Aim of the Study:

Compare the corneal demarcation line (DL) depth after corneal collagen cross-linking (CXL) with subtotal versus customized corneal epithelium debridement using anterior segment optical coherence tomography (AS-OCT).

Design:

Prospective case-control study.

Materials and Methods:

The study enrolled 18 patients with bilateral progressive keratoconus. Both eyes treated by CXL using 3 mW/cm2 / 30 minutes setting. One eye with subtotal epithelial debridement (about 9 mm diameter) and the contralateral eye with customized debridement (approximately 1 mm single horizontal central scratch). One month postoperatively, patients had AS-OCT imaging to detect and measure the depth ofDL.

Results:

Patients’ age mean was 25.17 years +/- 4.81 SD. Epithelial healing completed with in 3-7 days in conventional treatment group and demarcation line was evident in 16 eyes (89%) with a mean depth of 290.31 µm while in customized debridement group, the epithelial healing lasted less than 24 hours and DL was detectable in 10 patients (55.5 %) with a mean DL depth of 221 µm with a statistically significant difference (p < 0.05). Subjective postoperative pain graded as “moderate to severe” in about 77% of eyes underwent 9 mm epi-off CXL compared with 55% of those with customized debridement group.

Conclusions:

Although the DL if found in majority cases, but the shallow location in customized corneal debridement cases questioned the efficacy of this technique despite the quick re-epithelialization and less postoperative pain that accompanied it