Abstract
Purpose :
The identification of functional and/or structural biomarkers to indicate the degree of retinal ischemia and neurodegeneration is essential for predicting diabetic retinopathy (DR) progression prior to physical manifestations in the eye. Analysis of retinal layer thickness by optical coherence tomography (OCT) and functional evaluation by multifocal electroretinography (mfERG) are two diagnostic tests that reflect neurodegeneration status. We predict that type 2 diabetic patients with abnormal mfERG and retinal layer thickness values are at higher risk for developing or progressing DR. The present analysis was carried out to test this hypothesis.
Methods :
The present study included the dataset we reported previously (Chan et al., ARVO 2019) along with additional subjects recruited from our eye clinic. Subjects were classified as normal (no diabetes, n=13), or as diabetics with (n=15) or without (n=27) retinopathy. The retinal thickness was obtained with OCT at the 9 cardinal points defined by the ETDRS: in the fovea and at 4 points each in two concentric rings in the para- and perifovea, respectively. These thickness measurements were correlated to the amplitude and latency of the N and P components in the mfERG recorded with a Diagnosys system from corresponding retinal locations, i.e. Ring 1, Ring 3, and Ring 5. One-way ANOVA and Pearson’s correlation were used for statistical analyses of the data.
Results :
Although simple comparisons of retinal thickness measurements with mfERG among the three subject groups were often not significant, Pearson’s correlation of retinal thickness with various mfERG parameters returned several significant findings. Examples include OCT ring 1 (fovea) with mfERG ring 1, N1 latency (r=0.627, p=0.029); OCT ring 1 with mfERG ring 1 P1 amplitude (r=0.720, p=0.006), OCT ring 2 with mfERG ring 5 P1 amplitude (r=0.605, p=0.036); and OCT ring 2 with mfERG ring 5 P1 amplitude (r=0.8001, p=0.002). In general, thickening of the retina was associated with an increase in mfERG latency and a decrease in amplitude.
Conclusions :
Our results show strong correlations between mfERG parameters and retinal thickness, suggesting that these are biomarkers related to the status of advanced DR and possibly from poor treatment outcome. Moreover, these findings support the development of an algorithm to combine these diagnostic biomarkers as a prognostic indicator of DR in type 2 diabetic patients.
This is a 2020 ARVO Annual Meeting abstract.