation of the central 3 mm of corneal epithelium or A-CXL with removal of whole corneal epithelium over a central disk area with a diameter of 9 mm. Patients were observed regularly for 1 year after the procedure. The primary outcome measures were to compare early uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA), corneal haze, pain, and discomfort in the first week between the two groups. The secondary outcome measure was keratoconus progression after 12 months of follow-up, measured by the maximum keratometry (Kmax) value.

RESULTS

A significant difference was found between the two groups regarding early postoperative CDVA, corneal haze, pain, and discomfort, with more favorable results in the ACXL with preservation of the central 3 mm of corneal epithelium group. At 12 months of follow-up, a significant improvement in UDVA, CDVA, and Kmax was noticed among patients of the same group, with better final vision and a reduction in Kmax as compared to the preoperative values.

CONCLUSIONS

Preserving the epithelium over the central 3 mm of the cornea during A-CXL in cases with paracentral keratoconus can provide the benefits of immediate early postoperative visual rehabilitation, less corneal haze, less pain, good efficacy, and prevention of keratoconus progression. .