STAGE-WISE CHARACTERIZATION OF CHOROIDITIS USING THE BLEND FUNCTION IN ULTRA-WIDEFIELD IMAGING.

Abstract

To characterize the imaging features of choroiditis across different disease stages using the blend function in ultra-widefield imaging (UWFI) and compare its findings with fundus autofluorescence (FAF). This study included 30 patients (25 eyes) with choroiditis, categorized into active, resolving, and healed stages. UWFI images were analyzed using the red and green channels to assess specific imaging characteristics at each disease stage. FAF findings were compared to evaluate disease activity and progression. Active choroiditis lesions were distinctly visualized on the green channel with well-defined inflammatory borders, whereas the red channel showed faintly discernible lesions without clear margins. FAF revealed diffuse hyperautofluorescence but lacked precise border delineation. In the resolving stage, lesion hyperintensity progressively diminished on the green channel, while red channel visibility decreased significantly. FAF changes were subtle, with reduced autofluorescence intensity. Healed lesions exhibited isointense areas on the green channel with well-defined borders, while hyperpigmented regions appeared as hypointense patches on the red channel. FAF showed uniformly dark zones corresponding to healed areas. Retinal vascular abnormalities were more prominently detected on the green channel compared with other imaging modalities. The blend function in UWFI offers a novel, stage-wise characterization of choroiditis, with the green channel providing superior delineation of active inflammatory lesions compared with FAF. The red channel serves as an adjunct in assessing disease resolution. This imaging approach enhances diagnostic accuracy and facilitates objective disease monitoring, potentially improving clinical decision-making in inflammatory chorioretinal disorders.