Optical Coherence Tomography Angiography Features of Type 3 Neovascularization in Age-Related Macular Degeneration

Purpose: To characterize the imaging features of type 3 neovascularization secondary to exudative age-related macular degeneration on optical coherence tomography (OCT) angiography (OCTA).

Methods: Patients diagnosed with treatment-naïve early-stage type 3 neovascularization underwent multimodal imaging, including color retinal photography or multicolor imaging, fluorescein angiography, indocyanine green angiography, spectral-domain OCT and OCTA. The OCTA features of type 3 neovascularization were analyzed and correlated with the findings on angiography and spectral-domain OCT.

Results: OCTA showed lesions characterized by a retinal-retinal anastomosis. These lesions emerged from the deep capillary plexus and formed a clear, tuft-shaped, high-flow network in the outer retinal segment in all eyes, abutting in the subretinal pigment epithelium space. In most cases, a small, clew-like lesion was present in the choriocapillaris segment. Moreover, in some cases, this clew-like lesion seemed to be connected to the choroid through a small-caliber vessel.

Conclusion: OCTA of treatment-naïve type 3 neovascularization shows high-flow, tuft-shaped, abnormal outer retinal proliferation that is almost consistently associated with a small, clew-like lesion in the choriocapillaris layer.