Assessment of Clinical Features and Prognosis in Behçet's Disease Patients with Ocular Manifestations: A Focus on Optical Coherence Tomography and Angiography.

Purpose: To compare retinal microvascular structures in ocular (active/inactive) Behçet's disease (OBD) and non-ocular Behçet's disease (NOB) using optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA).

Methods: This cross-sectional study included patients with active/inactive OBD, NOB, and healthy controls. Disease activity was based on clinical findings and fluorescein angiography. OCT and OCTA assessed retinal, choroidal thicknesses, vascular density (VD) and perfusion density (PD), and optic nerve head flow, and foveal avascular zone (FAZ) characteristics. The primary aim was to identify retinal and choroidal microvascular alterations to assess their potential as biomarkers for disease activity and progression.

Results: 16 active OBD, 38 inactive OBD, 20 NOB, and 33 control eyes were analyzed. Most OBD patients were on stable immunosuppressive therapy. Central macular thickness was significantly lower in the inactive OBD eyes (239,9±42.1µm) than in active OBD (275,3±52,3 µm), NOB (263,3±22,6 µm), and controls (267,6±23,6 µm)(P=0.000). Inner retinal layer thicknesses were also reduced (p<0.05). The mean VD and PD were decreased in inactive OBD compared to NOB and controls (p<0.05). Active/inactive OBD patients demonstrated significantly higher FAZ areas and perimeters and significant deterioration in the circularity index at the deep capillary plexus, correlating with visual acuity loss (p<0.05). BCVA was 20/32 (0.63; 0.48 logMAR) in active OBD, 20/36 (0.55; 0.41 logMAR) in inactive OBD, and 20/20 (1.00; 0.00 logMAR) in NOB and controls.

Conclusion: OCT and OCTA identify retinal thinning and vascular loss in OBD, with VD, PD, and FAZ metrics serving as markers of disease activity and visual function.