Glaucoma Patch Graft Surgery Utilizing Corneas Augmented with Collagen Cross-linking

PURPOSE: Glaucoma drainage device surgery (GDDS) has gained popularity, with outcomes equivalent to trabeculectomy. Erosion of the tube through the overlying conjunctiva may occur in 5%–10% of eyes. Donor corneal tissue has been used as a patch graft for GDDS. MATERIALS AND METHODS: This was a prospective proof of concept study in 10 patients undergoing GDDS. From patients undergoing endothelial keratoplasty, the donor tissue (approximately 300 μ in thickness) was placed epithelial side down in a well and was allowed to soak in riboflavin solution (VibeX, Avedro, Waltham, MA, USA) for 15 min. This anterior corneal lenticule received 8 mW/cm(2) ultraviolet (UV) irradiation applied for 15 min (total energy of 7.2 J/cm(2)). Each lenticule was then bisected and utilized for the two study participants. The tissue was sutured over the tube during the GDDS and then was covered with recipient conjunctiva as per the usual technique. Representative graft tissues were fixed and examined to determine the depth of cross-linking effect. The patients were followed for 1 year. RESULTS: Histology revealed no apparent demarcation line in the cross-linked grafts; this supported a full-thickness cross-linking treatment effect. There were no intra- or postoperative complications attributed to the graft tissue. No patient developed erosion or exposure of the tube during the 1-year follow-up. CONCLUSIONS: UV-riboflavin cross-linking of the corneal tissue patch graft material appears to be a safe modification when used in GDDS and warrants ongoing study. This method of patch graft can replace other costy methods used with GDD.