Electrophysiological studies in newly onset type 2 diabetes without visible vascular retinopathy

Abstract

The purpose of this study was to investigate the early alterations of retinal function, assessed with electrophysiology, in newly onset type 2 diabetes patients without vascular retinopathy. Seventeen patients with newly diagnosed type 2 diabetes (duration 7±3 months), without any vascular retinopathy in fundus photographs, were examined with full-field electroretinogram (ERG) and multifocal ERG (mfERG). The results were compared with those of age-matched subjects without diabetes. In the dark-adapted full-field ERG, the a-wave and the 30-Hz flicker implicit times were delayed in diabetes patients compared to controls, P=0.001 and P=0.020. In the first-order kernel of the mfERG, the first positive wave, P1, was delayed in all areas measured. The electrophysiological examinations demonstrate early alterations of retinal function characterised by a delayed a-wave implicit time in the dark-adapted full-field ERG, representing the rod signalling, and alterations in the multifocal ERG reflecting cone and/or postreceptoral function.

Baseline haemoglobin A1c influences retinal function after long-term insulin pump therapy

“…The finding of higher than normal ERG amplitudes during the first year of the study is consistent with other studies of the earliest stages of non-proliferative diabetic retinopathy [24,25]. It also supports the theory that hyperglycemia can lead to a hypermetabolic state in the retina [26].…”

The db/db Mouse: A Useful Model for the Study of Diabetic Retinal Neurodegeneration

“…In this regard, blood-retinal barrier (BRB) breakdown as the result of VEGF upregulation produced by glutamate-induced excitotoxicity has been well documented [9], [11], [12], and a cross-talk between neurodegeneration and vasoregression has been reported [10], [13]. In addition, the impairment of neurovascular coupling which can be detected in diabetic patients without structural abnormalities [32], [33] seems primarily mediated by ganglion cell damage [34]. Finally, it has been shown that a delayed multifocal ERG implicit time predicts the development of early microvascular abnormalities [29], [35]–[37].…”

Validity, Usefulness and Cost of RETeval System for Diabetic Retinopathy Screening

“…Testing took place in a room with no background light, which has been shown to influence detection of STDR. 18 The sensor strips were disposed of to avoid rescreening of other patients using the used strips. The calibration phase followed prior reports with this device.…”