Microvascular markers in systemic sclerosis: a comparative OCT-angiography and nailfold videocapillaroscopy study.

PURPOSE: To investigate the effect of disease duration on retinal microvasculature in patients with systemic sclerosis (SSc), and to explore its correlation with nailfold videocapillaroscopy (NFC) findings and systemic organ involvement. METHODS: Patients were divided into subgroups according to disease duration (≤5 years, >5 years, <10 years, ≥10 years). Retinal microvasculature was evaluated by OCT-A in the superficial (SCP) and deep (DCP) plexuses, and peripheral microcirculation was assessed by NFC. Correlations between retinal microvascular parameters, disease duration, systemic involvement, and nailfold capillary density were analyzed. RESULTS: This cross-sectional study included 37 SSc patients without retinopathy and 37 healthy controls. The mean duration of disease was 10.5±7.4 (1-30, median: 10.5 years). Central foveal thickness was significantly higher in the SSc group than in controls (p < 0.001). The VD values of SSc patients in both plexuses were significantly lower compared to the healthy control group (p < 0.05, for all). In subgroup analyses, SCP VD was significantly higher in the whole, parafoveal, and perifoveal areas in the SSc-<10y group compared with the SSc-≥10y group (p=0.03, p=0.025, p=0.005). NFC data revealed that the mean capillary number was significantly higher in SSc-<10 y compared to SSc≥10 y (p=0.043). Capillary density was positively correlated with SCP VD (whole; r = 0.606, p < 0.001, parafovea; r=0.487 p=0.002, perifovea, r=0.603 p<0.001). CONCLUSION: The study findings indicate that SCP-VD may serve as a surrogate quantitative marker of systemic vascular involvement during the progressive course of SSc. OCT-A holds promise as a robust, non-invasive modality for disease monitoring and prognosis.