Long-term complications associated with glaucoma drainage devices and boston keratoprosthesis

Purpose: To evaluate long-term complications related to glaucoma drainage devices in patients undergoing Boston type 1 keratoprosthesis surgery. Design: Retrospective case series. Methods: All patients who underwent Boston type 1 keratoprosthesis surgery at the University of California, Davis, between 2004 and 2010 were included. Preoperative and postoperative data were reviewed. Twenty-five eyes with glaucoma drainage devices were highlighted. Visual acuity and postoperative complications were tracked at postoperative months 1, 3, 6, 9, and 12 and at annual intervals thereafter. Results: Forty eyes of 35 patients were evaluated with an average follow-up of 33.6 months. Conjunctival breakdown occurred in association with 10 glaucoma drainage device implants in 9 eyes. Eleven eyes had glaucoma drainage devices placed before keratoprosthesis surgery, 3 eyes underwent glaucoma drainage device placement at the time of surgery, and 2 eyes had a glaucoma drainage device placed after surgery. All but one of the eroded glaucoma drainage devices were placed before surgery. Associated complications included endophthalmitis, hypotony, and keratoprosthesis extrusion, with 6 glaucoma drainage devices requiring removal. Long-term beset-corrected visual acuity was maintained better in eyes in which glaucoma drainage device erosions did not develop. Conclusions: One of the main challenges with keratoprosthesis surgery is treating concurrent glaucoma. Glaucoma drainage devices have been advocated as a way to address this long-term complication, but this series suggests that glaucoma drainage device-related complications can cause significant vision loss.