Abstract
Purpose::
To evaluate the increment amplitude of the 30-Hz flicker electroretinogram (ERG) recorded during light adaptation in patients with diabetes mellitus (DM).
Methods::
Subjects were 27 eyes of 27 patients with DM (mean age, 60.4±9.8 y.o.) and 10 normal eyes of 10 control subjects (mean age, 63.6±5.5 y.o.). Eyes with DM were divided into 4 groups according to the degree of diabetic retinopathy (DR): (1) NDR group (10 eyes; mean age, 63.6±5.2 y.o.): no DR was seen. (2) SDR group (7 eyes; mean age, 61.6±9.8 y.o.): simple DR. (3) PPDR group (4 eyes; mean age, 53.8±19.0 y.o.): pre-proliferative DR. (4) PDR group (6 eyes; mean age, 58.3±7.2 y.o.): proliferative DR. Subjects were given 30 minutes before examination for dark adaptation. With a background light of 25 cd/m2, 30-Hz flicker ERG was subsequently recorded at 5 various points, namely, 0, 5, 10, 15 and 20 minutes after starting light adaptation and the amplitudes were assessed.
Results::
The ratio of the amplitude at 20-minute to 0-minute after light adaptation was 2.26±0.76 in normal subjects. In diabetic patients, it was 1.50±0.46 in NDR group, 2.00±0.68 in SDR group, 1.82±0.45 in PPDR group, and 1.60±0.30 in PDR group. The ratios of the amplitudes in those 4 diabetic groups were found smaller than that in the normal subjects.
Conclusions::
These results suggested the disturbance of light adaptation in diabetic patients.
Keywords: diabetic retinopathy