Comparison of SD-OCT and OCT-Angiography Features in Presumed Choroidal Neovascularization in the AVATAR study

Abstract

Purpose : Spectral domain optical coherence tomography (SD-OCT) is the current standard imaging modality for monitoring exudative activity secondary to choroidal neovascular tissue (CNV) in patients with macular disease. Optical coherence tomography angiography (OCT-A) is an emerging modality that allows direct visualization of flow within CNV vessels. It is not known how the detection of CNV by OCT-A compares with detection of choroidal neovascular exudation by SD-OCT. The purpose of this study was to evaluate the comparative features of the two modalities in eyes with presumed CNV.

Methods : This was an IRB-approved prospective observational study examining OCT-A in eyes undergoing SD-OCT for macular disease, the AVATAR study. All patients were imaged with the Avanti RTVue XR HD (Optovue, Fremont, CA) and the Cirrus HD-OCT system (Zeiss, Oberkochen, Germany). The Avanti system was equipped with prototype SSADA algorithm software to generate segmented retinal OCT-A scans. Images were reviewed by a masked expert reviewer. SD-OCT scans were assessed for intraretinal fluid, subretinal fluid, subretinal hyperreflective material, and subretinal pigment epithelial material. OCT-A scans were assessed for the presence or absence of CNV, defined as flow signal in the outer retina and/or abnormal vascular flow in the choroid.

Results : A total of 81 eyes were imaged. Thirty-five eyes had subretinal and/or intraretinal fluid on SD-OCT while 46 were negative for fluid. Of the eyes with positive fluid on SD-OCT, 69% (24/35) had CNV on OCT-A, 14% (5/35) did not have CNV on OCT-A, and 17% (6/35) were indeterminate. Of the eyes with negative fluid on SD-OCT, 30% (14/46) had CNV on OCT-A, 50% (23/46) did not have CNV on OCT-A, and 20% (9/46) were indeterminate.

Conclusions : OCT-A provides a unique opportunity for visualization of CNV in eyes with macular disease. OCT-A may predict active flow within CNV in the absence of exudative signs on SD-OCT. Further research is needed to better delineate the specific roles for OCT-A in the management of CNV.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

SD-OCT and OCT-angiography of eyes with presumed choroidal neovascularization (CNV). 3x3-mm OCT-A scans were segmented at the choriocapillaris. (a) Subretinal fluid on SD-OCT (arrows) corresponds to CNV on OCT-A. (b) Intraretinal fluid is positive on SD-OCT (arrows) but there is no CNV on OCT-A. (c) CNV can be seen on OCT-A but SD-OCT fluid is negative.