The occurrence of cataract in rats fed on diets deficient in vitamin B2

DAY et al. [1931] in America first reported that they had obtained cataract in albino rats by feeding a diet deficient in vitamin B2.The ration used was that of Sherman and Spohn [1923] which has been widely employed in work with this vitamin.Cataracts were produced in 92 % of rats after an average period of 72 days.The work was developed by Langston et al. [1933] and by Langston and Day [1933] who observed an equally high incidence of cataract in mice and in young wild gray rats deprived of vitamin B2.By feeding diets deficient in vitamin B2 Day, Langston and Cosgrove [1934] obtained cataract in rats and chickens and Day [1934] reported cataract in rats, mice, chickens and monkeys.The im- portance of cataract as a symptom of vitamin B2 deficiency was stressed by these authors.Day and Langston [1934] published further evidence that in nearly all the cases examined rats receiving a diet free from vitamin B2 developed cataract.They found that the appearance of cataract was delayed where small but in- sufficient amounts of vitamin B2 were given; and the delayed appearance of cataract was correlated with the growth-rate data.It was concluded that cataract was probably a better criterion of vitamin B2 deficiency than was dermatitis.These observations are of great interest since they are related to the problem of the aetiology of cataract as well as to that of vitamin deficiency.It is im- portant that it should be established beyond doubt whether or not degenerative changes in the eye-lens can be produced by the omission of a specific substance, such as a vitamin, from the diet.It is equally important from the point of view of vitamin studies to know if cataract, which can readily be observed, is in fact a consistent symptom of a vitamin deficiency.In addition a technique for pro- ducing cataract regularly in a laboratory animal by dietary control would prove most useful in further studies in the aetiology of cataract.For these reasons it was considered advisable to attempt to repeat the work of Day and his colleagues.Experiments were therefore undertaken in which diets deficient in vitamin B2, including the Sherman and Spohn [1923] diet as used by the American workers, were fed to rats and the eyes examined with an ophthalmoscope at weekly intervals.The results of these experiments form the subject of the present communication.EXPERIMENTAL.Thirty-six young black and white rats of about 70 g.weight were obtained from a commercial source and kept in single cages with wire screen bottoms.The Sherman-Spohn [1923] diet was fed.