Intact calibers of retinal vessels in patients with systemic sclerosis.

Objective. A primary endothelial cell dysfunction is thought to be involved in systemic sclerosis (SSc)-associated fibroproliferative vasculopathy of the microcirculation and small arterioles, even in sites not affected by fibrosis. Because the role of fibroblasts in pathologic modifications and vascular wall remodeling is relatively unclear, and because the retina provides a unique opportunity to assess microcirculation in the absence of resident fibroblasts, we systematically evaluated retinal vessels in patients with SSc. Methods. Digital retinal images were obtained from both eyes of 93 consecutive patients with fully characterized SSc and 29 healthy controls matched 1:1 for age and sex with selected patients without diabetes, hypertension history, or antihypertensive treatment. Internal microvascular calibers (erythrocyte column width in μm) by central retinal arteriolar and venular equivalents and arteriolar to venular ratio were measured using validated software. Results. Arteriolar and venular calibers were similar in patients and their matched controls (mean ± SEM; 187 ± 2 vs 184 ± 3, p = 0.444, and 211 ± 2 vs 216 ± 3, p = 0.314, respectively). Both arteriolar and venular calibers and their ratio in patients with SSc were not associated with disease duration, extent of skin involvement, pulmonary fibrosis, digital ulcers or pitting scars, amputations, digital capillaroscopic findings, inflammatory indices, or autoantibodies. Conclusion. The evidence that retinal microcirculation is spared in SSc suggests that fibroproliferative vasculopathy may depend on specific cellular or soluble factors not present in the retinal environment.