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

To evaluate long-term complications related to glaucoma drainage devices in patients undergoing Boston type 1 keratoprosthesis surgery.

Retrospective case series.

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.

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.

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.