Abstract
Purpose :
To assess the impact of riboflavin replenishment during corneal cross-linking (CXL).
Methods :
51 porcine eyes were assigned to 6 groups. Group 1 remained untreated. Groups 2-6 received a 16-minute application of 0.1% riboflavin/HPMC. Group 3 was then exposed to 9 mW/cm2 UVA for 10 minutes. Groups 4-6 were also exposed to 9 mW/cm2 UVA for 10 minutes but received a midway replenishment of riboflavin during continuous irradiation (Group 4) or in association with a 1-minute (Group 5) or 2-minute (Group 6) break in UVA exposure. Central corneal thickness (CCT) was recorded before and after treatment. Trephined 8.0 mm central corneal buttons were subjected to 0.3% collagenase digestion at 37°C and monitored at 1-hour intervals to determine the time required for complete digestion.
Results :
A midway replenishment of riboflavin during continuous UVA exposure maintained CCT during treatment, whereas no riboflavin replenishment or riboflavin replenishment accompanied by a 1–2-minute break in UVA exposure resulted in a small but significant reduction in CCT (P<0.01). All CXL-treated corneas displayed a 2-5-fold increase in resistance to collagenase digestion compared to non-irradiated corneas. However, no significant differences in enzymatic resistance were detected between any of the CXL groups.
Conclusions :
All CXL protocols were effective at enhancing the resistance of the cornea to collagenase digestion. The inclusion of a midway replenishment of riboflavin did not significantly increase CXL effectiveness but, with continuous UVA exposure, did help to maintain tissue thickness during treatment.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.