Document Type : Original Article
University of Basrah
Aim of the Study:
Using anterior segment optical coherence tomography (AS-OCT) to compare the depth of corneal demarcation line (DL) after corneal collagen cross-linking (CXL) with subtotal versus customized corneal epithelium debridement.
Prospective multi centric 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 scratch ). One month postoperatively, patients had AS-OCT imaging to detect and measure the depth of DL.
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 micro m while in customized epi-off treatment 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 micro m 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 treatment.
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.