Evaluation of different OCT systems in quantitative imaging of human Schlemm's canal.
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ABSTRACT:
SUBMITTER: Wu X
PROVIDER: S-EPMC8792050 | biostudies-literature | 2022 Jan
REPOSITORIES: biostudies-literature
Publications
Evaluation of different OCT systems in quantitative imaging of human Schlemm's canal.
Wu Xuan X Tan Bingyao B Gan Jinyuan J Lam Adeline R AR Chen Yibing Y Liu Xinyu X Chua Jacqueline J Wong Damon W K DWK Ang Marcus M Schmetterer Leopold L Yao Xinwen X
Scientific reports 20220126 1
We examined the performance of human Schlemm's canal (SC) imaging using different OCT devices: CIRRUS 5000 (840 nm, spectral-domain (SD)-OCT), PLEX Elite 9000 (1060 nm, swept-source (SS)-OCT) and CASIA SS-1000 (1310 nm, SS-OCT), and analyzed potential impact factors on visualization and the quantitative assessment of SC morphology in a pilot study. Ten healthy subjects were imaged using three OCT devices by a single experienced operator on the same day. Each eye underwent two cubic scans by each ...[more]
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Project description:PurposeTo validate the ability of visible-light optical coherence tomography (vis-OCT) in imaging the full Schlemm's canal (SC) and its surrounding limbal vascular network in mice in vivo through a compound circumlimbal scan.MethodsWe developed an anterior segment vis-OCT system and a compound circumlimbal scanning method, which montages eight rotated raster scans. We calibrated the circumlimbal scan geometry using a three-dimensional printed phantom eyeball before imaging wild-type C57BL/6J mice. We measured SC size by segmenting SC cross sections from vis-OCT B-scan images and imaged the limbal microvascular network using vis-OCT angiography (vis-OCTA). To introduce changes in SC size, we used a manometer to adjust the intraocular pressure (IOP) to different levels. To create additional optical scattering contrast to enhance SC imaging, we surgically increased the episcleral venous pressure (EVP) and caused blood reflux into SC.ResultsUsing the compound circumlimbal scan, our anterior segment vis-OCT noninvasively imaged the full SC and limbal microvascular network in mouse for the first time. We observed an average 123% increase in SC volume when we decreased the IOP by 10 mm Hg from the baseline IOP of 7 to 10 mm Hg and an average 72% decrease in SC volume when the IOP level was elevated by 10 mm Hg from the baseline IOP. We also observed location-dependent SC size responses to IOP changes. Blood reflux caused by increased EVP enabled vis-OCTA to directly visualize SC, which matched well with the segmented SC.ConclusionsVis-OCT and vis-OCTA can accurately image the entire SC and limbal microvascular network in vivo using the compound circumlimbal scan. Vis-OCT is also able to quantitatively measure SC responses to changing IOP levels.
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