Dina Motamedi1,2,3, Mahsa Mayeli1,2,3,4, Mahan Shafie1,2,3,4, Reza Sattarpour1,2,3, Maryam Rashidi Jazani5, Abbas Tafakhori5, Payam Sarraf6. 1. School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. 2. Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran. 3. NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran. 4. Department of Neurology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. 5. Tehran University of Medical Sciences, Tehran, Iran. 6. Department of Neurology, Imam Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran. p-sarraf@sina.tums.ac.ir.
Abstract
INTRODUCTION: As an inflammatory phenomenon, optic neuritis (ON) that causes demyelination in the optic nerve damages the retinal cells, and leads to visual impairment. Herein, we aimed to investigate the potential therapeutic effects of memantine on ON. METHODS: In this double-blinded randomized clinical trial, participants with the first episode of acute ON meeting the inclusion criteria were enrolled and were randomly divided into memantine group (MG; N = 20) and placebo group (PG; N = 18). Patients of MG received memantine for 6 weeks. The thickness of the retinal nerve fiber layer (RNFL), visual evoked potential (VEP), and visual acuity (VA) was measured in both groups at baseline and 3-month follow-up. RESULTS: Thirty-eight patients with ON were enrolled. In the follow-up, mean RNFL thickness of both groups significantly decreased in all quadrants (P < 0.001). Also, RNFL thickness of all but temporal quadrants were significantly higher in the MG than placebo. The reduction in RNFL thickness difference was insignificant between two groups in all but the inferior quadrant which was significantly lower in MG (P = 0.024). In follow-up, mean-to-peak of P100 of the affected eye were significantly lowered (P < 0.001). The changes in VEP were insignificant. Originally, the mean VA was 0.15 ± 0.08 and 0.17 ± 0.09 in MG and PG, respectively, but was improved significantly to 0.92 ± 0.06 and 0.91 ± 0.06 in MG and PG, respectively, in follow-up. CONCLUSION: Memantine can reduce the RNFL thinning in three quadrants by blocking NMD receptors. However, visual acuity did not show a significant difference between the two groups.
INTRODUCTION: As an inflammatory phenomenon, optic neuritis (ON) that causes demyelination in the optic nerve damages the retinal cells, and leads to visual impairment. Herein, we aimed to investigate the potential therapeutic effects of memantine on ON. METHODS: In this double-blinded randomized clinical trial, participants with the first episode of acute ON meeting the inclusion criteria were enrolled and were randomly divided into memantine group (MG; N = 20) and placebo group (PG; N = 18). Patients of MG received memantine for 6 weeks. The thickness of the retinal nerve fiber layer (RNFL), visual evoked potential (VEP), and visual acuity (VA) was measured in both groups at baseline and 3-month follow-up. RESULTS: Thirty-eight patients with ON were enrolled. In the follow-up, mean RNFL thickness of both groups significantly decreased in all quadrants (P < 0.001). Also, RNFL thickness of all but temporal quadrants were significantly higher in the MG than placebo. The reduction in RNFL thickness difference was insignificant between two groups in all but the inferior quadrant which was significantly lower in MG (P = 0.024). In follow-up, mean-to-peak of P100 of the affected eye were significantly lowered (P < 0.001). The changes in VEP were insignificant. Originally, the mean VA was 0.15 ± 0.08 and 0.17 ± 0.09 in MG and PG, respectively, but was improved significantly to 0.92 ± 0.06 and 0.91 ± 0.06 in MG and PG, respectively, in follow-up. CONCLUSION: Memantine can reduce the RNFL thinning in three quadrants by blocking NMD receptors. However, visual acuity did not show a significant difference between the two groups.