A Comparative Study Between Diode Laser Cyclophotocoagulation and the Ahmed Glaucoma Valve Implant in Neovascular Glaucoma A Long-term Follow-up Nilgun Yildirim, MD,* Ilgaz Sagdic Yalvac, MD,w z Afsun Sahin, MD,* Ahmet Ozer, MD,* and Tarık Bozca, MDy Background: 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. Methods: 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 ophthal- mologic 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. Results: 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%), neuro- trophic 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. Conclusions: 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. Key Words: Ahmed glaucoma valve, diode laser cyclophotocoagu- lation, neovascular glaucoma (J Glaucoma 2009;18:192–196) N eovascular glaucoma is one of the refractory types of glaucoma. It is caused by a number of ocular and systemic conditions, which causes retinal ischemia that initiates the subsequent release of angiogenic factors. The most common causes of neovascular glaucoma are diabetic retinopathy and the occlusion of retinal vein, carotid artery, and central retinal artery. 1–3 The important point in successful treatment of neovascular glau- coma is early detection of the neovascularization process. Panretinal photocoagulation 4 and intravitreal antivascular endothelial growth factor remain to be the most effective management. 5 However, both cyclodestructive procedures and tube-shunt-type glaucoma drainage implants are generally reserved for eyes with refractory more conven- tional treatments. Using a variety of different methods, cyclodestruction has been used in the reduction of aqueous formation and intraocular pressure (IOP) for many years. The 2 of the most common methods of cyclodestruction currently in use are cryotherapy and laser photocoagulation. Cyclodestruc- tion using cryotherapy is associated with high-risk vision threatening complications. 6,7 Recently, diode laser has been employed for cycloablation in the management of glauco- mas. 8–14 Cyclodestruction by diode laser cyclophotoco- agulation (DCPC) is achieved by transcleral application of infrared light, which is mainly absorbed by the pigmented epithelial cells of the ciliary body resulting in the destruction of ciliary body epithelium and coagulation necrosis of ciliary body stroma. 8,13,15 Immediate and late complications including corneal edema, hypotony, and phthisis bulbi are rare, and it seemed safer than cyclo- cryotherapy. 8,13,16 Glaucoma drainage implants are another treatment choice in the treatment of neovascular glaucoma. 17,18 The Ahmed glaucoma valve (AGV) (New World Medical, Cucamonga, CA) has a valve mechanism, which theoreti- cally restricts flow until a pressure of greater than 8 to 12 mm Hg is exerted upon it. It has comparable success rates to other glaucoma drainage devices for refractory glaucoma, 19–21 and less hypotony was observed in the early postoperative period. 22 To date, there is limited data about the long-term results of DCPC and AGV implantation in neovascular glaucoma. 23 The purpose of this study is to compare the efficacy, safety, and long-term results of DCPC and AGV implantation in neovascular glaucoma cases secondary to diabetic retinopathy and retinal vein occlusion. Copyright r 2009 by Lippincott Williams & Wilkins Received for publication January 7, 2007; accepted April 20, 2008. From the *Department of Ophthalmology, Eskisehir Osmangazi University Hospitals, Meselik, Eskisehir; wDepartment of Opthal- mology, Ankara Training and Research Hospital, Ankara; zYeditepe University Eye Hospital, Istanbul; and yPrivate Practice, Artvin, Turkey. Reprints: Nilgun Yildirim, MD, Department of Ophthalmology, Eskisehir Osmangazi University Hospital, Eskisehir, Turkey (e-mail: nyyildirim@yahoo.com). ORIGINAL STUDY 192 J Glaucoma  Volume 18, Number 3, March 2009