Abstract:AIM: To investigate the association between anti-DFS70 antibody positivity and ocular parameters, specifically, the choroidal vascularity index (CVI) and other optical coherence tomography (OCT) metrics, in a healthy population. METHODS: This age- and sex-matched case-control study enrolled 84 healthy individuals with positive anti-DFS70 antibody findings and 84 healthy negative controls. All participants underwent detailed ophthalmological examinations, including biometry and OCT imaging. Anti-DFS70 positivity was determined by indirect immunofluorescence and scored semi-quantitatively (1+ to 3+). CVI was calculated from OCT images using a standardized protocol with Image J software. Statistical analyses, including Student’s t-test, Mann-Whitney U test, Spearman correlation, and logistic regression, were used to compare groups and identify predictive factors. RESULTS: The individuals who tested positive and negative for anti-DFS70 included in the study were matched for age (median age=47y) and sex (F:M=7:1). CVI was significantly lower in the anti-DFS70-positive group compared to the negative group. A higher anti-DFS70 antibody titer was significantly associated with decreased subfoveal and nasal choroidal thickness (P=0.016 and P=0.014, respectively). In univariate regression analysis, CVI was the only significant predictor of anti-DFS70 positivity [odds ratio (OR)=0.02, P=0.025]. Multivariate analysis revealed a positive correlation between macular thinning outside the subfoveal area and anti-DFS70 status (P<0.05). CONCLUSION: Our study demonstrates a novel association between anti-DFS70 antibody positivity and reduced choroidal vascularity in healthy individuals. These findings suggest that anti-DFS70 antibodies may be associated with subtle choroidal vascular changes detectable by OCT, even in asymptomatic individuals. Further longitudinal research is warranted to clarify the underlying mechanisms and long-term clinical significance of these ocular changes.