A prospective, comparative study between endoscopic cyclophotocoagulation and the Ahmed drainage implant in refractory glaucoma

PURPOSE: To compare endoscopic cyclophotocoagulation (ECP) and the Ahmed drainage implant in the treatment of refractory glaucoma. METHODS: Sixty-eight eyes of 68 patients with refractory glaucoma were prospectively assigned to either ECP or Ahmed tube shunt implantation. All procedures were performed by a single surgeon. Eyes that were included were pseudophakic with a history of at least one trabeculectomy with antimetabolite, an intraocular pressure (IOP) equal to or above 35 mm Hg on maximum tolerated medical therapy, and a visual acuity better than light perception. Exclusion criteria included eyes that had had previous glaucoma drainage device implantation or a cyclodestructive procedure. Success was defined as an IOP more than 6 mm Hg and less than 21 mm Hg, with or without topical anti-hypertensive therapy. RESULTS: The mean follow-up was 19.82 +/- 8.35 months and 21.29 +/- 6.42 months, for the Ahmed and ECP groups, respectively (P = 0.4). The preoperative IOP, 41.32 +/- 3.03 mm Hg (Ahmed) and 41.61 +/- 3.42 mm Hg (ECP) (P = 0.5), and the mean postoperative IOP, at 24 months follow-up, 14.73 +/- 6.44 mm Hg (Ahmed) and 14.07 +/- 7.21 mm Hg (ECP) (P = 0.7), were significantly different from baseline in both groups (P < 0.001). Kaplan-Meier survival curve analysis showed a probability of success at 24 months of 70.59% and 73.53% for the Ahmed and ECP groups, respectively (P = 0.7). Complications included choroidal detachment (Ahmed 17.64%, ECP 2.94%), shallow anterior chamber (Ahmed 17.64%, ECP 0.0%), and hyphema (Ahmed 14.7%, ECP 17.64%). CONCLUSION: There was no difference in the success rate between the Ahmed Glaucoma Valve and ECP in refractory glaucoma. The eyes that underwent Ahmed tube shunt implantation had more complications than those treated with ECP.