Abstract
Abstract: :
Purpose: To document extent and intensity of retinal vascular alteration in branch retinal vein occlusion (BRVO) using a novel three-dimensional angiographic technique. Methods: Fluorescein-and indocynanine green angiography (FA/ICGA) were performed in 33 patients within 3 months following BRVO, and in 12 patients before and following focal laser coagulation. A scanning laser ophthalmoscope (Heidelberg Retina Angiograph, HRA) was used for confocal serial imaging. 32 tomographic sections over a depth of 4 mm were recorded within 1.2 seconds. The axial fluorescence profile was determined for each image point resulting in a three-dimensional angiographic topography of perfusion and leakage phenomena. Areas and prominence of retinal thickening due to intraretinal fluid accumulation were measured. Results: Retinal areas affected by BRVO were clearly documented in their dimension and intensity by 75% of early and 84% of late three-dimensional FA and 84% of early and 89% of late 3D-ICGA series. Zones of BRVO imposed as well-delineated regions with distinct prominence exceeding the surrounding choriocapillary surface. Heights were quantified based on vertical and horizontal cross-sectional images. The mean size of the area presenting intraretinal leakage was 19.2 mm2 in FA and 18,4 mm in ICGA. A mean prominence of retinal extravasation of 373.3 µm was measured with best representation by early FA. In the 12 eyes who received focal laser therapy pretreatment values of 20.4 mm2 in area and 429 µm in prominence were determined over the affected site. At 3 months following laser therapy the area presenting fluid accummulation was identical in size, but showed less prominent extravasation with an average area of 19 mm2 and a mean prominence of 267 µm. Conclusion: Topographic angiography allows a precise delineation of retinal vascular permeability changes. Extent and prominence of intraretinal leakage can be illustrated and quantified providing important information for diagnosis and a standardized evaluation of therapeutic effects. Grid coagulation significantly decreases intraretinal fluid accummulation.
Keywords: 615 vascular occlusion/vascular occlusive disease • 430 imaging/image analysis: clinical • 356 clinical (human) or epidemiologic studies: systems/equipment/techniques