Vascular Changes and Irreversible Complications in 120° Fundus Using Widefield SS-OCTA in Vogt-Koyanagi-Harada Disease

Purpose: To characterize the changes of fundus corresponding to 120° field of view in chronic Vogt-Koyanagi-Harada (VKH) disease in the quiescent phase, and explore the associations with irreversible complications in the fundus utilizing widefield swept source optical coherence tomography angiography (SS-OCTA). Methods: Prospective cross-sectional study. Sixty-nine chronic VKH patients (115 eyes) and 55 healthy controls (110 eyes) were included and underwent widefield SS-OCTA. Univariate analyses of variations in retinal and choroidal vessel density (VD), choroidal volume, and choroidal vascularity index (CVI) in VKH patients with different disease durations and the controls were conducted. Logistic regression analysis was employed to identify the associations with irreversible complications including choroidal neovascularization, vasoproliferative tumour of the retina, and chorioretinal atrophy. Results: The Welch’s analysis of variance showed lower VD of superficial retina, deep retina, choriocapillaris, and large-sized and medium-sized vessels of the choroid (LMVC), and choroidal volume and CVI in the patients with disease duration > 24 months compared to those with disease duration ≤ 24 months (all P≤0.011). The regression analysis revealed the disease duration (P=0.008; OR=1.02, 95%CI=1.005-1.035) and VD of LMVC (P=0.001; OR=0.707, 95%CI=0.575-0.87) were significantly correlated with the irreversible complications. Conclusions: Chronic VKH patients in the quiescent phase with disease duration > 24 months exhibit more severe decreased VD in each layer of the retina and choroid, reduced choroidal volume and sparse choroidal vascularity compared to those with disease duration ≤ 24 months. Prolonged duration and decreased VD of LMVC were associated with irreversible complications in the fundus.