A Cross-Sectional Observational Study of Nailfold Capillary Morphology in Uveitis

Purpose: We performed nailfold capillary microscopy to explore microvasculature abnormalities in uveitis overall and uveitis stratified in various ways.Methods: This was a cross-sectional, case-control, observational study. One hundred and seven uveitis patients and 130 control subjects were included. We used a JH-1004 capillaroscope to perform nailfold capillary video microscopy on the fourth and fifth digits of each subject's nondominant hand. Videos were evaluated for hemorrhages, dilated capillary loops >25 mu m, and avascular zones >200 mu m. Univariate analyses were used for the assessment of case-control morphological differences and multivariate analyses were performed to assess the relation between nailfold capillaroscopic findings and uveitis subgroups.Results: In univariate analysis, uveitis patients were more likely to have higher tortuosity ratings and reduced capillary density compared to controls (p<0.001 for both); furthermore, dilated capillary loops, avascular zone and hemorrhages were more frequent in uveitis versus control subjects (p<0.001 for all). Among cases, every unit increase in capillary density (vessels/mm) was associated with active uveitis (n=72 cases) versus inactive disease (n=35 cases; odds ratio (OR)=1.7; (95% confidence interval (CI), 1.2-2.5) in multivariate analysis. Furthermore, the presence of any nailfold hemorrhage versus the absence of hemorrhage was more likely to be associated with posterior and panuveitis (n=41 cases combined) compared to anterior and intermediate uveitis (n=66 cases combined; OR=5.8; 95% CI, 2.3-14.2). Moreover, we found a positive correlation between peripheral retinal leakage and nailfold capillaries dilation (r=0.33; p=0.015) that was not strictly significant based on the number of comparisons made.Conclusions: Our study provides support for non-ocular capillary bed abnormalities in uveitis, with interesting correlations based on disease stage and anatomical classification.