Objective: To compare the efficacy of epi-off and epi-on collagen cross-linkage procedure in terms of visual
outcomes and astigmatism during one-year period.
Study Design: Prospective study.
Place and Duration of Study: Amanat Eye Hospital from May 2014 to April 2015.
Materials and Methods: Eighty patients (102 eyes) with keratoconus were included in this study. There were
forty patients (51 eyes) presented with epi-on collagen cross-linkage procedure (Group I) and forty patients (51
eyes) with epi-off collagen cross-linkage procedure (Group II). Epi-off procedure involved epithelial removal
comprised of isotonic riboflavin solution 0.1% with 20% dextran, whereas epi-on procedure involved intact
epithelium utilized hypotonic 0.25% riboflavin solution.
Results: In Group I, the mean age of patients was 21.83 years± 3.83 SD. There were 27 (67.5%) male and 13
(32.5%) female patients. In Group II, the mean age of patients was 20.75years ± 4SD. There were 22 (55%) male
and 18 (45%) female patients. Uncorrected visual acuity improved to 0.04 Log MAR in epi-on and 0.03 Log MAR
in epi-off procedure with p-value=0.7(statistically insignificant), whereas best corrected visual acuity improved
to 0.06 Log MAR in epi-on and 0.02LogMAR in epi-off technique with p-value=0.28 (statistically insignificant)
respectively. However, mean pre-operative topographic astigmatism were (5.51± 2.58) with epi-on procedure
and (3.98 ±2.30) with epi-off procedure, improvement of mean post-topographic astigmatism were improved
in epi-on procedure (5.10 ±2.42) than epi-off procedure (3.96± 2.20).
Conclusion: There was insignificant difference between both cxl procedures. However, improvement of mean
topographic astigmatism were observed in epi-on as compared to epi-off collagen cross linkage procedure.
Epi-On CXL, Epi-Off CXL, Keratoconus, Riboflavin