Purpose
Our purpose was to compare the efficacy of ‘epithelium-off’ and ‘epithelium-on’
cross-linking (CXL) in treatment of progressive keratoconus.
Patients and methods
This study included 48 eyes of 26 patients who met our inclusion criteria. The Epi-
Off CXL group included 32 eyes of 17 patients, and the Epi-On CXL group included
16 eyes of nine patients. Preoperative assessments of uncorrected and bestcorrected
visual acuities, refractive errors, keratometry, and corneal tomography
including pachymetry, were compared with the postoperative values.
Results
Preoperatively, there was a statistically nonsignificant difference between the two
groups in all studied variables except for the pachymetry at thinnest location. In the
Epi-Off group, there was a significant improvement of uncorrected visual acuity,
best-corrected visual acuity, Kmax, and inferior–superior value at the 12-month visit.
There was late significant worsening of the back elevation and spherical equivalent
at the 12-month visit and also significant thinning of pachymetry at thinnest location
associated with significant worsening of the average thickness increase. All other
variables showed nonsignificant change (stabilization) at both postoperative visits.
In the Epi-On group, there was significant thinning of pachymetry at thinnest
location and stabilization of uncorrected corrected visual acuity, best-corrected
visual acuity, K1, Kmax, (inferior–superior), Y-coordinate, and front elevation at both
postoperative visits, and early stabilization with late worsening of all of other
variables.
Conclusion
The Epi-Off CXL was found to be more superior to Epi-On CXL in terms of
stabilization of progressive keratoconus but was inevitably associated with
complications related to epithelial debridement.