The Impact of Inflammatory Markers on the Ganglion Cell Complex in Non-Glaucoma Subjects

Abstract

Purpose : Prior studies suggest that inflammation is associated with glaucoma, and glaucoma is known to damage the ganglion cell complex (GCC), defined as the three innermost retinal layers, including the nerve fiber layer, the ganglion cell layer, and the inner plexiform layer. Here, we study the impact of inflammation on GCC thickness in non-glaucoma subjects.

Methods : From the large population-based LIFE-Adult study (Leipzig Research Centre for Civilization Diseases), we extracted the machine-segmented GCC thickness map from Heidelberg Spectralis macular optical coherence tomography (OCT) scans. Subjects with glaucomatous findings on fundus photos, self-reported glaucoma, or glaucoma medication intake were excluded from data analyses. Inflammatory status was assessed by high-sensitivity C-reactive protein (hsCRP) and interleukin 6 (IL-6). The two inflammatory markers were separately associated with the global, sectoral and pointwise GCC thickness by partial correlations adjusted for age, sex, and scan focus. P values were corrected for multiple comparisons. One eye per subject was selected randomly if both eyes were available.

Results : 7,521 eyes from 7,521 subjects (age: 56.7 ± 12.5 years; 52.0% female) were included. Higher IL-6 (partial correlation [r]: -0.02, p = 0.01) but not hs-CRP (p = 0.79) was significantly associated with thinner global average GCC. Figure 1 shows the pointwise partial correlations between inflammatory markers and GCC thickness. Higher hs-CRP and IL-6 were particularly associated with thinner GCC thickness in the parafoveal ring-shaped region significantly affecting 20.9% and 20.4% of the scan region, respectively. Figure 2 shows the sectoral partial correlations between the inflammatory markers and GCC thickness using Early Treatment Diabetic Retinopathy Study based sectors. Both hsCRP (each p ≤ 0.049) and IL-6 (each p ≤ 0.001) were significantly associated with thinner GCC in the four inner sectors. In addition, hsCRP had significant associations (p = 0.049) with thicker GCC in the superior outer sector, and IL-6 had significant associations (p = 0.02) with thinner GCC in the nasal outer sector.

Conclusions : Our results suggest that higher levels of inflammatory markers are specifically linked with thinner GCC in the parafoveal ring-shaped region in non-glaucoma subjects, which may help better understand the inflammatory pathway in the pathogenesis of glaucoma.

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

 

Figure 1

 

Figure 2