Purchase this article with an account.
Qinqin Zhang, Ruikang Wang; Optical coherence tomography angiography based capillary velocimetry on human retina. Invest. Ophthalmol. Vis. Sci. 2019;60(11):001. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the capillary velocimetry on human retina based on optical coherence tomography angiography (OCTA) scanning protocol (B-M mode)
A 1060 nm swept source OCTA engine (PLEX® Elite 9000 (ZEISS, Dublin, CA)) running at 100 kHz A-line rate with motion tracking mechanism was utilized in our study. A new scanning protocol with 110 A-lines x 110 B-scans covering ~ 1mm x 1mm with 10 repetitions was designed and implemented on the device for velocimetry calculation. The frame rate is up to 500 frames per second with a distinguishable velocity from 0 mm/s to ~0.5mm/s according to the theorical analysis. Eigen decomposition (ED) based capillary velocimetry was used to extract the blood flow speed information of the capillary in human retina. Retinal and choroidal layer were segmented to investigate different pathologies, including the whole retinal layer extending from ILM to outer border of OPL for retinal diseases and the ORCC layer for choroidal neovascularization (CNV) cases. All the patients were imaged with a 3x3mm OCTA scan and then focused on the diseased region by using the velocimetry scanning protocol with a small field of view. Color mapping was used to display the speed variations of blood flow
Normal eyes, diabetic retinopathy (DR) eyes and CNV eyes were enrolled to evaluate the algorithm. Overall all eyes showed blood flow speed variations. In pathological eyes, abnormal blood flow speeds were observed compared to normal controls. A faster speed associated with the trunk of the CNV lesion and slower speeds associated with the lesion extremities was observed in CNV eyes. In DR patients, slower speeds were observed in capillary loops that associated with microaneurysms and as well as the suspended scattering particle in motion (SSPiM)
A novel method for capillary velocimetry was proposed to visualize the relative blood flow speed in capillary level on human retina. The modified scanning protocol ensured a sufficient scanning speed based on a commercially available SSOCTA to differentiate the blood flow speed in a certain range, particularly in capillary level. This velocimetry method may play a role in not only studying the ocular disease but also in developing endpoints for therapeutic trials
This abstract was presented at the 2019 ARVO Imaging in the Eye Conference, held in Vancouver, Canada, April 26-27, 2019.
This PDF is available to Subscribers Only