OCT angiography offers dual advantage of imaging structure, blood flow

KOLOA, Hawaii — State-of-the-art of optical coherence tomography angiography in 2017 is for diagnosis and management of neovascularization, according to a speaker here.

“It’s a single device, two modalities,” Jay S. Duker, MD, said at Retina 2017. “And once you get over the initial cost of buying OCTA, there’s really not a lot of added cost. It’s a few seconds of chair time per eye.”

OCT angiography allows clinicians to view both the structure and blood flow of the retinal and choroidal tissue simultaneously via three-dimensional angiograms, providing a tool for diagnosing neovascularization and other abnormalities.

It also allows distinction of specific depths in the tissue, including the superficial inner retina, deep inner retina, outer retina and choriocapillaris.

“So you can figure out what depth you’re at, provided there are no artifacts,” said Duker.

“I think it’s great for confirming the presence of choroidal neovascularization, I think especially type 1 and type 3 CNVs,” he said.

He added that OCTA can also detect the presence of type 2 macular telangiectasia, retinal vein occlusion, microaneurysms and macular ischemia.

The technology is available in the U.S. from Carl Zeiss Meditech and Optovue, and in Europe and Asia from Nidek, according to Duker.

“Zeiss has the Cirrus 5000 and their software is called the AngioPlex, available right now. Optovue’s hardware is called the Avanti; their software is called AngioVue, available right now. Nidek also has OCTA. As far as I know it’s still not approved in the United States,” he said.

The technology does have limitations, Duker said.

“I am still not ready to say that it is helpful in deciding [on] treatment criteria...I don’t think we’ve worked it out well enough to really make retreatment decisions based on OCTA,” he said.

Duker also said it is difficult to view the periphery with OCTA because the resolution lessens as the imaging widens. Artifacts present another challenge, although companies provide software to eliminate them. But clinicians should be cautious when addressing artifact.

“If you’re eliminating something that you think is noise, there’s a threshold there, and you may actually be eliminating real signal too, so you have to be careful with these add-on softwares.” – by Joe Green

Reference: Duker J. Introduction to optical coherence tomography angiography (OCTA). Presented at: Retina 2017; Jan. 16-20, 2017; Koloa, Hawaii.

Disclosure: Duker reports he receives research support and is a consultant for Carl Zeiss Meditech, Optovue and Topcon.