Characterization of leakage activity in exudative chorioretinal disease with three-dimensional confocal angiography.

ABSTRACT

PURPOSE: A novel angiographic technique providing topographic imaging of chorioretinal fluorescence is applied to the characterization of leakage dynamics in exudative chorioretinopathy. The three-dimensional imaging is evaluated with respect to results with conventional two-dimensional fluorescence angiography. DESIGN: Prospective observational case series. PARTICIPANTS: Thirty eyes of 30 patients with different exudative maculopathies (pigment epithelium detachment, branch retinal vein occlusion, central serous chorioretinopathy, each n = 10) and 11 eyes of 10 patients with clinically normal appearance. METHODS: Depth-resolved fluorescence angiography using a confocal scanning laser system was performed after complete ophthalmologic examination. The axial distribution of fluorescein and indocyanine green fluorescence at each x/y position within a tomographic scan of 32 images was analyzed. The chorioretinal fluorescence topography was reconstructed by localizing a defined threshold value of fluorescence and displayed as topographic relief. Qualitative description and quantitative measurements of exudation or structural alterations were performed topographically and conventionally. MAIN OUTCOME MEASURES: Qualitative and quantitative analysis of structural or exudative changes in time course in topographic illustration compared with conventional angiography. RESULTS: Clinically physiologic eyes were presented topographically as a smooth concave surface of fluorescence with defined illustration of retinal vascular structures and the optic disc. Retinal vascular pathologic conditions induce a precisely demarcated pattern of intraretinal edema with a characteristic temporal evolution. In central serous retinopathy the underlying pathologic condition was identified as a perfusion defect, which was subsequently filled with a peak of exudation with differences in the time of maximum in fluorescein/indocyanine green angiography. Pigment epithelium detachment appeared as a high and well defined elevation, with the origin of exudation within the base of the detachment. Differences in the time of maximum prominence were found in indocyanine green angiography within the pigment epithelium detachment group. CONCLUSIONS: Confocal topographic angiography allows for the first time precise three-dimensional functional imaging of fundus alterations caused by leakage or barrier dysfunction. Compared with conventional angiography, depth-resolved angiographic imaging is less impaired by masking phenomena or low fluorescence intensity, which improves the diagnostic yield of angiography. The characterization and quantification of leakage activity is a promising tool in the assessment of exudative maculopathy.