Abstract
Abstract: :
Purpose:To study the fundus morphology under Indocyanine Green Angiography(ICGA) in diabetic retinopathy and compare it with that under flourescein angiography(FA). Methods:95 diabetic patients, 146 eyes underwent color fundus photography, simutaneous FA and ICGA(Heidelberg Engineering). The Microaneurysm(MA), retinal hemorrhage, hard exudate, cotton wool were compared between FA and ICGA. Results:1. Under FA, MA leakage began in early phase and most of them could not be clearly visualized in late phase because of the leakage and stain. Under ICGA, MA were not easy to be visualized in early phase due to the strong background fluorescence, they were clearer in late phase. Some of the MA also leaked under ICGA and the leakage were slower and in smaller extent than that under FA. 2. Thick retinal hemorrhage and hard exudate both blocked the background fluorescence under ICGA and FA. Thin retinal hemorrhage could not be detected under ICGA. Hard exudates were clearer to be visualized in late phase under ICGA than FA. 3. None perfusion with or without cotton wool could be detected under FA. Under ICGA, only none perfusion with cotton wool could be detected. In some of the eyes, none perfusion areas could not be detected because of the mask of retinal hemorrhage, but the observation for none perfusion with cotton wool was less affected under ICGA when thin retinal hemorrhage coexisted. 4. Under ICGA, part of the eyes showed diffuse hyperfluorescence spots in late phase, hyper- and hypo-fluorescence(salt and pepper appearance) in very late phase. Conclusions: 1. ICGA could be an adjunct to FA to detect the diabetic damage at retinal level especially when media opacity, retinal hemorrhage and contraindication for FA exist. 2. Just as ICG has been used to stain inter-limiting membrane in vitreous surgery, the diffuse hyperfluorescence or hyper- and hypo-fluorescence appearance might be caused by the selective staining of fundus tissue since ICG could leak through MA as it was found in this study.
Keywords: diabetic retinopathy • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S • imaging/image analysis: clinical