Design and analysis of an efficient glaucoma model for evaluation of pharmacological trials

Abstract

Glaucoma is a multifactorial progressive optic neuropathy whose main risk factor is intraocular hypertension (IOH). It generates loss of nerves and is the primary cause of irreversible blindness worldwide. The objective of this work was to develop a glaucoma model in rabbits and analyze the anatomical, functional and biochemical changes over time through intraocular pressure (IOP), electroretinography (ERG), antioxidant capacity with FRAP essay. in aqueous humor (AH), and histopathology with quantification of retinal ganglion cells (RGC). 24 female New Zealand white rabbits were used. In 12 animals, glaucoma was induced by injection of µ-chymotrypsin. During the postoperative period, the treatment and control groups were examined weekly. 7 days after surgery, IOP (mmHg) was 18.30 ± 1.75 in the treatment group and 13.59 ± 0.63 in the control (p<0.02). The most important rise was at 14 days (treatment 27 ± 2.64 vs. controls 15.78 ± 0.86) (p<0.001), remaining stable thereafter. In the ERG, the analysis of the latency of A and B waves in ms with stimulus intensity of 15 LUX showed a difference between treatment and controls (p ≤ 0.05). The FRAP values (mM FeSO4/mg of proteins) were 520.3 ± 44 in the treatment group, and 2851.3 ± 178.7 in the control (p<0.0001). The RGC count per field was 15 ± 2.20 in the control group and 5.52 ± 0.77 in the treatment group (p<0.001). The glaucoma model enabled the analysis of anatomical, functional and biochemical changes as a function of time.