Abstract
Purpose:
To measure the change in size of choroidal neovascularization (CNV) in response to anti-vascular endothelial growth factor (VEGF) treatment measured using a spectral domain optical coherence tomography angiography (SD-OCTA) system.
Methods:
Eight eyes from eight patients diagnosed with CNV who underwent OCTA pre and post-treatment with anti-VEGF agents were enrolled. One eye was treatment-naïve. Each eye was imaged prior to treatment and scanned at multiple follow up visits using the prototype AngioVue OCTA system applying a split-spectrum amplitude decorrelation angiography (SSADA) algorithm on a SD-OCT device (Optovue Inc, Fremont, CA). The system operated at 70,000 A-scans per second to acquire OCTA volumes of 304 x 304 A-scans. Orthogonal registration and merging of two consecutive image sets were used to obtain OCT angiograms. OCTA volumes were segmented into 30-50 micrometer-thick en-face segments demonstrating the dimensions of the CNV. Trained readers at the Boston Image Reading Center measured the greatest linear dimension and the area of the CNV in the pre-treatment and post-treatment images. The primary outcomes of the study were greatest linear dimension and area of the CNV. Secondary outcomes included the appearance of CNV (well-circumscribed versus poorly circumscribed), the presence of subretinal and/or intraretinal fluid on OCT B-scan, and visual acuity.
Results:
Eight eyes of eight patients with CNV were scanned with the OCTA system. Ages ranged from 31 - 85 and included four males and four females. Etiology of CNV included age-related macular degeneration, multifocal choroiditis and central serous chorioretinopathy. 50 % of eyes had significant reduction in the length and area of the CNV after treatment as well as resolution of subretinal fluid. 25 % had no change in the size of the CNV and no change in amount of subretinal fluid present.
Conclusions:
CNV size measured using OCTA may decrease after successful anti-VEGF treatment. No change in the size of the CNV may suggest resistance to anti-VEGF agents. Optical coherence tomography angiography may be a useful tool for monitoring and quantifying the response of choroidal neovascularization to treatment.