Abstract
Abstract: :
Purpose: Indocyanine green (ICG) angiography (ICGA) seems available to examine the choroidal vascular lesions in Vogt-Koyanagi-Harada (VKH) disease. However, the interpretation of the ICGA findings is sometimes confusing for the following reasons. Since the structure of the choroidal vasculature is three dimensional, it is difficult to localize the vascular lesion, accurately. In addition, the fast velocity of the choroidal circulation makes it difficult to detect the vascular lesions especially in the early dye transit phase. To circumvent these problems, we tried to analyze the ICGA findings by using the subtraction method. Methods: Eight patients diagnosed as having the VKH disease were examined by the ICGA before and after steroid therapy. Subtraction image analysis was performed with a Topcon IMAGEnet computer system. The selected two images from a series of ICGA were aligned by marking identical points on each image. The ICG angiogram taken in the earlier phase was subtracted from those taken in the later phase. Results: Before steroid therapy, the ICG subtraction revealed the hyperfluorescence corresponding to the intrachoroidal leakage of ICG in the dye transit phase. By contrast, such hyperfluorescence became diminished after steroid therapy. Conclusion: Taken together, the ICG subtraction is useful to evaluate the effect of steroid therapy in the VKH disease.
Keywords: 612 uveitis-clinical/animal model • 345 choroid • 331 blood supply