Corneal sensitivity and vibratory perception in diabetes mellitus

36 patients suffering from diabetes mellitus and 45 controls were subjected to blind studies for corneal sensitivity using Cochet & Bonnet's aesthesiometer and of vibratory perception of the left index finger and great toe by biothesiometer. 83% of the diabetics had a corneal sensitivity below 60 mm against 38% of the controls. Likewise a significantly reduced vibratory perception was noticed among the diabetics. Further, the reductions of corneal senstivity and vibratory perception were correlated in the diabetics. In both groups falling corneal sensitivity and vibratory perception were found with increasing age over and above 50 years. There is evidence to suggest that a reduced corneal sensitivity in relation to diabetes mellitus forms part of a polyneuropathy.