Abstract
Purpose :
To evaluate three measures of inner-retina function, the pattern electroretinogram (pERG), the photopic negative response (PhNR), and the post-illumination pupil response (PIPR), in diabetics who have different stages of non-proliferative diabetic retinopathy (NPDR).
Methods :
Fifteen non-diabetic control subjects and 45 type 2 diabetic subjects (15 have no clinically-apparent retinopathy [NDR], 15 have mild NPDR, and 15 have moderate/severe NPDR) participated. The pERG was elicited by a contrast reversing checkerboard pattern and the PhNR was elicited by a full-field, long-wavelength (642 nm), flash presented against a short-wavelength adapting field (465 nm). The PIPR was elicited by a 1-sec, full-field, 450 cd/m2, short-wavelength flash (465 nm) after dark adaptation. All responses were recorded and analyzed using conventional techniques. One-way analysis of variance (ANOVA) with Holm-Sidak multiple comparisons were performed to compare the pERG, PhNR, and PIPR among the control and patient groups.
Results :
ANOVA indicated statistically significant differences among the subject groups for all three measures (all F > 4.73, p < 0.01). Follow-up comparisons indicated small, non-significant reductions in the pERG (8%), PhNR (8%), and PIPR (10%) for the NDR group compared to the controls. In contrast, there were significant reductions in the pERG (31%), PhNR (30%), and PIPR (28%) for the mild NPDR group compared to the controls. Likewise, there were significant reductions in the pERG (40%), PhNR (32%), and PIPR (32%) for the moderate/severe NPDR group compared to the controls.
Conclusions :
Abnormalities of the pERG, PhNR, and PIPR provide evidence for inner-retina neural dysfunction in diabetics who have clinically-apparent vascular abnormalities. Taken together, these measures provide a non-invasive, objective approach to study neural dysfunction of the inner-retina in these individuals.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.