Lenticular Effects of Parathyroid Hormone

¹ Department of Ophthalmology, New York University School of Medicine, New York, N. Y.

It has been known for some time that individuals with hypoparathyroidism tend to develop cataracts. The formation of cataracts after experimental parathyroidectomy has also been reported. In view of the known effects of parathyroid hormone upon carbohydrate metabolism, and the relationship between defects in carbohydrate metabolism and cataract formation, the possibility that parathyroid hormone might have a direct effect upon carbohydrate metabolism in the lens was investigated. After parathyroidectomy, the ability of the lens to utilize glucose and to produce lactic acid was reduced. The addition of parathyroid, hormone in vitro restored these processes to normal. The results indicate that carbohydrate metabolism in the lens is under direct control of the parathyroidhormone. The implications of these findings for the genesis of cataracts in hypoparathyroidism is discussed.