Object: experimental cataract, ocular hypertension. Purpose: to define in an experiment the role of ocular hypertension in the pathogenesis of light-induced cataract and to substantiate the use of carnosine in the prevention and treatment of pathological changes in the lens in the presence of increased intraocular pressure. Methods: experimental, ophthalmic, biochemical. Statistical methods for data processing of all experimental findings, parametric and nonparametric, using the SPSS 11 package and Statistica 5.5. The cocataractogenic effect of ophthalmic hypertension on the development of cataracts in an experiment (model of light cataract) was proved for the first time. It is established that in the conditions of high intraocular pressure clouding of the lens and the formation of light cataracts develops faster and with more pronounced manifestations than in the absence of ophthalmic hypertension. Thus, when exposed to light, the first changes in the transparency of the lenses were observed after the 10th week of the experiment. During this period, 33,3% of the eyes were detected in the initial stages of opacity (stages I-II), the rest remained transparent. Light irradiation on the background of high intraocular pressure caused changes in the lenses from 5 weeks of observation, and at 10 weeks 50% of the lenses had stage IV-V turbidity. Еnhanced scientific data on the participation of oxidation and peroxidation processes in the initiation of mechanisms of pathogenic effects of high intraocular pressure on the lens of animals. New scientific data on the negative effect of ophthalmic hypertension on the state of the enzymatic antioxidant system and the reducing potential of thiol compounds of the lens in the simulation of light cataracts have been obtained. It was found that the level of reduced glutathione in the lens of these animals after 10 weeks was 81,1%, oxidized glutathione 122,4%, enzyme activity was for glutathione peroxidase – 79,8%, superoxide dismutase – 82,1%, catalase - 80% relative to the group only with light exposure (p<0,05). For the first time it was found that the use of carnosine in the simulation of light cataracts on the background of ophthalmic hypertension caused a decrease in the accumulation of LPO products and protein oxidation (reduction of malonic dialdehyde by 32,3%; increase in thiol groups of proteins by 40,7%, p<0,05), an increase in the level of reduced glutathione (by 49,2%, p<0,05), activation of antioxidant enzymes (glutathione peroxidase by 37,4%, superoxide dismutase by 37,2%, catalase by 31,7%, p<0,05). It was proved for the first time that the metabolic correction of the detected optical and pathochemical disorders of the lens by the compound carnosine causes an increase in the resistance of the lens to the action of cataractogenic factors in ophthalmic hypertension. In the simulation of light cataract on the background of ophthalmic hypertension, carnosine slowed down the development of lens transparency disorders. The number of lens with stage V turbidity in animals treated with carnosine after 10 weeks of the experiment was twice less than in animals with the same pathogenic effects, but without the use of the drug. After 20 weeks, the maximum stage VII of lens clouding was observed in 16,7% and 30,0%, respectively (p<0,05). A scientific and experimental substantiation of the expediency of carnosine for the prevention of pathological changes in the lens during the development of light cataracts on the background of ophthalmic hypertension and the possibility of correcting the imbalance of the prooxidant-antioxidant system in the tissues of the eye of animals. Based on the obtained data, the tactics of treatment can be improved by including carnosine in the complex therapy of patients with the initial stage of age-related cataract, which developed in primary open-angle glaucoma, which will significantly increase the drug efficacy of treatment. As prevention of development of pathological changes of optical properties and metabolic disturbances in a lens at ophthalmic hypertension it is expedient to offer restriction of light loadings on an organ of sight in combination with systematic course reception of carnosine. The results of the work are introduced into the lecture course of training of interns, clinical residents and cycles of advanced training of ophthalmologists of the SI "The Filatov Institute of Eye Diseases and Tissue Therapy NAMS of Ukraine" and are used in the scientific and pedagogical work of the Department of Human and Animal Physiology of Odesa I. Mechnikov National University. Scope - medicine, ophthalmology.
