Cataract in Rats Fed on High Lactose Rations

Abstract

Mature bilateral cataract has occurred in 68 per cent of rats fed on a 70 per cent lactose ration with advanced lens changes showing in 100 per cent of the animals. Rations containing lower quantities of lactose resulted in slower development or less pronounced type of lens change. Cataracts have never appeared in rats fed starch, maltose, dextrin or sucrose, respectively, as the sole source of carbohydrate at the 70 per cent level. The progressive lens changes have been described in detail. The developing opacities give the histological picture of human cataract. Blood, urine, and tissue analyses on a limited number of animals indicated some disturbance in both carbohydrate and mineral metabolism with a loss of galactose in urine. The calcium content of cataractous eyes doubles the normal. The total and diffusible calcium content of blood serum did not seem to be significantly altered. The possibility of producing or controlling the development of cataract in lower animals by dietary means promises to be a valuable device for further and more detailed study of the etiology of cataract.