Abstract
Purpose :
To investigate choroidal thickness (CHT) in a large population-based study of individuals aged 70+ and to analyze associations of CHT with age-related macular degeneration (AMD).
Methods :
In the population-based AugUR cohort study individuals aged 70 years and older were recruited. AMD status was assessed by grading color fundus images and classified according to the Three Continent AMD Consortium Severity Scale. Enhanced depth imaging optical coherence tomography (EDI-OCT) scans of the macula were generated using the Heidelberg Spectralis OCT device. Subfoveal choroidal thickness (CHT) was measured manually using the caliper tool from the Heidelberg Eye Explorer software. Extremely thick choroids were winsorized. CHT was analyzed by age groups and AMD status. Logistic regression was performed to analyze the association of CHT with AMD status cross-sectionally, adjusted for age, sex, and scan focus (proxy for refraction).
Results :
A total of 1831 participants with available CHT measurement and AMD status for at least one eye were included in the analysis. Median CHT in the 1389 participants without AMD was 236µm. It was similar between men and women (238 vs 231µm) and showed a decrease by age (Figure 1A).
A total of 345 individuals had early and 97 had late AMD. CHT decreased by AMD severity and was thinnest in individuals with geographic atrophy (GA) (Figure 1B). Logistic regression adjusted for age, sex, and scan focus revealed a significant association of CHT with GA: odds ratio (OR) per µm CHT for no AMD vs GA=0.992, 95%-confidence interval (CI)=[0.986, 0.997], P-value=0.002. CHT difference between no AMD and combined GA plus macular neovascularization (MNV) was also significant (OR=0.992, 95%-CI=[0.985, 0.999], P=0.022). There was no statistically significant association between CHT and MNV only (P=0.81) or early AMD stages (P=0.94) in comparison to no AMD.
Conclusions :
Our study aids in establishing normative values for CHT in an elderly population, where data on CHT have been scarce. We also demonstrate a decrease of CHT by age. When focusing on AMD status, CHT is significantly thinner in the presence of GA compared to no AMD.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.