Membrane patterns in eyes with choroidal neovascularization on optical coherence tomography angiography

To evaluate morphologic patterns of choroidal neovascular membranes using optical coherence tomography angiography (OCTA) in patients with treatment-naive, continuously treated, and previously treated exudative age-related macular degeneration (AMD).

We assessed retrospectively 184 eyes of 153 patients diagnosed with type 1, type 2, and mixed-type neovascularization associated with AMD. The type of neovascularization and clinical activity were assessed by clinical examination and spectral domain optical coherence tomography (SD-OCT). Morphological patterns of neovascular membranes were categorized using en face images on the AngioVue (Optovue) OCTA system.

The mean age of patients was 77.9 ± 8.6 years (range, 52-96 years). The most frequently identified type of membrane morphology was well-defined in the treatment-naive group (69% of the eyes) and in eyes receiving ongoing anti-VEGF treatments (77% of the eyes). Long-filamentous morphology was the most frequent type in the previously treated group (53%), in which only 33% had a well-defined membrane. All clinically active cases had a well-defined pattern, such as a medusa or sea-fan shaped pattern, or an ill-defined pattern, and none had a long-filamentous neovascular network. Almost half of the clinically inactive cases (47%) had well- or ill-defined, identifiable membrane morphology on OCTA. A long-filamentous membrane pattern, which was consistent with chronicity of lesion, was seen only in eyes with inactive neovascularization.

The membrane morphology on OCTA was not associated with clinical activity, except that the presence of long dilated filamentous linear vessels was associated with chronicity and lesion inactivity.