Purpose: Remnant cholesterol (RC) is a well-recognized risk factor for cardiovascular diseases (CVDs) and an important biomarker of cardiovascular risk. However, studies on the effects of RC on the early retinal microvasculature are still scarce. Therefore, this study aimed to investigate the association between RC and the retinal capillary plexus (RCP) using optical coherence tomography angiography (OCTA). Methods: This cross-sectional study evaluated data from participants of the Jidong Eye Cohort Study. All participants underwent comprehensive ophthalmic examinations and laboratory tests. The RC values were calculated using a recognized formula. OCTA was used to measure vessel density in the RCP. Results: This study included a total of 3903 participants, with a mean age of 43.42 ± 9.88 years; 1946 were female (49.86%). After adjusting for confounding factors, higher RC levels were significantly associated with lower deep RCP vessel density in the parafovea (β = −0.578 per 1-mmol/L increase; 95% confidence interval, −0.875 to −0.282; P < 0.001). Moreover, a significant interaction was observed between sex and RC for deep RCP vessel density in the parafovea (P for interaction = 0.029), with a stronger negative association in male participants. Conclusions: Higher RC levels were significantly associated with lower deep RCP vessel density. Our findings provide evidence supporting the adverse effects of high RC levels on the retinal microvasculature. Translational Relevance: These findings highlight that RC regulation may help prevent microvascular complications, with implications for clinical strategies targeting microvascular health.
Ding et al. (2026) studied this question.