Comparison of indocyanine green and fluorescein angiography of choroidal neovascularization

We compared indocyanine green (ICG) and fluorescein angiography for evaluation of choroidal neovascularization (CNV). Cast preparations of CNV induced in monkey eyes by laser photocoagulation were correlated with ICG and fluorescein angiographies of the same CNV formations. Fluorescein angiography was more effective, in general, than ICG angiography in detecting CNV; however, CNVs with subretinal hemorrhage (2 of 35 sites) were visible only with ICG angiography. In early phase ICG angiography, CNV formations that casts showed to be dense or composed of thick vessels were seen, but less dense areas were not visible. Lesions that ICG angiography revealed as leaking were not differentiated morphologically from non-leaking areas by the CNV casts. This study confirms that only ICG angiography can identify CNV hidden by subretinal hemorrhage, although fluorescein angiography is otherwise superior. Indocyanine green angiography is indicated as a valuable complement to fluorescein angiography for evaluation of CNV.