Diabetic keratopathy as a manifestation of peripheral neuropathy.

In a study of 102 patients (64 women and 38 men; 63 whites and 39 nonwhites; 77 with adult-onset disease and 25 with juvenile-onset disease), the data, after being adjusted for age, showed that diabetic peripheral neuropathy was associated with diabetic keratopathy. The strongest predictor of both keratopathy and corneal fluorescein staining was vibration perception threshold in the toes (P less than .01); the severity of keratopathy was directly related to the degree of diminution of peripheral sensation. Other predictors of keratopathy were reduced tear break-up time (P less than .03), the type of diabetes (P less than .01), and metabolic status, shown by fasting C-peptide levels (P less than .01). No significant relationships were found between keratopathy and tear glucose levels, endothelial cell densities, corneal thickness, or duration of disease.