Purpose: Can oscillatory potentials be a useful method for detection of retinal dysfunction in insulin-dependent diabetics without retinopathy?
Material and methods: In this study scotopic oscillatory potentials (OPs) were obtained in 35 subjects (70 eyes) with insulin-dependent diabetes without retinopathy (mean disease duration--5 years) and in 15 healthy subjects (30 eyes). This examination was performed according to the recommendations of the International Society of Clinical Electrophysiology of Vision (ISCEV). The oscillatory potentials were extracted from the maximal combined response by high-pass filtering. We analysed amplitude and peak-latencies of the first three electroretinographic oscillatory potentials O1, O2, O3, index of wavelets [sum of amplitudes (O1 + O2 + O3)] and compared with the results of the control group.
Results: In group of patients with insulin-dependent diabetes without retinopathy, we received statistically significant reduction of amplitude O1 (p < 0.003) and index of wavelets (p < 0.04). Reduced amplitude O1 was obtained in 10%, index of wavelets in 31.4% of analysed eyes. We didn't observe statistically significant changes in amplitudes O2, O3 and latencies O1, O2, O3.
Conclusions: Our results suggest that retinal dysfunction is present in insulin-dependent diabetics without retinopathy 5 years after onset of the disease. The sum of amplitudes (O1 + O2 + O3) was the most sensitive parameter of retinal abnormalities. It seems reasonable to have more frequent ophthalmological examination of the diabetics with abnormal oscillatory potentials.