Delivery of trifluridine to human cornea and aqueous using collagen shields.

PURPOSE: We investigated the ability of collagen shields to deliver trifluridine (trifluorothymidine [TFT]) to human cornea and aqueous humor.

METHODS

24-hour porcine collagen shields were soaked in commercially prepared TFT (Viroptic). Patients undergoing penetrating keratoplasty wore a pre-soaked collagen shield for at least 30 minutes preoperatively. Control patients received drops of TFT only. Cornea and aqueous samples were obtained. TFT levels were measured using high performance liquid chromatography.

RESULTS

Among the four patients with intact corneal epithelium, TFT was detected in only one patient (0.13 microgram/g in the aqueous). In seven patients with poor epithelium, corneal levels ranged from 0 to 635.34 micrograms/g, and aqueous levels ranged from 0.06 to 11.17 micrograms/g.

CONCLUSIONS

Collagen shields do not enhance delivery of TFT to corneas with intact epithelium. In corneas with poor epithelium, drug penetration was higher but variable. The role of collagen shields as a drug delivery system for the treatment of herpes simplex keratitis remains to be determined.