The macular ganglion cell-inner plexiform layer (mGCIPL) may serve as a quick and easily obtained measure of generalized neurodegeneration. Investigating factors associated with this thickness could help to understand neurodegenerative processes.
This study aimed to characterize and identify associated factors of the mGCIPL thickness in a Beaver Dam Offspring Study cohort of middle-aged U.S. adults.
Baseline examinations occurred from 2005 to 2008, with follow-up examinations every 5 years. Included participants had baseline data and measured mGCIPL at 10-year follow-up (N = 1848). The mGCIPL was measured using the Cirrus 5000 HD-OCT Macular Cube Scan. Associations between mean mGCIPL thickness and thin mGCIPL, defined as 1 standard deviation (SD) below the population mean, and baseline risk factors were investigated using generalized estimating equations.
Participants (mean [SD] baseline age, 48.9 [9.3] years; 54.4% women) had mean (SD) mGCIPL thicknesses of 78.4 (8.1) μm in the right eye and 78.1 (8.5) μm in the left (correlation coefficient = 0.76). In multivariable models, age (-1.07 μm per 5 years; 95% confidence interval [CI], -1.28 to -0.86 μm), high alcohol consumption (-1.44 μm; 95% CI, -2.72 to -0.16 μm), higher interleukin 6 levels (50% increase in level: -0.23 μm; 95% CI, -0.45 to 0.00 μm), myopia (-2.55 μm; 95% CI, -3.17 to -1.94 μm), and glaucoma (-1.74 μm; 95% CI, -2.77 to -0.70 μm) were associated with thinner mGCIPL. Age (per 5 years: odds ratio [OR], 1.38; 95% CI, 1.24 to 1.53), diabetes (OR, 1.89, 95% CI, 1.09 to 3.27), myopia (OR, 2.11; 95% CI, 1.63 to 2.73), and increasing and long-term high C-reactive protein (ORs, 1.46 [95% CI, 1.01 to 2.11] and 1.74 [95% CI, 1.14 to 2.65], respectively) were associated with increased odds of thin mGCIPL.
Factors associated cross-sectionally with mGCIPL thickness, older age, high alcohol consumption, inflammation, diabetes, myopia, and glaucoma may be important to neural retina structure and health and neuronal health system-wide.

Copyright © 2021 American Academy of Optometry.