Effects of Memantine on Visual Functions after Scleral Buckling for Retinal Detachment

Purpose: Evaluating the effects of memantine on visual function after scleral buckling for rhegmatogenous retinal detachment (RRD) Methods: In a Double blind prospective randomized clinical trial, 61 patients with clinical diagnosis of less than 4 weeks macula-off RRD who had successful scleral buckle surgery had been selected and divided into two randomized groups. Thirty of them received 5 mg/day memantine orally for first week and 10 mg/day for two weeks, while the others (31 patients) received placebo. Best corrected visual acuity (BCVA), macular thickness measured by optical coherence tomography (OCT) and contrast sensitivity test, were measured for all patients at one and three months. Multifocal electroretinography (ERG) was performed for all patients who returned to us at third month postoperatively. Results: Mean BCVA was 0.74±0.27 logMAR in memantine group versus 0.77±0.21 logMAR in placebo group at one month, and improved respectively to 0.64±0.25 logMAR versus 0.69±0.26 logMAR in memantine and placebo groups. There wasn't significant difference in first month and third month BCVA between two groups. Mean central macular thickness in memantine group was significantly lower than placebo group 215±41 μm versus 262±101 μm at first month, respectively and this difference was also significant after three months 204±39 μm versus 249±57 μm. Nineteen of 61 patients (31.4%) had persistent subretinal fluid (SRF) at first month (12 of them were in placebo group). P1 wave amplitude of multifocal ERG in 10-15o and >15o of central fovea in memantine group were significantly higher than placebo group. Conclusion: Memantine using as an adjuvant to reattachment surgery may have neuroprotective effects which can rehabilitate the function of macula in RRD patients.