Medical neuroprotection—a holy grail of glaucoma research—continues to elude us. A team of US and Australian researchers discovered that daily treatment with oral memantine over a period of 48 months did not prevent open-angle glaucoma (OAG) progression.

The study evaluated 2,298 patients at risk of glaucomatous progression who had bilateral OAG, glaucomatous optic disc damage and visual field loss in one eye, glaucomatous optic disc damage and/or visual field loss in the other eye and a topically treated or untreated intraocular pressure (IOP) of 21mm Hg or less at baseline. Participants received the drug at 20mg,10mg or placebo tablets daily. The team then assessed glaucomatous progression by full-threshold standard automated perimetry (SAP), frequency doubling technology (FDT) and optic disc photographs. They also performed biomicroscopy and ophthalmoscopy evaluations to measure the safety of memantine by looking for adverse events (AEs), best-corrected visual acuity and IOP.

The researchers found that, compared with the placebo group, the groups that were treated with memantine did not experience significant delayed glaucomatous progression. They note that the risk reduction ratios assessed by SAP were -0.17 for the 20mg dose and -0.13 at 10mg. They add that FDT and optic disc photographs arrived at similar results. The proportion of patients who completed the studies was similar among all three groups (80% to 83%); the most common AEs leading to treatment discontinuation were dizziness, headaches, fatigue and nausea, according to the researchers.