Twenty-seven subjects having vitreous asteroid bodies were matched for age and sex with control subjects. The results of random blood glucose analysis and 2-hr glucose tolerance tests were used to determine the presence of diabetes mellitus or impaired glucose tolerance. Five of the subjects having asteroid bodies were diabetic and four had impaired glucose tolerance. In the control group there were no diabetics; however, three subjects had impaired glucose tolerance. These results confirm that a relation exists between the occurrence of vitreous asteroid bodies and diabetes mellitus (p = 0.036). There was no statistically significant difference between random blood glucose levels of the two cohorts. Four of the five diabetics were excluded from the 2-hr glucose tolerance tests; however, for the remainder of the asteroid body group, there was no significant difference in the results of this test compared with the control group. These results suggest that the relation between asteroid bodies and diabetes may not be dependent on blood glucose levels. Diabetics having asteroid bodies may form a special subgroup of the disease in which there is accelerated degeneration and mineralization of collagen associated with increased intraocular vascular permeability.