RESUMO
Biochemical evidence on lens culture suggests that antioxidant nutrients can protect lens against peroxidation caused by radiation. A case-control study was carried out on 262 middle aged (45-54) and aged (55-64) subjects. The relationship between biochemical markers of antioxidant status and senile lens changes (including cataract) was examined in 131 subjects with senile lens changes and 131 control subjects with clear lens. Antioxidant status was measured using plasma and erythrocyte glutathione peroxidase, erythrocyte superoxide dismutase and catalase activity and plasma levels of vitamin E and vitamin A. Subjects were grouped by age and sex. The results were as follows: (1) The subjects with lens changes tended to have lower plasma levels of vitamin E and vitamin A, lower activity of several antioxidant enzymes and higher level of MDA. (2) The subjects with senile lens changes had significantly lower erythrocyte glutathione peroxidase level. (3) In the middle-aged group, subjects with senile lens changes were observed to have lower erythrocyte and plasma glutathione peroxidase level than those without senile lens changes. The results suggest that appropriate amount of antioxidant nutrients might be expected to prevent or retard the process of lens changes.
Assuntos
Envelhecimento/metabolismo , Antioxidantes/metabolismo , Catarata/metabolismo , Micronutrientes/farmacologia , Estudos de Casos e Controles , Catalase/sangue , Catarata/epidemiologia , Catarata/prevenção & controle , Feminino , Glutationa Peroxidase/sangue , Humanos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Prevalência , Vitamina E/sangueRESUMO
The results of ophthalmic examination of 413 workers exposed to TNT were analysed. Cataracts were detected in 143 cases (34.6%), reaching 88.4% in those exposed in excess of 20 years. Both prevalence and degree of lenticular damage increased with increasing exposure. The shortest latent period of cataract development was three years and the youngest subject was only 22 years old. The characteristics of TNT lens impairment are: (1) gray-yellow dot opacities, with circular and cuneiform in the peripheral part of the lens detectable with transillumination and slit-lamp; (2) circular, discal or petaline opacities in the central part of the lens; (3) a transparent zone between the circular shadow and the lens equator. While circular opacities were observed in early cases, cuneiform opacities occurred in later cases.