Supplementary Material for: Choroidal Osteoma with Focal Choroidal Excavation Masquerading as Active VKH: A Case Report

Purpose
This case report highlights the diagnostic challenges of identifying choroidal osteoma in a patient with a history of Vogt-Koyanagi-Harada (VKH) disease. Given the overlapping clinical features of inflammatory and non-inflammatory choroidal lesions, we underscore the importance of comprehensive multimodal imaging to avoid misdiagnosis and ensure appropriate management.
Methods
A rare case of choroidal osteoma in a patient with 14-year history of VKH was documented using multimodal imaging, including wide-field fundus photography, optical coherence tomography, fundus autofluorescence, OCT angiography, fluorescein angiography, and B-scan ultrasonography.
Results
We describe a 39-year-old female with a 14-year history of VKH disease, who had been stable off immunosuppressive therapy since 2016. In early 2024, she presented with a 7-week history of cloudy vision in the right eye. Initially diagnosed with a recurrent posterior VKH relapse, she received high-dose intravenous corticosteroids followed by an oral taper. Although her symptoms improved, further evaluation revealed a yellow-orange, minimally elevated subretinal lesion consistent with choroidal osteoma, associated with focal choroidal excavation, that was confirmed by EDI-OCT and B-scan ultrasonography.
Conclusion
This case illustrates a rare instance of choroidal osteoma mimicking a posterior relapse of VKH. It highlights the critical importance of distinguishing between inflammatory and non-inflammatory choroidal lesions in patients with a history of uveitis. Accurate diagnosis through thorough multimodal imaging can prevent unnecessary treatment and its associated risks, ultimately leading to better patient outcomes.