New Concepts for the Diagnosis of Polypoidal Choroidal Vasculopathy

Abstract

Polypoidal choroidal vasculopathy (PCV) is a subtype of neovascular age-related macular degeneration (nAMD) that is characterized by a branching neovascular network and polypoidal lesions. It is important to differentiate PCV from typical nAMD as there are differences in treatment response between subtypes. Indocyanine green angiography (ICGA) is the gold standard for diagnosing PCV; however, ICGA is an invasive detection method and impractical for extensive use for regular long-term monitoring. In addition, access to ICGA may be limited in some settings. The purpose of this review is to summarize the utilization of multimodal imaging modalities (color fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), and fundus autofluorescence (FAF)) in differentiating PCV from typical nAMD and predicting disease activity and prognosis. In particular, OCT shows tremendous potential in diagnosing PCV. Characteristics such as subretinal pigment epithelium (RPE) ring-like lesion, en face OCT-complex RPE elevation, and sharp-peaked pigment epithelial detachment provide high sensitivity and specificity for differentiating PCV from nAMD. With the use of more practical, non-ICGA imaging modalities, the diagnosis of PCV can be more easily made and treatment tailored as necessary for optimal outcomes.

Keywords: OCT; PCV; color fundus photograph; en face OCT-complex RPE elevation; non-ICGA; sharp-peaked PED; sub-RPE ring-like lesion.

Figure 1

Typical potential diagnostic features detected using CFP and OCT. (A) Subretinal orange nodule on CFP (yellow arrow); (B) Sub-RPE ring-like lesion (yellow arrow) and thick choroid with dilated Haller’s layer (blue arrow); (C) Sharp-peaked/thumb-like PED (yellow arrow); (D) Notched/multilobular PED (yellow arrow); (E) Double-layer sign (yellow arrow); (F). En face OCT complex RPE elevation.

Figure 2

Examples of OCT and OCTA findings in eyes with PCV. (A) Structural OCT showing thumb-like PED (yellow arrow) and DLS (blue arrowhead); (B) Localized hyperflow sub-RPE signal (red overlay) underneath PED (yellow arrow) observed on cross-sectional OCTA. (C,D) Early (C) and late phase (D) of ICGA, both polyp (yellow arrow) and BVN (blue arrowhead) can be seen in ICGA; (E) En face OCT showed complex subretinal vascular structure with hyperreflective borders (yellow arrow); (F) In the corresponding position on en face OCTA, a nodular hyperflow lesion was seen (yellow arrow), with an adjacent BVN (blue arrowhead).