Thickness of ten retinal layers from macular optical coherence tomography (OCT) volume scans in participants with and without diabetes and their relationship with glucose metabolism

Abstract

Purpose : We investigate the relationship between macular retinal thickness and glucose tolerance in a large population-based study.

Methods : All participants with available measurements (C-peptide, fasting plasma glucose, HbA1c, and OCT scans) from the LIFE-Adult study, a population-based, sex- and age-stratified study, were included. Macular volume scans (97 B-scans by 512 A-scans) from Spectralis OCT were automatically segmented into ten layers after excluding low-quality (< 20 dB) B-scans. The Early Treatment Diabetic Retinopathy Study (ETDRS) grid was used to calculate average sectorial thickness, adjusted by scan length and location of the fovea center. Figure 1 shows the abbreviations of layers and sectors. ANOVA, t-test (significance level: p<0.05), and linear regression (Akaike Information Criterion [AIC] difference >6 defining a strong effect) were used to identify and compare impacts on retinal thickness.

Results : Figure 1A shows the average of ETDRS sectorial thickness in ten layers of the selected 13138 eyes (7234 participants), grouped as diabetic, prediabetic, and normal glucose tolerant. As we did not find significant lateral differences, only right-eye results are presented (6597 eyes/participants). Figure 1B-C reveals extensive retinal thinning in the diabetic group compared with the subjects with normal glucose tolerance, especially in inner layers, with stronger effects for males compared to females. Increasing age was significantly associated with retinal thinning in nearly all layers except RNFL, OPL, and IZ, where age had no or opposite effects (Figure 2A). Apart from age, diabetes-related parameters (e.g., C-peptide) exhibited additional effects on retinal thinning (Figure 2B-C). In males, strong effects of C-peptide were observed in the inner sectors of RNFL, GCL, IPL, outer sectors of ONL, and MZ, while in females, effects were more pronounced in the outer sectors of ONL, MZ, and some sectors in EZ+OS.

Conclusions : In this large population-based sample, participants with diabetes showed extensive retinal thinning compared to normal glucose tolerant subjects. Age had strong effects on retinal thinning. In addition, diabetes-related parameters were linked to thickness of specific layers, with different patterns in males and females.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Figure 1

 

Figure 2