| Abstract [eng] |
The primary objective of this study was to compare laser and carbomer-induced high intraocular pressure models in Long Evans rats. Three experiments were performed during the study: the first experiment was aimed to determine the effective concentration of carbomer solution in a carbomer-induced high intraocular pressure model; the second experiment was performed to determine the effective number of laser shots in laser-induced high intraocular pressure model; and a third experiment demonstrated the efficacy of carbomer and laser-induced high intraocular pressure models with timolol administration. 4-5 months Long Evans rats were used in the study. Induction of 0.1% and 0.3% carbomer solution (20μl) into anterior chamber of rats was performed in order to induce high intraocular pressure model of carbomer. In order to induce laser high intraocular pressure model 50, 100, 200, or 400 laser shots were performed into the episcleral veins of rats. In order to determine the efficacy of both high intraocular pressure models, timolol (10 μl) was administered daily three times per day (8 am., 12 pm., and 5pm.). IOP measurements with tonometer were performed almost every day during all experiments, and the number of retinal ganglion cells was counted at the end of the study. The study results showed that 0.3% carbomer solution injections in the carbomer-induced high intraocular pressure model, and 400 laser shots in the laser-induced high intraocular pressure model were the effective choice in order to increase intraocular pressure and to reduce retinal ganglion cell number. In carbomer-induced high intraocular pressure model, timolol treatment was effective in preventing an increase in IOP and a decrease in RGC, but in the laser-induced high intraocular pressure model, timolol treatment was not significant. Comparison of laser and carbomer-induced high intraocular pressure models in Long Evans rats showed that both models were successful in increasing intraocular pressure and reducing retinal ganglion cell number. However, the carbomer-induced high intraocular pressure model is a less expensive, no-equipment required method in which increased IOP persists for a longer period of time, only a single procedure is needed to induce the model, and treatment with timolol is successful. |
