Neuroprotective effect of systemic and/or intravitreal rosuvastatin administration in rat glaucoma model

To evaluate the neuroprotective effect of rosuvastatin, in a rat experimental glaucoma model. Ocular hypertension was induced in right eyes of Long-Evans rats (n=30) by cauterization of three episcleral veins. Left eyes were defined as controls. Rats were divided into five groups: oral rosuvastatin, intravitreal rosuvastatin, oral+intravitreal rosuvastatin, intravitreal sham and glaucoma without intervention. Rats were sacrificed at day 14. Retinal ganglion cell (RGC) number was assessed by histopathological analysis. Terminal deoxynucleotidyl transferase-mediated dUTP-nick end-labeling (TUNEL) staining and the expression of glial fibrillary acidic protein (GFAP) in RGC layer was also examined. A significant intraocular pressure (IOP) elevation was seen (P=0.002). Elevated IOP resulted in a significant decrease in number of RGCs in group 5 (70.33±8.2 cells/mm(2)) when compared with controls (92.50±13.72 cells/mm(2); P=0.03). The RGC number in group 1 (92.4±7.3 cells/mm(2)) was significantly higher than group 5 (P=0.03). The numbers of RGC in groups 2, 3 (57.3±8.2 cells/mm(2), 60.5±12.9 cells/mm(2)) were comparable with that of group 5 (P=0.18 and P=0.31). The apoptosis rates with TUNEL staining were also parallel to RGC number. Animals with experimentally induced glaucoma showed an increase in retinal GFAP immunoreactivity. Decrease in RGC loss and apoptosis suggest the neuroprotective potential of oral rosuvastatin treatment in a rat model of ocular hypertension. However intravitreal rosuvastatin showed a contrary effect and further studies are required.