A Comparative Study Between Diode Laser Cyclophotocoagulation and the Ahmed Glaucoma Valve Implant in Neovascular Glaucoma

Abstract

To compare the efficacy, safety, and long-term results of intraocular pressure (IOP) reduction by diode laser contact cyclophotocoagulation (DCPC) and Ahmed glaucoma valve (AGV) implant in cases of neovascular glaucoma. A total of 66 eyes of 66 patients with neovascular glaucoma were prospectively assigned to either DCPC or AGV implantation. All patients underwent a baseline complete ophthalmologic examination and IOP measurement by Goldmann applanation tonometry before and after 1,3, 6, 12, and 24 months follow-up. Complications and the number of medications were recorded. Mean age of the patients was 60.0+/-11.7 years (range: 20 to 85) in the DCPC group and 57.2+/-10.3 years (range: 20 to 85) in the AGV group. The preoperative IOP was 43.4+/-11.9 mm Hg and 43.3+/-7.4 mm Hg for the DCPC and AGV group, respectively (P>0.05). The postoperative IOP was 16.5+/-11.3 mm Hg and 22.09+/-7.6 mm Hg for the DCPC and AGV groups, respectively (P>0.05) at the last visit. Kaplan-Meier survival analysis showed a probability of success at 24 months of 61.18% and 59.26% for the DCPC and AGV groups (P>0.05). All the patients had a visual acuity of hand movement or worse preoperatively. Visual acuity decreased in 6 eyes (24%) in the DCPC group and 9 eyes (27%) in AGV group. Complications included anterior segment inflammation in 5 eyes (20%), neurotrophic keratitis in 2 eyes (8%), and hypotony in 3 eyes (15%) in the DCPC group and hyphema in 5 eyes (15%) and tube occlusion in 3 eyes (9%) in AGV group. There was no significant difference in the success rate between the DCPC and AGV implantation in neovascular glaucoma treatment. However, DCPC is less time consuming and easier method for lowering IOP in patients with neovascular glaucoma.