Normative Distribution of Optical Coherence Tomography Retinal Features and Associations with Visual Function in Older Adults (from the Eye Determinants of Cognition Study)

Abstract

Purpose : Structural and angiography measures of retinal optical coherence tomography (OCT) imaging are often employed clinically to evaluate retinal health in individual patients. However, the normative distribution of these measures across older populations has not been well characterized. Here we describe the distribution of retinal features and its associations with visual function in a population-based bi-community sample from the Eye Determinants of Cognition (EyeDOC) study.

Methods : OCT structural and angiographic images were obtained in EyeDOC participants from two communities: Jackson, MS (all Black) and Washington County, MD (all White). Retinal measurements included retinal nerve fiber layer (RNFL) thickness, macular ganglion cell complex (GCC) thickness, macular vessel density (VD, % of area covered by vessels) in the superficial and deep capillary plexus (SCP and DCP), and the area of the foveal avascular zone (FAZ). Aspects of visual function including corrected distance visual acuity (VA) and contrast sensitivity (CS) were assessed. Differences in means for each retinal feature by age and community were tested using t-test and one-way ANOVA. Associations of visual function with retinal features were estimated from adjusted linear regression models.

Results : Retinal measures were available in 759 participants (46% black; 63% female; mean age 80 years[range: 73-94 years]). Mean GCC thickness was lower for Jackson vs. Washington County participants (89.2 μm, 92.3 μm, p<0.001). Mean VD in DCP were statistically lower for participants ≤ 80 years old (44.67%, 43.69%, p<0.001). Mean FAZ differed by community (Jackson: 0.36 mm², Washington: 0.26 mm², p<0.001; Table 1). Each 10 μm increase in RNFL thickness was related to 0.016 logCS better (95% confidence interval[CI]: 0.005-0.027, p=0.004) among all participants and 0.012 logMAR VA better (95% CI: 0.001-0.023, p=0.049) among Jackson participants (Table 2). Each 10 μm increase in GCC thickness was associated with 0.016 logCS better (95% CI: 0.003-0.029, p=0.017) overall, with a larger effect among Jackson participants (ß=0.022, 95% CI: 0.006-0.040, p=0.009).

Conclusions : Results from this aging bi-community population suggested that different references should be used for different age and community groups for structural and functional retinal evaluations.

This is a 2021 ARVO Annual Meeting abstract.