Clinical, ophthalmological and morphological characteristics of cat ophthalmopathy associated with paraneoplastic syndrome

Abstract

This paper discusses a scientifically based approach to the study of differential diagnostic criteria, features of the development and course of the pathological process and morphological characteristics of cat ophthalmopathy associated with paraneoplastic syndrome. The research was conducted from 2022 through 2024 at the Laboratory of Animal Oncology, Ophthalmology and Biochemistry and the Department of Pet, Laboratory and Exotic Animal Diseases of the Russian Biotechnological University. We used a comprehensive methodological approach including clinical, laboratory, instrumental and morphological research methods. The research targets were 324 animals with oncological pathologies of various histogenesis. As a result of a comprehensive ophthalmological study in 64 cats (19.7% of cases), ophthalmopathy associated with paraneoplastic syndrome were revealed; other possible causes of pathological changes in the organ of vision were excluded during a comprehensive examination of animals. We found out the main clinical signs of cancer associated with ophthalmopathy manifested in the form of inflammatory processes in the uveal tract of the eye with a predominance of forms of endogenous chorioretinitis (71.9% of cases, 46 cats), total uveitis (21.9% of cases, 14 cats), less often iridocyclitis (6.2%, 4 cats) which indicated a violation of the hematophthalmic barrier of a presumably immune nature. The differential diagnostic criteria of paraneoplastic ophthalmic syndrome include: opalescence of moisture in the anterior chamber of the eye (48.4%), mydriasis (68.8%), decreased pupil response (37.5%), clouding of the lens (51.6%), opacity of the vitreous body (65.6%), hemorrhages on the fundus (32.8%), the presence of foci hyporeflexia (20.3%) and hyperreflexia of tapetum (32.8%). Histological study of enucleated eyes revealed in 66.7% of cases cystic cavities in the iris filled with eosinophilic substance, vasodilation of the choroid and accumulation of inflammatory exudate, in one case signs of chronic retinal detachment were observed.