Angiographic lesion of polypoidal choroidal vasculopathy on indocyanine green and fluorescein angiography

Background Before treating polypoidal choroidal vasculopathy (PCV), the extent of the lesion should be determined, but the angiographic lesion size of PCV is sometimes different when comparing indocyanine green angiography (ICGA) and fluorescein angiography (FA). The purpose of this study was to evaluate angiographic findings and compare the lesion sizes of PCV on ICGA and FA using confocal scanning laser ophthalmoscopy (SLO) and fundus camera. Methods Thirty-seven eyes of 37 patients with PCV were examined by ICGA and FA using confocal SLO and a fundus camera, and the findings and the lesion sizes were compared during the early, mid, and late-phases of ICGA and FA. Results The polyps with abnormal vessel networks were depicted on ICGA in all eyes and the lesion showed classic-type leakage on FA in 15 eyes. Ten eyes with a pigment epithelial detachment (PED) had the maximal lesion size on FA because hyperfluorescent areas involving PED were determined as the lesions; although on ICGA, a PED distinguished from abnormal vessels was not included in the lesion. In 27 eyes without a PED, the early-phase of ICGA using confocal SLO showed the maximal lesion size in 24 eyes (89%) and the late-phase in three eyes (11%), and the maximal size on ICGA agreed on FA. While FA depicted the maximal lesion sizes in 24 eyes (89%), another three eyes showed the maximal lesion size on early-phase ICGA on confocal SLO. The maximal lesion size on ICGA using a fundus camera was smaller than when using confocal SLO in seven eyes (19%). Conclusions The ICGA on confocal SLO could visualize the more detailed findings of the abnormal vasculature of PCV and the FA showed hyperfluorescent regions overlaying the lesions. To determine the maximal lesion size on angiograms, early-phase ICGA using confocal SLO and FA should be referred.