Optical coherence tomography angiography of type 3 neovascularisation in age-related macular degeneration after antiangiogenic therapy

Background/aims To assess the microvascular response of type 3 neovascularisation secondary to age-related macular degeneration (AMD) after antivascular endothelial growth factor (anti-VEGF) therapy using optical coherence tomography angiography (OCTA). Methods Consecutive patients diagnosed with AMD and type 3 neovascularisation based on clinical examination, structural optical coherence tomography and fluorescein angiography when available were retrospectively evaluated. En face OCTA imaging (3x3 mm scans) with quantitative microvascular analysis was performed at baseline and after a single anti-VEGF intravitreal injection. Results 17 eyes of 14 patients underwent OCTA before and after anti-VEGF treatment. OCTA demonstrated significant regression of small calibre type 3 neovascular tufts in all eyes. Median lesion area was 0.061 mm(2) (range 0.003-0.198 mm(2)) at baseline and 0.009 mm(2) (range 0-0.085 mm(2), p=0.0003) at follow-up. Cystoid macular oedema and/or subretinal fluid resolved in all cases after treatment. The type 3 lesions became undetectable with OCTA post-treatment in 5 of the 17 eyes. However, in 11 eyes, large feeder vessels were identified and remained unchanged after treatment. Conclusions The microvascular morphology of type 3 neovascularisation secondary to AMD was assessed at baseline and follow- up and showed significant regression in response to anti-VEGF therapy by OCTA. Quantitative OCTA analysis was also performed and confirmed remarkable regression in response to a single intravitreal anti-VEGF injection.