Multicolor Fundus Imaging of Polypoidal Choroidal Vasculopathy

Abstract

Polypoidal choroidal vasculopathy (PCV) is a variant of neovascular age-related macular degeneration with distinct phenotypes, treatment, and visual prognosis. Multicolor imaging is a novel noninvasive imaging method that enables visualization of structures located at different layers of the retina and may be useful in detecting features of diseases. The features of PCV seen on multicolor imaging have not been studied. We aimed to describe the features of PCV detected using multicolor imaging and to compare these with standard color fundus photography (CFP). Hospital-based, cross-sectional study. Fifty consecutive treatment-naive patients diagnosed with PCV seen in a tertiary referral center. Multimodal imaging was performed using standardized protocols, and included CFP, multicolor imaging, fluorescein angiography, and indocyanine green angiography (ICGA). The CFP and ICGA images were independently graded by reading center-certified retinal specialists to confirm the diagnosis of PCV and identify lesion components. The features of the lesion components seen on multicolor images were compared with those detected using CFP and ICGA. Frequency and features of lesions associated with PCV, specifically, polyps, branching vascular network (BVN), pigment epithelial detachments (PEDs), hemorrhages, and drusen. The mean age of the 50 participants was 67.9 years, and 60% were male. Polyps were most clearly seen on the infrared reflectance image and detected in 49 of 50 eyes (98%), appearing as dark gray oval lesions with distinct margins. On the multicolor composite images, polyps appeared as dark green oval lesions. The BVN appeared as mottled gray regions on infrared reflectance imaging and were seen less frequently compared with polyps (30/50 eyes, 60%). The margins of the BVN were less distinct compared with polyps. Other clinical features detected using multicolor imaging included PEDs (26%), subretinal hemorrhages (40%), and drusen (66%). Multicolor imaging is able to detect polypoidal lesions in most patients with PCV. The appearance of PCV lesions on multicolor imaging differs from standard CFP, although the location and shape of lesions correlate well with features seen on CFP and ICGA. Multicolor imaging is a useful, noninvasive adjunct to detect features suggestive of PCV, which may prompt definitive investigations such as ICGA.