Toward a specific classification of polypoidal choroidal vasculopathy: Idiopathic disease or subtype of age-related macular degeneration

Purpose. To suggest a clinical distinction between idiopathic polypoidal choroidal vasculopathy (PCV) and secondary polyps associated with neovascular age-related macular degeneration (NV-AMD). Methods. The study was a retrospective case series of 52 eyes of 52 consecutive patients (31 females and 21 males) diagnosed with PCV. Initial diagnosis was based on scanning laser ophthalmoscope–indocyanine green angiography (SLO-ICGA) in association with fluorescein angiography (FA) and optical coherence tomography (OCT). All the data and images were analyzed in a masked fashion by four experienced examiners in two different sessions: the first, to classify patients into the two hypothesized groups (idiopathic polyps or NV-AMD–related polyps); the second, following a predetermined scheme, to describe objective features. The results obtained in each session underwent a cross multivariate analysis to identify statistically significant differences (P ≤ 0.05) between the two groups. Results. The two groups were clinically different on the basis of FA (leakage origin [P = 0.001] and presence of drusen [P = 0.001]), ICGA (evidence of choroidal neovascularization [CNV; P = 0.001] and/or branching vascular network [BVN; P = 0.001]), OCT imaging (type of pigmented epithelium detachment [P = 0.001], presence of BVN [P = 0.001], and subfoveal choroidal thickness [P = 0.001]). Further significant differences were observed according to the location of lesion (uni- or multifocal) (P = 0.001), type of CNV (P = 0.001), and best-corrected visual acuity (P = 0.001). Conclusions. Our study demonstrated clinical and statistically significant differences between idiopathic PCV and NV-AMD–related polyps that could be considered as distinct entities. Although they share some similarities, mainly the sub-RPE location, the ability to identify a specific clinical pattern suggests a more specific therapeutic approach for these two entities.