Evaluation of optic disc and parafovea areas in neurobehçet's patients without ocular involvement using optical coherence tomography angiography

Aim: The study aims to examine vascular changes in the optic disc and macular region using Optical Coherence Tomography Angiography (OCTA) in patients with Neuro-Behçet's disease without ocular involvement. Material and Method: 36 eyes of 19 parenchymal Neurobehçet patients without any ocular pathology were included in the study as the Neurobehçet patient group (NBG). As control groups, 44 eyes of 22 nonocular Mucocutaneous Behçet's disease patients (MBG), and 51 eyes of 26 completely healthy individuals (HG) matched by age and gender were included. Full ophthalmological examination and OCTA measurements were performed in all groups. Results: In the comparison of peripapillary retinal nerve fiber layer (RNFL) thickness, the NBG had the lowest mean, while no significant difference was observed between the groups. In the analysis of peripapillary vascular density (VD), the mean VD in the inferior quadrant was significantly lower in NBG than in the other two groups (p = 0.014). In the foveal region, both the superficial capillary plexus (SCP) and deep capillary plexus (DCP) VD means were significantly lower in NBG compared to MBG (p=0.019 and p=0.02, respectively). Additionally, NBG was observed to have significantly wider foveal avascular zone compared to MBG (p=0.035) In the assessment of choriocapillaris flow rate, the mean values for NBG in both the 1mm and 6mm diameter areas were significantly lower than those in other groups (p=0.002, p=0.000 ,respectively). Conclusion: The ability of OCTA to demonstrate changes in retinal and choroidal blood flow in Neuro-Behçet patients without ophthalmological symptoms or findings suggests the presence of subclinical effects and indicates the potential utility of OCTA in monitoring these patients. Keywords: Behcet, Neuro-Behcet, OCTA, Optic disc, Retina