Efficacy of Memantine in Acute Non-Arteritic Ischemic Optic Neuropathy

Purpose: evaluation of efficacy of memantine (n-methyl-d-aspartate receptor antagonist) on visual function of patients with acute non-arteritic ischemic optic neuropathy (naion).methods: the study was conducted as interventional case series from november 2005 through november 2006 in farabi eye hospital. twenty-two patients with acute naion of less than 8 weeks duration entered the study. memantine was prescribed with a dose of 5 mg per day for the first week and 10 mg per day for the following two weeks. baseline best corrected visual acuity (bcva); visual evoked potential (vep) and visual field was done for all patients. bcva recording repeated 3 weeks, 3 and 6 months later. vep and perimetry repeated 3 months after treatment.results: after 3 weeks, 3 and 6 months, bcva improved -0.32±0.40 logmar, -0.51±0.49 and -0.51±0.49, respectively (p=0.005, p=0.001 and p=0.001, respectively). vep recordings after 3 months, demonstrated -8.61±14.51 db mean decrease in implicit time (p=0.019). amplitude of voltage did not show significant difference with baseline (p=0.10). perimetry results after 3 months showed that mean deviation (md) improved 2.77± 3.94 db (p=0.016).conclusion: memantine resulted in significant improvement of bcva 3 weeks, 3 and 6 months after treatment of acute naion. memantine also resulted in significant decrease of implicit time and significant improvement of mean deviation in vep and perimetry after 3 months