Comparison of multimodal imaging findings in Behçet's Disease

Objective: Behçet's Disease (BD) is a multisystemic chronic disease characterized by chronic occlusive vasculitis with attacks and remissions. The etiology of BD, which primarily affects oral and genital mucosa, skin and eye, is not exactly known. Ocular inflammation occurs in approximately 70% of patients with BD. Panuveitis and retinal vasculitis are seen in the majority of them. Fundus Fluorescein Angiography (FFA) is the gold standard diagnostic test in the diagnosis of vasculitis. Optical Coherence Tomography (OCT), Optical Coherence Tomography Angiography (OCTA) are other imaging methods used in the diagnosis and follow-up of Behçet's uveitis, showing macular anatomy, retinal layers and microvascular changes. It was aimed to compare imaging findings in the presence or absence of uveitis in BD and to evaluate their reliability in diagnosis and follow-up. Methods: Patients followed for uveitis 2˚ to BD in NEU between Feb 2021 & Feb 2022, patients with BD without uveitis ans patients who applied routine eye exem were included. Central macular thickness (CMT) with OCT, subfoveal choroidal thickness (SFCT) with EDI-OCT, foveal avascular zone area (FAZ), total deep capillary plexus density, total superficial capillary plexus density, deep parafoveal capillary plexus density, superficial parafoveal capillary plexus density and peripapillary capillary plexus density values with OKTA were obtained. In addition, FFA imaging of patients with Behçet's uveitis was evaluated. According to the distinction made on the basis of the vascular arcades, the superior, inferior, temporal, nasal areas, optic disc and macular involvement were scored. Involvement in each region was evaluated +1 point. These values were compared statistically between groups. Correlation of these values with visual acuity and disease duration was assessed. Results: A total of 236 eyes of 79 patients and 39 control groups were included in the study. The patients were between the ages of 18-63, with a mean age of 37.35 year in the group with ocular involvement, 36.21 year in the group without ocular involvement, and 33.79 year in the control group. Of the patients 48.6% were female, 51.4% were male; in group with ocular involvement 35.7% were female and 64.3% were male in the group without ocular involvement; 51.3% of the control group were female and 48.7% male. The mean disease v duration was 6.49 years in the group with ocular involvement and 6.71 years in the group without ocular involvement. A statistically significant difference was found in the mean FAZ area, total superficial capillary plexus density, total deep capillary plexus density, deep perifoveal capillary plexus density, superficial perifoveal capillary plexus density and peripapillary capillary plexus density of the groups. Capillary plexus densities were lower in the group with ocular involvement compared to the other groups; FAZ area was found higher than the other groups. In the group with ocular involvement, it was observed that parameters other than FAZ area were positively related and area was negatively related with the evaluation of FFA. Conclusion: Optical coherence tomography angiography (OCTA) is an important noninvasive imaging modality in detecting macular microvascular changes associated with final visual acuity as a result of recurrent episodes of Behçet's uveitis. OCTA can also provide information about the decreased deep and superficial capillary reserve due to vasculitis in Behçet's patient without ocular involvement. Key words: Behçet's Disease, Uveitis, Optical coherence tomography, Fundus fluorescein angiography, Retina, Choroid