Retina-Vitreous
2012 , Vol 20 , Num 3
Neuroprotective Effect of Memantine and Hyperbaric Oxygen Therapy After Acute Ischemia-Reperfusion Injury: Immunohistochemical Analysis
1M.D., Akyazı State Hospital, Eye Clinic, Sakarya/TURKEY2M.D., Bakırköy Training and Research Hospital, Eye Clinic, İstanbul/TURKEY
3M.D. Professor, Kafkas University Faculty of Medicine, Department of Ophthalmology, İstanbul/TURKEY
4M.D. Asistant Professor, Yeditepe University Medical Faculty, Department of Histology, İstanbul/TURKEY
5M.D., Yeditepe University Medical Faculty, Department of Histology, İstanbul/TURKEY
6M.D. Asistant Professor, Kafkas University Faculty of Medicine, Department of Ophthalmology, İstanbul/TURKEY
7M.D. Professor, İstanbul University, İstanbul Medical Faculty, Department of Underwater Medicine and Hyperbaric Medicine, İstanbul/TURKEY Purpose: This study applies treatment methods to rat retina subjected to acute ischemia-reperfusion injury and compares by histopathological examination the efficacy of Memantine and hyperbaric oxygen therapy.
Material and Methods: Twentyfour adult Wistar albino rats were divided into four groups after retinal ischemia was induced by elevating the intraocular pressure to 120 mmHg. The groups were: Group 1: Control group, right eyes were cannulated with a 30 gauge needle and removed without causing any intraocular pressure change. Group 2: Memantine treatment group, animals were given single dose of intravenous 25 mg/kg Memantine by tail vein route after inducing acute retinal ischemia. Group 3: Hyperbaric oxygen (HBO) therapy group, in two hours following acute retinal ischemia HBO treatment was applied for nine days. Group 4: Acute retinal ischemia model but without treatment (ARI).
Results: Twenty-one days after establishing ischemia- reperfusion, the right eyes were enucleated after cardiac glutaraldehyde perfusion method, and then submitted to histological evaluation. In average, the total retinal ganglion cell count (RGCC) was 239.93±8.60 in control group; 125.14±7.18 in ARI group; 215.89±8.36 in Memantine group and 208.69±2.05 in HBO group. Mean apoptotic index in groups were 0.03±0.02; 0.5±0.03; 0.22±0.05 and 0.08±0.03 respectively.
Conclusion: The present study shows that Memantine and HBO therapy was effective in reducing the damage induced by acute ischemia-reperfusion in rat retina. Our study suggests that these treatments had beneficial effects due to neuroprotection,and therefore may be applied in clinical practice. Keywords : Acute retinal ischemia model, memantine, hyperbaric oxygen therapy, retinal ganglion cell counts, apoptotic index