Stability of lysosomal membranes of ocular neuronal structures in the rabbit model of glaucoma in the presence of experimental diabetes mellitus

Background: Pathogenetic mechanisms of glaucoma remain largely poorly understood. Some authors consider diabetes as a major risk factor for glaucomatous damage. Determination of the state of lysosomal membranes of the retina and optic nerve in primary glaucoma associated with diabetes is important for establishing the pathogenesis of this combined disorder. Purpose: To investigate the structural and functional stability of lysosomes in a rabbit model of experimental glaucoma (ocular hypertension) associated with streptozotocin-induced diabetes. Materials and Methods: A total of 34 adult rabbits were used in the study to model streptozotocin-induced diabetes only, glaucoma (ocular hypertension) only or glaucoma associated with diabetes. The activity of the marker lysosomal enzyme, acid phosphatase, was determined in the retinal and optic nerve tissue. Results: Stability of lysosomal membranes in the neuronal ocular tissue was found to be sharply decreased in the model of glaucoma associated with diabetes. The activity of the marker lysosomal enzyme, acid phosphatase, changed more markedly in the model of glaucoma associated with streptozotocin-induced diabetes than in those of diabetes only or glaucoma only. Conclusion: Lysosomal dysfunction is a pathogenetic phase of the glaucomatous process in the presence of diabetes mellitus