Touch-perception thresholds in blind diabetic subjects in relation to the reading of Braille type.

Abstract

Many diabetic blind persons experience difficulty in reading Braille. This contrasts with clinical experience that diabetic neuropathy does not affect the hands. Accordingly, touch-perception thresholds were measured in 10 healthy seeing, 10 nondiabetic blind and 10 diabetic blind subjects. There were no differences in the thresholds for light touch, light contact vibration and two-point discrimination between the seeing and the nondiabetic blind subjects. In all the diabetic blind subjects the perception threshold for each of these modalities was increased. In two the abnormalities reached the level of awareness. Since the distance between the points in English Braille type is 2.2 mm, the difficulty of the diabetic subjects in reading Braille is probably related to an inability to perceive the individual points clearly. In the nondiabetic subjects the mean threshold for two-point discrimination was 1.6 mm whereas in the diabetic blind subjects it was 2.5 mm.