POS1170 EXPLORING SUBCLINICAL MICROVASCULAR CHANGES IN ANCA-VASCULITIDES: THE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AND NAILFOLD CAPILLAROSCOPY IN THE EVALUATION OF DISEASE-RELATED DAMAGE

Background Both cardiovascular and complement-mediated disorders might lead to microvascular damage in anti-neutrophil cytoplasm autoantibodies (ANCA)-associated vasculitides (AAV). No evidence of subclinical microvascular retinal abnormalities neither their potential correlation with capillaroscopy anomalies has been reported in eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), and microscopic polyangiitis (MPA). Objectives We aimed at investigating subclinical microvascular abnormalities by analyzing retinal and nailfold capillary changes in an AAV cohort. Retinal plexi were investigated using optical coherence tomography angiography (OCT-A), while nailfold capillary changes with videocapillaroscopy (NVC). Potential correlations between OCT-A abnormalities and both disease damage and periungual capillaries change were also explored. Methods A monocentric observational study was conducted on consecutive AAV. Main inclusion criteria were a defined diagnosis of EGPA/GPA/MPA in accordance with International Criteria, age ≥18 ≤ 75 yrs, intraocular pressure (IOP) <21 mmHg by Goldmann, a best-corrected-visual-acuity (BCVA) ≥ 0,5 logMAR, and no ophthalmological and/or systemic disorders or treatment with known retinal involvement. Disease activity was assessed by Birmingham Vasculitis Activity Score (BVAS), damage by Vasculitis Damage Index (VDI), and poorer prognosis by the Five Factor Score (FFS). Moreover, OSDI and MIDAS questionnaires have been administered. Quantitative analysis of vessel density (VD) was performed by OCT-A in the superficial capillary plexi (SCP) and deep capillary plexi (DCP) for all subjects. For completeness, a structural analysis of retinal thickness was performed by OCT-scans. Figures and detailed analysis from NVC were performed for all AAV patients. Results From 47 consecutive AAV patients referring to the Rheumatologic Clinic, 23 consecutive patients who met the inclusion criteria were included and compared with 20 age/sex-matched healthy subjects (HC) (Table 1). In AAV, BVAS correlated directly with VDI (P=0.001) and FFS (P=0.01) while it was inversely related with disease duration (P=0.01). A total of 46 eyes from AAV patients were analyzed. Retinal VD in superficial whole (SWD) and parafoveal (SPFD) plexi were significantly decreased in AAV compared to HC (P=0.02 and P=0.01, respectively, Figure 1A-B). Furthermore, deep whole (DWD) and parafoveal vessel density (DPFD) were strongly reduced in AAV than HC (P ≤0.0001 for both, Figure 1C-D). In AAV patients, significant inverse correlations emerged between VDI and OCTA-VD in both the superficial (parafoveal, P=0.03) and the deep plexi (whole, P=0.003, and parafoveal P=0.02). The retinal thickness measured by OCT-scans was similar between AAV patients and HC. At NVC examination we found non-specific pattern abnormalities in 82% of AAV patients. Common abnormalities were pericapillary edema (73%), tortuosity (65%), while rare cases of ectasias and hemorrhages resulted (0.8%). No meandering capillaries nor empty dermal papillae were observed. Correlations between NVC changes and OCT-A abnormalities were not described. Conclusion Subclinical microvascular retinal changes occur in patients with AAV and correlate with the disease-related damage. In this context, the OCT-A can represent a useful tool in the early detection of vascular damage. AAV patients present microvascular abnormalities at NVC, whose clinical relevance requires further studies. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests None Declared.