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 µm, and avascular zones > 200 µm. 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.