Optimal resistance to in vitro keratolysis by collagenase A can be achieved by collagen crosslinking the deepithelialized anterior corneal surface for 30 minutes, according to a recently published study.
Optimal resistance to in vitro keratolysis by collagenase A can be achieved by collagen crosslinking the deepithelialized anterior corneal surface for 30 minutes, according to a study published in Cornea.
In a basic investigation, Barron artificial anterior chambers were used to perform ex vivo crosslinking of human corneas. The deepithelialized corneas were pretreated with riboflavin solution and irradiated with ultraviolet A (UVA) light for various durations. The corneas were then trephined and incubated with 0.3% collagenase A solution at 37 °C.
It was found that deepithelialized corneas that received no UV light and no riboflavin dissolved in 5.8 ± 0.6 hours. Increased resistance to dissolution was found in the crosslinked corneas, which demonstrated a time to dissolution of 17.8 ± 2.6 hours.
Longer UVA exposure increased the corneal tissues' resistance to collagenase, reaching a plateau at 30 minutes. Crosslinking the anterior corneas only provided the same amount of resistance as crosslinking both the anterior and posterior corneas.
Corneas that had been gamma-irradiated did not benefit from further crosslinking. They dissolved in 5.6 ± 1.2 hours when further crosslinked and 6.1 ± 0.6 hours when not.