Purpose: To analyze type 1 neovascular membranes in age-related macular degeneration (AMD) using optical coherence tomography (OCT) angiography, to correlate morphologic characteristics with imaging and clinical criteria, and to analyze structural features of type 1 neovascularization sequentially after anti-vascular endothelial growth factor (VEGF) therapy.
Design: Prospective interventional case series.
Methods: Macular OCT angiography images were acquired using the RTVue XR Avanti with AngioVue. Distinct morphologic patterns and quantifiable features of the neovascular membranes were studied on en face projection images at baseline and follow-up.
Results: Thirty-three eyes of 25 patients were included. In 75% of the eyes, a highly organized vascular complex could be identified. A large main central vessel trunk/feeder vessel could be seen in 72% of these eyes, with vessels radiating in a branching pattern either in all directions from the center of the lesion ("medusa" pattern), or from one side of the lesion ("seafan" pattern). Of the 18 eyes with follow-up OCT angiography, the lesion area and vessel density remained unchanged, even after anti-vascular endothelial growth factor (VEGF) therapy, indicating a more mature longstanding neovascular complex resistant to anti-VEGF therapy.
Conclusions: OCT angiography provides a unique opportunity to study the morphology of occult type 1 neovascular membranes in AMD and allows precise structural and vascular assessment noninvasively. We identified a large mature neovascular complex in approximately 75% of eyes, typically consisting of a feeder vessel and large branching vessels resistant to anti-VEGF therapy. OCT angiography may better guide evaluation and treatment of neovascular AMD, and may contribute to the development of improved therapies.
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