The frequency of early age-related macular degeneration and its relationship with dietary pattern in Hunan, China: a cross-sectional study.

Purpose: To estimate the frequency of age-related macular degeneration (AMD) among people who underwent health examination in Hunan, China and to determine the relationship between dietary pattern and the risk of AMD.

Methods: The Questionnaire was used to collect dietary data from 56,775 study participants of ≥ 50 years old who underwent health examination at the Department of Health Management, the Third Xiangya Hospital of Central South University between January 2017 and December 2019. The diagnosis of AMD was based on the results of color fundus photography (CFP), spectral-domain optical coherence tomography (OCT) and multispectral imaging (MSI). After excluding participants with incomplete records or other ocular disease that may affect the results of fundus examination, a total of 43,672 study participants were included. The univariate and multivariate logistic regression analyses were used to determine the relationship between dietary pattern and the frequency of AMD.

Results: Among the 43,672 study participants, 1080 (2.5%) had early AMD: the frequencies were 2.6% (n = 674) in men and 2.3% (n = 406) in women; the frequencies were 1.0% (n = 289), 3.6% (n = 401), 9.1% (n = 390) in 50-59, 60-69, ≥ 70 years old, respectively. And the age-standard frequency was 6.6% over the 60 years old in Hunan China. The high-salt intake increased the risk of early AMD [odds ratio (OR) = 1.61, 95% confidence interval (CI) = 1.54-1.68], whereas the intake of meat decreased the risk (OR = 0.90, 95% CI = 0.81-0.99).

Conclusion: In Hunan China, there was a high frequency of early AMD detected through health examination over the 60 years old. And high-salt intake increases the risk of early AMD, whereas intake of meat decreases the risk. Modulating the dietary pattern and reducing the salt intake as an AMD prevention strategy warrant further study.