EN
Purpose: Oxidative mechanisms play a major role in the etiology and pathogenesis of cataract, especially age-related cataract (ARC). Our study aimed to investigate the serum vitamin E level and the activities of systemic antioxidant enzymes: superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the blood of dogs with age-related cataract but without any general diseases. Material and methods: The population examined consisted of 40 dogs of various breeds and both sexes, aged 10-16 years, diagnosed with age-related cataract. Cataract was diagnosed by complete ocular examination. Blood was collected during clinical examination from the external jugular vein in dogs weighing less than 20 kg or from the small saphenous vein in dogs weighing over 20 kg. The control group consisted of 10 healthy dogs of different breeds and sexes, aged 8-12 years, without cataract. SOD and GPX were measured by a colorimetric reagent kit Randox SOD and Randox GPX. The level of vitamin E was determined using a Perkin-Elmer LS 30 luminescent spectrometer. This apparatus determines the vitamin E level by the fluorometric method of Hansen and Warwick . Results: The results showed a significantly lower activity of SOD as well as a lower activity of GPX and a lower level of the vitamin E in dogs with ARC compared to healthy dogs. Conclusions: The results obtained indicate a weakening of the general antioxidant defence system in the course of ARC in dogs. These results suggest that such conditions may have effect on the development of canine age-related cataract and are consistent with the free radical theory of age-related cataract development.