Protective effectiveness of isradipine in experimental ganglion cell damage

Glaucoma is a progressive optic neuropathy characterised by retinal ganglion cell loss. Glaucoma is the second most common cause of preventable blindness in the world. Although the only proven modifiable risk factor is intraocular pressure, vision loss due to glaucoma can occur even if intraocular pressure is normal. Neuroprotective therapy may be useful in glaucoma. Isradipine is an L-type calcium channel blocker used as an antihypertensive. It has neuroprotective and antioxidant activity. In this study, we planned to investigate the neuroprotective and antioxidant efficacy of isradipine topical drops in experimental ganglion cell injury, which has not been studied in eyes before. In our study, 60 Wistar albino rats were randomly divided into 6 groups. Seven rats were included in the control group and control group was not treated. Seven rats were included in the Sham 1 group and Sham-1 group received dimethyl sulfoxide (DMSO) intravitreally, which was used as solvent in the preparation of the drugs. Seven rats were included in the Sham-2 group and apoptosis was induced by injection of N-methyl-D-aspartate (NMDA) and retinal ganglion cell damage is aimed to provide. There were 13 rats each in isradipine-1, isradipine-2 and brimonidine groups and and apoptosis was induced by injection of N-methyl-D-aspartate (NMDA) and retinal ganglion cell damage is aimed to provide. Sham-1 and sham-2 groups did not receive any treatment. Isradipine-1 group received 0.03% topical isradipine drops, isradipine-2 group received 0.06% topical isradipine drops, and brimonidine group received 0.15% brimonidine tartrate drops at 12-hour intervals for 21 days. Caspase 3 level was significantly lower in isradipine-1 and isradipine-2 groups compared to the other groups. Glutathione peroxidase enzyme levels in isradipine-1 and isradipine-2 groups were at a statistically insignificant level higher than the other groups. Superoxide dismutase enzyme levels were significantly higher in isradipine-1 and isradipine-2 groups compared to the other groups. Catalase enzyme level was significantly lower in the isradipine-2 group compared to the other groups. In isradipine-1 and isradipine-2 groups, BDNF levels were increased at a non-statistically significant level compared to sham-2 and control groups. In histological evaluation, isradipine-2 group was found to be statistically significantly higher than sham-2 and brimonidine group in terms of retinal ganglion cell number at 100 µm retinal length. Topical isradipine drip increased the survival rate of retinal ganglion cells by showing antiapoptotic and antioxidant effects.