Relation between Nail Fold Capillaroscopy, Optical Coherence Tomography Angiography, and Femoral Vein Wall Thickness in Behçet's Disease

Behçet disease (BD) is a multisystemic, autoinflammatory, chronic illness that is quite common in the nations along the ancient Silk Road. It is characterized by immune-mediated vasculitis, which can affect blood vessels of any size throughout all organ systems Vascular involvement, is one of the more serious symptoms of BD, which is considered to have a poor prognostic value. The majority of research on vascular involvement in BD focuses on large vessel involvement; however, less research discusses microvascular damage. Capillaroscopy is a non-invasive diagnostic method used to assess small vessels in the microcirculation Furthermore, ocular inflammation is the most prevalent form affecting more than 70% of Behçet diseased patients in the form of relapsing, remitting uveitis Fluorescein angiography is currently the gold standard for documenting and tracking posterior segment involvement in BD because it can easily detects retinal ischemia, macular edema, and retinal vascular leakage . Nevertheless, this process is invasive, necessitating the injection of an external dye, and its depth resolution is restricted Recently, optical coherence tomography angiography (OCT-A) has emerged as a highly effective method for obtaining high resolution en face images of the choroidal and retinal microvasculature, as well as for analyzing changes in the choriocapillaris, deep capillary plexus, and superficial capillary plexus independently . OCT-A allows for the assessment of both qualitative and quantitative alterations within the retinal microvasculature. Few research have looked into the use of OCT-A in Behçet uveitis, despite the fact that its role in the evaluation of retinal vascular diseases, such as diabetic retinopathy, retinal venous occlusions, retinal arterial occlusions, and age-related macular degeneration, has been thoroughly examined in the recent literature It has recently been proposed that venous wall thickness (VWT), measured by Doppler ultrasonography (US), can serve as an indirect sonographic marker for the extent of vascular end organ damage, including venous illness. Increased VWT, particularly in the femoral and popliteal veins, has been shown in numerous investigations to be a highly significant clinical characteristic in BD However, whether US findings are correlated with vascular involvement in BD is still unknown. It has been determined that the most suitable site to evaluate VWT using US is the common femoral vein (CFV). A sensitivity of 81-22% and a specificity of 78.4-81.1.1% have been reported for the VWT cut-off point of ≥0.5 mm in the diagnosis of BD. It has therefore been suggested as an efficient and non-invasive method for diagnosing BD

Inclusion Criteria:

1. Adult BD patients who fulfilling the criteria for the diagnosis by International Team for the Revision of the International Criteria for Bechet's Disease .
2. Accept to participate in the current study -

Exclusion Criteria:

1. Individuals with other autoimmune diseases (rheumatoid arthritis dermatomyositis, scleroderma, mixed connective tissue disease).

2. Patients with high myopia or media opacities preventing high-quality imaging like cataract and cornea guttata, vitreoretinal disease, previous retinal surgery, macular edema, glaucoma or neurological disease.

3. Patients with other comorbidities as diabetes, hypertension were excluded from the study.

4. Refused to participate in the current study.

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The study will include 80 participants:

Group 1: 40 patients with who fulfilling the criteria for the diagnosis by International Team for the Revision of the International Criteria for Bechet's Disease (Disease et al., 2014).

. Group 2: 40 healthy matched controls.