Differential diagnostic criteria for changes in the anterior segment of the eye in dogs with different forms of glaucoma

Abstract

The research goal was to describe the manifestations of different types of canine glaucoma by analyzing the clinical picture depending on its form and stage of pathogenesis. The study evaluated the clinical picture of hypertensive glaucoma in 30 dogs based on Department of Veterinary Surgery of the Moscow State Academy of Veterinary Medicine and Biotechnology - MVA named after K.I. Skryabin and the Center of Emergency Veterinary Ophthalmology and Microsurgery. Special attention was paid to such symptoms as: degree of intraocular pressure increase, lacrimation of the eyes, congestive injection of conjunctival vessels, episcleral edema, mydriasis, buphthalmos, anisocoria, corneal edema, signs of blindness, pain syndrome, photophobia, lens subluxation, blepharospasm, variable changes of the retina and optic disc. Quantitative data were processed using Microsoft Excel 2016. The secondary closed-angle form was registered more often (in 56.6% of cases) in the form of chronic malignant ophthalmic hypertension not amenable to therapy (in 46.6% of cases). The degree of intraocular pressure elevation ranged from moderately elevated to high. Significant differences were found between forms of hypertensive glaucoma in dogs, such as primary open-angle and secondary closed-angle, in the incidence of photophobia, blepharospasm, and goniosynechia. Significant differences between the stages of disease pathogenesis (acute and chronic ophthalmic hypertension) were also revealed in the frequency of high intraocular pressure, lacrimation, congestive injection of conjunctival vessels, episcleral edema, anisocoria, pain syndrome, photophobia, blepharospasm. Significant differences were also found between such stages of the disease pathogenesis as chronic and malignant ophthalmic hypertension in the frequency of high intraocular pressure, buphthalmos and signs of visual impairment. The majority of dogs in the analyzed sample showed secondary closed-angle form in the terminal stage. In primary open-angle glaucoma, elevated intraocular pressure was recorded in a higher proportion of cases, whereas in primary closed-angle glaucoma and secondary closed-angle glaucoma, high intraocular pressure was recorded in a higher proportion of cases. The symptoms of hypertensive glaucoma have a greater variability and appear in a greater proportion of dogs of the analyzed sample in chronic malignant ophthalmic hypertension that is not amenable to therapy.