PURPOSE. To evaluate a new angiographic technique that offers three-dimensional imaging of chorioretinal vascular diseases. METHODS. Fluorescein (FA) and indocyanine green angiography (ICGA) were performed using a confocal scanning laser ophthalmoscope. Tomographic series with 32 images per set were taken over a depth of 4 mm at an image frequency of 20 Hz. An axial analysis was performed for each x/y position to determine the fluorescence distribution along the z-axis. The location of the onset of fluorescence at a defined threshold intensity was identified and a depth profile was generated. The overall results of fluorescence topography were displayed in a gray scale-coded image and three-dimensional relief. RESULTS. Topographic angiography delineated the choriocapillary surface covering the posterior pole with exposed larger retinal vessels. Superficial masking of fluorescence by hemorrhage or absorbing fluid did not preclude detection of underlying diseases. Choroidal neovascularization (CNV) appeared as a vascular formation with distinct configuration and prominence. Chorioretinal infiltrates exhibited perfusion defects with dye pooling. Retinal pigment epithelium detachments (PEDs) demonstrated dynamic filling mechanisms. Intraretinal extravasation in retinal vascular disease was detected within a well-demarcated area with prominent retinal thickening. CONCLUSIONS. Confocal topographic angiography allows highresolution three-dimensional imaging of chorioretinal vascular and exudative diseases. Structural vascular changes (e.g., proliferation) are detected in respect to location and size. Dynamic processes (e.g., perfusion defects, extravasation, and barrier dysfunction) are clearly identified and may be quantified. Topographic angiography is a promising technique in the diagnosis, therapeutic evaluation, and pathophysiological evaluation of macular disease. (Invest Ophthalmol Vis Sci. 2001;42: 2386 -2394 C horioretinal vascular disease of the macular area (e.g., diabetic maculopathy [DMP] and age-related macular degeneration [ARMD]) are the main reasons for progressive and severe visual loss by occlusive, proliferative, and/or exudative mechanisms. 1,2 Fluorescein angiography (FA) is the classic diagnostic tool but is often compromised by masking phenomena as a consequence of the short wavelength used. Diffuse leakage of the small fluorescein molecule causes further difficulties in identifying the origin and quantifying the dynamics of leakage. Despite stereoscopic viewing systems, many lesions remain occult, and prominence and extent of exudation are evaluated only subjectively. 2,3 Indocyanine green angiography (ICGA) is effective in the near-infrared spectrum which allows improved transmission, and, mostly bound to albumin, it is thought to extravasate minimally. 5-7 Scanning laser ophthalmoscopy (SLO), with point-source illumination and optimized excitation, has further enhanced diagnostic efficacy. 9,10 The option to scan through different retinal layers is nevertheless limited to a depth resolution of approximately 300 m. It may be used, however, to obtain topographic profiles of strongly reflecting intraocular structures, such as the optic disc and the macular region. 11 Morphometric imaging of vascular structures of retina and choroid would significantly improve the diagnosis of macular disease. A novel angiographic technology, confocal topographic angiography, has been developed that allows threedimensional (3-D) documentation of vascular structures and characterization of dynamic phenomena such as perfusion and leakage. The technique of topographic image processing was applied in the FA and ICGA analyses of representative types of chorioretinal vascular disease, to document structural and dynamic changes and to evaluate the diagnostic potential of the new method. MATERIALS AND METHODS The basic topographic principle is to use a series of lateral confocal optical sections of the chorioretinal fluorescence distribution and, by introducing a smart algorithm, to extract the 3-D profile of the surface of vascular structures and related leakage. Data acquisition was achieved with a conventional confocal scanning laser angiograph. Data processing and topographic analysis were performed on a standard desktop computer, using newly developed software. The method of confocal laser scanning topography based on ICGA has been published. 12,13 Data Acquisition FA and ICGA were performed using a confocal SLO (Heidelberg Retina Angiograph; Heidelberg Engineering, Dossenheim, Germany). Infrared images were taken for optical alignment with the fovea in the center of a 30°field corresponding to a retinal area of 9 ϫ 9 mm. For FA, 5 ml of 10% fluorescein solution (Alcon Pharma GmbH, Freiburg, Germany), an argon laser emitting at 488 nm for excitation, and filters blocking transmission of wavelengths below 510 nm were used for detection. For ICGA a 50-mg solution of ICG (ICG Pulsion, München, Germany) was administered intravenously, and excitation and detection were performed, using a diode laser emitting at 795 nm and blocking filters for wavelengths below 835 nm. The diameter of the excitation beam was 10 m at the retina. The Rayleigh range of the focal beam's waist determining depth resolution was 300 m. During the early transit phase, the scanning laser was focused onto the retinal vessels and the excitation intensity was adjusted to obtain adequate illumination. An additive ϩ3-diopter (D) refractive correction was added by using the internal focus adjustment to create a preretinal initial focus for complete sectioning of elevated lesions. An early FA/ICGA series of 32 tomographic sections was taken over a depth of 4 mm, each separated From th
