DIGITAL INDOCYANINE-GREEN VIDEOANGIOGRAPHY OF OCCULT CHOROIDAL NEOVASCULARIZATION

Background: Occult choroidal neovascularization (CNV) secondary to age -related macular degeneration occurs in the majority of patients with exudative maculopathy. Since occult CNV cannot be imaged clearly by fl uorescein angiography, this condition is untreatable. The authors perf ormed digital indocyanine-green videoangiography (ICG-V) on 657 consec utive eyes with occult CNV by fluorescein angiography to determine if this technique could be useful in enhancing the imaging of the neovasc ularization, and thus increasing treatment eligibility. Materials and Methods: Six hundred fifty-seven consecutive eyes with occult CNV were studied. The fluorescein and ICG angiograms were compared, and the pe rcentage of patients potentially eligible for laser therapy based on I CG findings was calculated. Results: Of 413 eyes with occult CNV witho ut pigment epithelial detachments, focal areas of neovascularization w ere noted in 89 (22%). Overall, 142 (34.3%) eyes had lesions that were potentially treatable by laser photocoagulation based on additional i nformation provided by ICG-V. Of the 235 eyes with occult CNV and vasc ularized pigment epithelial detachments, 98 (42%) were eligible for la ser therapy based on ICG-V findings. The authors calculate that ICG-V enhances the treatment eligibility by approximately one third. Conclus ions: In diagnosing occult CNV, ICG-V is an important adjunctive techn ique to fluorescein angiography. This technique is especially useful i n delineating occult neovascularization, neovascularization with overl ying subretinal hemorrhage or serosanguineous fluid, and neovasculariz ation associated with pigment epithelial detachments. The authors curr ently suggest that ICG-V be performed in eyes in which well-delineated neovascularization cannot be identified by fluorescein angiography. B ased on their preliminary study, it can be expected that one in three patients with occult CNV potentially will be eligible for laser photoc oagulation based on ICG-V. Further studies are necessary to confirm th ese findings.