Abstract:
Purpose: The purpose of the present study was to assess the long-term efficiency and safety of
the “epi-off” accelerated CXL (9 mW/cm2 for 10 minutes) in comparison to the standard “epi-off”
CXL (3 mW/cm2 for 30 minutes) in terms of topographical and keratometric parameters, refractive
data and visual outcomes at 7 years of follow-up, in progressive keratoconus.
Material and method. A retrospective and comparative study was performed. A total of 183 eyes
from 183 patients with documented progressive KCN were included in the study. The patients
were divided in two groups: 93 eyes from 93 patients underwent “epi-off” standard cross-linking
technique (3 mW/cm2 for 30 minutes) (S-CXL group) and 90 eyes from 90 patients underwent
accelerated “epi-off” corneal CXL technique (9 mW/cm2 for 10 minutes) (A-CXL group).
Results: Improvements in uncorrected distance visual acuity (UDVA) were statistically significant
compared to baseline values in both groups at each time-point visit. (p=0.0421 at 1 year, p=0.0411
at 7 years for A-CXL and p=0.0375 at 1 year, p=0.0389 at 7 years for S-CXL). At 7 years there
was a statistically significant increase in CDVA (p=0.039 in the A-CXL group and p=0.0343 in
the S-CXL group at 7 years). Statistically significant reduction was noticed in Ksteep (p=0.0411
in A-CXL group and p=0.0224 in S-CXL group), Kflat (p=0.0198 in A-CXL group and p=0.008
in S-CXL group), K mean (p=0.0106 in A-CXL group and p=0.0193 in S-CXL group) and Kmax
(p=0.0413 in A-CXL group and p=0.054 in S-CXL group) at 7 years, compared to baseline values,
in both groups, but without any statistically difference between the two procedures, at all timepoint visits (p>0.05).
Conclusions: The long-term outcomes of “epi-off” accelerated corneal collagen crosslinkingUVA (9 mW/cm2 for 10 minutes) are similar to standard “epi-off” corneal collagen crosslinking
procedure in the treatment of progressive keratoconus.
