Study Reviews Ahmed Valve Implantation Techniques

An ARVO study reviewed 2 methods of neovascular glaucoma treatments.

This article is part of Ophthalmology Advisor’s conference coverage from the 2021 meeting of The Association for Research in Vision and Ophthalmology (ARVO), held virtually from May 1 to 7, 2021. The team at Ophthalmology Advisor will be reporting on a variety of the research presented by the eye and vision experts at ARVO. Check back for more from the ARVO 2021 Meeting.


Both pars plana and anterior chamber Ahmed glaucoma valve implant placements were effective in lowering intraocular pressure (IOP) and visual acuity, according to research results presented at the Association for Research in Vision and Ophthalmology (ARVO) 2021 Annual Meeting, held virtually from May 1 to 7, 2021. 

In a retrospective study, researchers investigated Ahmed glaucoma valve implants in patients with neovascular glaucoma between 2010 and 2020 to compare patient outcomes. The study reviewed 2 groups of patients. Group 1 underwent pars plana Ahmed glaucoma valve implant plus pars plana vitrectomy with endolaser. Group 2 underwent anterior chamber Ahmed glaucoma valve implant plus panretinal photocoagulation. 

The primary outcome measure — changes in IOP and visual acuity — was measured between groups and compared at 6 months and 1 year. 

Each group included 15 participants; 73% of eyes in group 1 were pseudophakic compared with 20% of eyes in group 2. Mean baseline IOP and visual acuity were similar (38.6±6.6 mm Hg vs 43±8.9 mm Hg and 1.4±0.7 logMAR vs 1.3±0.8 logMAR, respectively). 

At 6 months and 1-year, adjusted change in IOP was not statistically significant between groups. Adjusted visual acuity change was also not statistically significant at these time points. Among group 1 participants, 2 eyes had foveal macular edema, 1 developed retinal detachment, and 1 had rapid cataract progression. Among group 2, 1 eye required a tube revision, 1 required additional transscleral laser therapy, and 2 had cataract surgery

“[The procedures] were both effective in lowering IOP, and there was no significant difference between them,” according to researchers. “There was a trend toward better [visual acuity] at year 1 in group 2, but this was not statistically significant.” 

“A prospective study and larger sample size is needed to address this question and further evaluate the outcomes of both treatment modalities,” they report. 

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Yazdanie MS, Nimmagadda S, Sadhra H, et al. Pars plana Ahmed valve with vitrectomy and endolaser versus anterior chamber Ahmed valve with pan retinal photocoagulation: A comparison of two treatments for neovascular glaucoma. Presented at: Association for Research in Vision and Ophthalmology (ARVO) 2021 Annual Meeting; May 1-7, 2021. Abstract 3503989.