Contrast-Sensitivity Function and Photo Stress-Recovery Time in Prediabetes

The purpose of this study was to assess contrast sensitivity and macular function test in prediabetes.

Participants aged 25-45 years with or without diabetes were enrolled and classified as normal, prediabetic, and diabetic based on their HbA_1C values. They underwent a comprehensive eye examination, and those with diabetic retinopathy, cataract, glaucoma, and high myopia were excluded. Participants with best-corrected visual acuity of 0 logMAR were included. Contrast-sensitivity function (CSF) was measured using a Pelli-Robson chart, and photo stress-recovery time (PSRT) assessed using direct ophthalmoscopy for the 70 eligible participants. Mean values were compared among the three groups.

This was a cross-sectional observational study.

In the 70 participants, mean CSF was 1.71±0.10, 1.64±0.11, and 1.61±0.08 log units in the normal, prediabetic, and diabetic groups, respectively (p<0.001). Similarly, PSRT was found to be 35.80 seconds, 41.63 seconds, and 47.77 seconds in the normal, prediabetic, and diabetic groups, respectively (p<0.001).

The data suggested that reduced CSF and delayed PSRT seen in subjects with prediabetes could give valuable clinical insight into early changes before diabetes and microvascular damage is incurred. A future study with a larger sample could help substantiate the results.