Quantitative Assessment of Swept-Source Optical Coherence Tomography Angiography in VKH Patients Across Different Disease stages

This study aimed to investigate retinal and choroidal changes at different stages of Vogt-Koyanagi-Harada (VKH) syndrome and analyze their association with visual prognosis. This retrospective study comprised 22 healthy controls and 81 VKH patients. Patients were categorized into three groups: the initial-onset, recurrent and quiescent groups. Swept-source optical coherence tomography angiography (SS-OCTA) was used to evaluate the vascular density (VD) and perfusion area (PA) of the superficial, intermediate, and deep retinal capillary plexus (SCP, ICP and DCP), as well as the choroidal vascular index (CVI) and volume (CVV). Best-corrected visual acuity (BCVA) was assessed. Statistical analyses were used to assess the relationship between vascular parameters and visual outcomes. Compared to the control group, patients in the initial-onset stage showed decreased ICP-PA, choriocapillaris perfusion area (CCPA), and CVI (all p < 0.05), while CVV increased (p = 0.01). The PA of retinal capillaries, CVV, and CVI in patients in recurrent or quiescent stage were lower than in the control group (all p < 0.05), and patients in recurrent stage had lower DCP-PA than in the quiescent stage (p = 0.03). The VD of the deep vascular complex, the PA of DCP, and ICP exhibited a negative correlation with BCVA across all VKH groups (all p < 0.05). Binary logistic regression analysis showed that disease course, recurrence, and SCP-PA were positively associated with irreversible complications. The retinal and choroidal vascular systems in VKH show dysfunction throughout various stages, with recurrent inflammation intensifying microcirculatory damage. Monitoring these changes may aid to predict visual prognosis and guide intervention strategies for VKH patients.