[Effect of induced hyperglycemia on contrast sensitivity function in insulin-dependent diabetic patients]

Acute hyperglycemia in diabetes mellitus is often associated with transient subjective visual disturbances that have not yet been objectively evaluated. We used a contrast sensitivity (CS) test to assess functional visual disturbances in provoked hyperglycemia in 20 patients with well-controlled insulin-dependent diabetes (40 eyes) with no evidence of diabetic retinopathy and with intact visual acuity (age: 32 +/- 8.2 years, duration of diabetes: 11.4 +/- 7.3 years). The CS function was measured by using the CSV-1000 CS test, which is rapid and easily comprehended by the patient and encompasses four spatial frequencies, 3 (A), 6 (B), 12 (C) and 18 (D) cycles/degree. At each frequency, eight pairs of circular targets differing stepwise in contrast were presented simultaneously. The number of targets seen by each patient in the four spatial frequencies at euglycemic (116 +/- 14.7 mg/dl) and hyperglycemic (274 +/- 52 mg/dl) levels, expressed as the CS score, was recorded and afterwards analyzed. The differences in mean CS scores at the individual frequencies at euglycemic versus hyperglycemic levels were statistically significant (p < 0.001). Visual acuity remained stable during hyperglycemia. There was no significant difference in the amount of CS reduction between the group of patients that had had diabetes for a duration of more than 10 years and the group who had had diabetes for less than 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)