Longitudinal corneal thickness changes and their relation to ocular and systemic cardiovascular risk factors: Results from the Gutenberg Health Study

PURPOSE: This study aimed to evaluate 5-year longitudinal changes in both central and peripheral corneal thickness and to explore associations with ocular characteristics as well as systemic cardiovascular risk factors (CVRF). METHODS: The Gutenberg Health Study is a prospective population-based cohort study comprising 15 010 participants aged 35-74 years at baseline. Scheimpflug tomography (Pentacam, Oculus, Wetzlar, Germany) was performed during both the 5-year (2012-2017) and 10-year (2017-2022) follow-up examinations. Longitudinal changes in central corneal thickness (CCT) and in concentric rings at 2 mm (D2), 4 mm (D4), 6 mm (D6), 8 mm (D8) and 10 mm (D10) were evaluated in eyes with available measurements at both time points. Additionally, associations between changes in CCT and ocular characteristics as well as systemic CVRFs at the 5-year FU as well as its 5-year changes (Δ) were investigated by multivariable linear regression analyses using generalized estimating equations. RESULTS: 8755 eyes of 4857 participants were included and a significant reduction in CCT was observed across all age groups over 5 years. Peripheral corneal thickness remained stable over time. Multivariable analyses identified associations with a change in CCT and ocular characteristics including corneal diameter (B = -0.06, p < 0.0001), axial length (B = 0.04, p < 0.008), pseudophakia at the 5-year examination (B = -0.18, p < 0.03) as well as systemic CVRF including age (B = -0.04, p < 0.008), HbA1c (B = 0.03; p < 0.040), ΔHbA1c (B = 0.05; p < 0.001), ΔLDL (B = -0.03, p < 0.047), ΔHDL (B = -0.05, p = 0.0006), ΔMAP (B = -0.04, p < 0.01) and a continuous smoking status (B = 0.08, p < 0.035). CONCLUSION: While observing a 5-year decline in CCT, peripheral corneal thickness remained relatively stable. We observed longitudinal associations between CCT changes and HbA1c, lipid profile, mean arterial pressure and smoking, suggesting that corneal thickness changes may be influenced by cardiovascular and metabolic health and thus may be taken into consideration in glaucoma risk stratification.