Indocyanine green angiography in chorioretinal diseases: indications and interpretation

The pathogenesis of central serous chorioretinopathy (CSC) is poorly understood. Abnormalities in the choroidal circulation have been hypothesized to be causative factors. Fluorescein angiography has not been particularly useful in identifying specific choroidal defects in CSC, largely because of inherent limitations in imaging with this technique. Recent technologic advances in digital indocyanine green videoangiography allow enhanced imaging of the choroid and other subretinal structures in comparison with fluorescein angiography. We performed digital indocyanine green videoangiography in 29 consecutive eyes with CSC and compared our results with clinical and fluorescein angiographic findings. Several newly recognized subretinal abnormalities in CSC were noted with digital indocyanine green videoangiography, including (1) presumed hyperpermeability of the choroidal circulation surrounding active retinal pigment epithelial leaks, (2) additional focal and multifocal areas of presumed choroidal hyperpermeability not associated with abnormalities detectable by fluorescein angiography or clinical examination, and (3) multiple presumed "occult" serous retinal pigment epithelial detachments with a characteristic indocyanine green videoangiographic pattern. We suggest that the pathogenesis of CSC may be due to a choroidal vascular hyperpermeability with and without associated active pigment epithelial leaks and multiple presumed "occult" serous retinal pigment epithelial detachments. Based on these findings, a hypothetical model can be constructed related to the pathogenesis of CSC, beginning with choroidal abnormalities that secondarily affect the retinal pigment epithelium and neurosensory retina.

Although adverse reactions to indocyanine green (ICG) are known to occur, the dye has been used for more than 30 years in tests of cardiac and hepatic function, with a high level of safety. Improved digital video technology has renewed interest in the use of intravenous ICG in ophthalmic imaging. This report describes the authors' experience regarding the safety of ICG for digital angiography and their recommendations for its use in the ophthalmic setting. Digital ICG videoangiography was performed in 1226 consecutive patients, and 1923 ICG videoangiography tests were performed. A registry of adverse reactions to ICG was established. Criteria were used to define mild, moderate, and severe adverse reactions, and these data were recorded for every ICG study performed. There were three (0.15%) mild adverse reactions, four (0.2%) moderate reactions, and one (0.05%) severe adverse reaction. There were no deaths. This study documents the safety of intravenous ICG for use in ophthalmic videoangiography.

To expand the clinical spectrum of idiopathic polypoidal choroidal vasculopathy based on historical cases and newly recognized observations. A review of the previously reported 45 cases was carried out. An additional 20 cases were retrospectively reviewed to examine the clinical nature and course of idiopathic polypoidal choroidal vasculopathy. New observations on the clinical spectrum of idiopathic polypoidal choroidal vasculopathy were noted for demographic features, the nature and course of the vascular lesion, the possible association with intraocular inflammation, and the indocyanine green angiographic characteristics. Idiopathic polypoidal choroidal vasculopathy seems to be a distinct clinical entity that has a predilection for individuals of pigmented races. The disorder should be differentiated from typical choroidal neovascularization and other known choroidal degenerative, inflammatory, and ischemic disorders because of differences in clinical course and treatment.