Electroretinography and retinal microvascular changes in type 2 diabetes

Abstract

To assess whether functional (electrophysiological) parameters are related to changes in the structural (microvascular) parameters in diabetic retina. Methods: This prospective cohort study included 380 eyes of patients with diabetes mellitus (DM) and 160 eyes of healthy controls. We analysed the electroretinogram (ERG) parameters and vascular parameters acquired from optical coherence tomography (OCT) angiography according to the diabetic retinopathy (DR) severity from early to late stages of DR. Results: After exclusion, 366 eyes of diabetes and 157 eyes of controls were included in the analysis. The mean age at enrolment was 65.4 AE 7.8 years, and 177 (33.84%) were male. The amplitude and implicit time of the rod and cone and combined response ERG b-wave were significantly reduced and prolonged in the eyes of patients with DM, compared to the controls. There was a positive correlation between the amplitude and vessel density (VD) of the superficial plexus and a negative correlation between the implicit time and superficial VD in the scotopic and combined response b-wave. Interestingly, there was no correlation between electrophysiological parameters and deep VD. These correlations between electrophysiological parameters and vascular parameters were not significant in the non-diabetic, healthy control group. Conclusions: Functional and structural impairments precede the clinical manifestation of DR. We also found that these neural impairments, evaluated by ERG, were correlated with superficial VD. However, this correlation was absent in the healthy and early DR groups. These findings carefully suggest that neuronal dysfunction is linked to vascular dysfunction in type 2 diabetes.

Early Retinal Changes by OCT Angiography and Multifocal Electroretinography in Diabetes

“…Moreover, we specifically found a significant macular functional alteration by mfERG in noDR, showing an early functional impairment more evident in patients without clinical signs of DR but with a rarefaction of SVP. A correlation between ERG parameters and the superficial vascular density has already been suggested by Kim et al [39]. However, in that study the use of full field ERG, instead of mfERG, evaluated the electrical activity generated throughout the whole retina, whereas we studied the mfERG response, localized at the posterior pole, corresponding to the area of analysis of OCTA [39].…”

Assessment of optical coherence tomography angiography and multifocal electroretinography in eyes with and without nonproliferative diabetic retinopathy

“…[ 13 ] A recent study by Kim et al . [ 14 ] examined the correlation between OCT macular vessel density and full-field ERG. A positive correlation was observed between the ERG amplitude and vessel density, and a negative correlation between the implicit times and superficial vessel density in the scotopic and combined response b-wave.…”

“…The study by Kim et al . [ 14 ] utilized a full-field ERG that evaluates the mass electrical activity from the entire retina. Our study utilized a multifocal ERG that allows recording and analysis of multiple focal retinal responses.…”

MicroRNA-150 (miR-150) and Diabetic Retinopathy: Is miR-150 Only a Biomarker or Does It Contribute to Disease Progression?

“…In a mouse model of T2D (KKAY), the terminal UTP nick-end label (TUNEL) staining shows an increased number of apoptotic neurons in the GCL [ 34 ], and neuronal apoptosis in the retina occurs in T2D (db/db) mice starting from twenty weeks old [ 35 ]. These findings reveal the degeneration of the inner retina in diabetes, which may explain the dampened light response reflected by the decreased amplitude and increased implicit time of ERG b-waves [ 36 , 37 ].…”