Efficacy of memantine in acute non-arteritic ischemic optic neuropathy

ABSTRACT

Evaluation of efficacy of Memantine [N-Methyl-D-Aspartate Receptor Antagonist] on visual function of patients with acute non-arteritic ischemic optic neuropathy [NAION]. 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. 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]. 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