The prevalence of cataract in insulin-dependent and non-insulin-dependent-diabetes mellitus.

In an epidemiological study of 533 diabetics - 227 treated with insulin and 306 treated with oral hypoglycaemic agents (OHA) - the prevalence of cataract/aphakia and lens opacities was in total higher (P less than 0.01) in type 2 diabetics (= non-insulin-dependent diabetes) compared with type 1 diabetics (= insulin-dependent diabetes). Type 2 diabetics were characterized by a higher age than type 1 diabetics (P less than 0.01). Thus, an age-specific comparison between type 1 and type 2 diabetics showed no difference (P greater than 0.05) in the occurrence of cataract/aphakia in type 1 diabetics (P less than 0.01) in the age interval 50-64 years. Cataract/aphakia and lens opacities correlated positively (P less than 0.01) with the current age and presence of retinopathy within both groups of diabetics. In type 1 diabetics the duration of diabetes was related to cataract/aphakia. A comparison of this study with the results of previous population studies of cataract in non-diabetics indicates that cataract/aphakia occurs more frequently in diabetics exclusively below the age of 65-70 years.