Tomographic features of idiopathic polypoidal choroidal vasculopathy using spectral domain OCT

Abstract

Purpose: To study the tomographic features of idiopathic polypoidal choroidal vasculopathy (IPCV) diagnosed on indocyanine green (ICG) angiogram using spectral domain optical coherence tomography (SDOCT). Design: This was a retrospective observational case series. Materials and Methods: Spectral domain optical coherence tomography (SD OCT) features of 50 eyes of 50 consecutive patients diagnosed as idiopathic polypoidal choroidal vasculopathy (IPCV) between January 2013 to January 2015 on ICG angiograms were studied. A qualitative analysis based on various tomographic features corresponding to the polypoidal lesions and branching vascular network on Spectrailis OCT was studied. Polyps were localized to subfoveal and juxtafoveal areas. These were later compared with SDOCT features of 15 eyes of 15 consecutive patients newly diagnosed as occult choroidal neovascular membrane (CNVM) on FFA/ICG. Results: Of the 50 eyes, sharp peak pigment epithelial notch (PED) was present in 49 eyes (98%); PED notch in 49 eyes (98%); a visible hyporeflective lumen with hyperreflective lesions adherent to the outer surface of the RPE in 48 eyes (96%), multiple PED in 44 eyes (80%), and diffuse PED in 44 eyes (80%); intraretinal hyperreflective dots representing hard exudates were seen in 44 eyes (88%). Surrounding OCT features such as intraretinal hyperreflective dots represent hard exudates, Cystoid macular edema and subretinal fluid were seen in 44 eyes (88%). Sub-RPE features such as PED with sheaths of internal reflectivity – branching vascular network in 19 eyes (38%) and prominent Bruchs membrane and surfacing of choroidal vessels was seen in 18 eyes (36%). At least 3 of the abovementioned OCT features were seen in all of the eyes diagnosed as PCV. The height of the PED ranged from 138–1300 μ (median = 422.2 μ). Of the 15 eyes, 80% showed presence of FVPED; multiple PED were seen in 33.3%; intraretinal hard exudates in 66.7%, and notch PED in 6.7%. Hyporeflective lumen with hyperreflective lesion under RPE was not seen in any of the eyes. The height of PED ranged from 118–339 μ (median = 164.28 μ). Conclusions: SDOCT-based features mentioned above allows detection of IPCV and differentiate it from occult CNVM. Our results suggest that SDOCT may be a useful noninvasive tool compared to ICG in detecting PCV, especially in places where ICG is not available or is contraindicated.