Purpose
To analyze the influence of corneal cross-linking (CXL) with ultraviolet-A and riboflavin on drug permeability using topically applied pilocarpine.
Methods
Keratoconus patients (n=10) undergoing standard CXL procedure with ultraviolet-A (5.4 J/cm2, 30 minutes) and riboflavin on one eye were included in the study. Pupillary diameter measured before and every 3 minutes for 30 minutes after the topical application of one drop of pilocarpine was used as an indirect measure for corneal permeability. Pupillary diameter was measured with an infrared pupillometer device (Colvard, Oasis Glendora, CA) before (baseline) and 4 months after CXL.
Results
Prior to pilocarpine application no significant difference in pupillary diameter was found before CXL and 4 months later (p>0.05). Mean decrease of pupillary diameter 30 minutes after the application of pilocarpine was significantly higher at baseline compared to 4 months follow-up examination (mean decrease of 4.3 vs. 3.5 mm; p=0.03).
Conclusions
CXL reduces corneal permeability for pilocarpine in humans.
Keywords: 479 cornea: clinical science