Optical Coherence Tomography Angiography of Indocyanine Green Angiographic Plaques in Asymptomatic Intermediate Age-Related Macular Degeneration

Abstract

Objective

To correlate images from swept source optical coherence tomography microangiography (SS-OMAG) with images from fluorescein angiography (FA) and indocyanine green angiography (ICGA) performed on asymptomatic eyes with intermediate age-related macular degeneration.

Study Design and Methods

A retrospective, observational, consecutive case series of patients with asymptomatic, intermediate AMD in one eye and neovascular AMD in their fellow eye. The patients underwent SS-OMAG, FA, and ICGA, and the images obtained from these three angiographic techniques were compared.

Results

Three patients were identified with intermediate AMD in one eye and symptomatic, neovascular AMD in their fellow eye. The three asymptomatic eyes had drusen and pigmentary abnormalities in the central macula and no evidence of macular fluid on OCT imaging. One patient presented with minimal leakage on FA from the asymptomatic eye. ICGA revealed the presence of central macular plaques, and SS-OMAG revealed type 1 neovascularization corresponding to the plaques. The type 1 neovascularization was visualized using en face slabs that extended from the border of the outer retina to the choriocapillaris (CC), 8 μm beneath Bruch’s membrane.

Conclusions

SS-OMAG identified type 1 neovascularization within ICGA plaques. The ability of OCTA to provide non-invasive, fast, detailed, depth-resolved identification of non-exudative neovascular lesions in eyes with intermediate AMD suggests the need for new terminology that distinguishes between non-exudative intermediate AMD and non-exudative, neovascular intermediate AMD. This distinction should prove useful for managing AMD patients at risk for conversion to late, exudative AMD once natural history studies are performed to better understand disease progression.