Trabeculectomy versus Ahmed Glaucoma Valve implantation in neovascular glaucoma

Christopher C Shen¹, Sarwat Salim², Haiming Du², Peter A Netland^3
1Glaucoma Consultants Northwest, Seattle, WA, USA; ²University of Tennessee Health Science Center, Memphis, TN, USA; ³University of Virginia School of Medicine, Charlottesville, VA, USA

Purpose: To compare surgical outcomes in neovascular glaucoma patients who underwent trabeculectomy with mitomycin C versus Ahmed Glaucoma Valve implantation.
Patients and methods: This was a retrospective comparative case series. We reviewed 40 eyes of 39 patients with underlying diagnosis of neovascular glaucoma, divided into two groups: Ahmed Glaucoma Valve (N = 20) and trabeculectomy with mitomycin C (N = 20). Surgical success was defined as 6 mm Hg ≤ intraocular pressure ≤ 21 mm Hg, with or without the use of glaucoma medications, with no further glaucoma surgery, and light perception or better vision. Early postoperative hypotony was defined as intraocular pressure < 5 mm Hg during the first postoperative week.
Results: The average follow-up was 31 months (range 6–87 months) for the Ahmed Glaucoma Valve group and 25 months (6–77 months) for the trabeculectomy group. Although the mean number of postoperative intraocular pressure-lowering medications was significantly higher in the trabeculectomy group compared with the Ahmed Glaucoma Valve group at 3 and 6 month time points, there was no statistically significant difference at any other time point. There was no statistically significant difference between both groups in postoperative visual acuity and intraocular pressure. Success was 70% and 65% at 1 year and 60% and 55% at 2 years after Ahmed Glaucoma Valve and trabeculectomy, respectively. Kaplan–Meier survival curve analysis showed no significant difference in success between the two groups (P = 0.815). Hyphema was the most common complication in both groups.
Conclusion: We found similar results after trabeculectomy with mitomycin C and Ahmed Glaucoma Valve implantation in eyes with neovascular glaucoma.

Keywords: glaucoma drainage implant, glaucoma filtering surgery, mitomycin C, neovascular glaucoma, intraocular pressure