Collagen shield delivery of trifluorothymidine

Corneal and aqueous levels of topically applied trifluorothymidine (F3T) were compared with and without the collagen shield in normal and damaged rabbit eyes. Shields were presoaked in 1% F3T for 15 minutes prior to application. Rabbits received either a presoaked shield, 1% F3T drops every two hours, or both. Corneal and aqueous levels of F3T were measured at 30 minutes, two, four, and eight hours. If 5 mm epithelial defects were created, the collagen shield and topical F3T drops produced significantly higher levels of F3T than drops alone at all periods tested (P less than .05). A presoaked shield alone produced greater levels of F3T than drops alone at 30 minutes and two hours (P less than .05). Collagen shields did not enhance F3T levels in eyes with intact epithelium. Implications for treatment of herpetic keratouveitis are discussed.