High-precision, high-accuracy ultralong-range swept-source optical coherence tomography using vertical cavity surface emitting laser light source

We demonstrate ultralong-range swept-source optical coherence tomography (OCT) imaging using vertical cavity surface emitting laser technology. The ability to adjust laser parameters and high-speed acquisition enables imaging ranges from a few centimeters up to meters using the same instrument. We discuss the challenges of long-range OCT imaging. In vivo human-eye imaging and optical component characterization are presented. The precision and accuracy of OCT-based measurements are assessed and are important for ocular biometry and reproducible intraocular distance measurement before cataract surgery. Additionally, meter-range measurement of fiber length and multicentimeter-range imaging are reported. 3D visualization supports a class of industrial imaging applications of OCT.National Institutes of Health (U.S.) (R01-EY011289-26)National Institutes of Health (U.S.) (R01 EY013178-12)National Institutes of Health (U.S.) (R01-EY013516-09)National Institutes of Health (U.S.) (R01-EY019029-03)National Institutes of Health (U.S.) (R01-CA075289-15)National Institutes of Health (U.S.) (R01-NS057476-05)National Institutes of Health (U.S.) (R44-CA101067-05)United States. Air Force Office of Scientific Research (FA9550-10-1-0551)United States. Air Force Office of Scientific Research (FA9550-10-1-0063

Imaging limbal and scleral vasculature using Swept Source Optical Coherence Tomography

We demonstrate application of high-speed swept source optical coherence tomography for vessel visualization in the anterior segment of the human eye. The human corneo-scleral junction and sclera was imaged in vivo. Imaging was performed using a swept source OCT system operating at 1050nm wavelength range and 100kHz A-scan rate. The high imaging speed enables generation of 3D depth-resolved vasculature maps. The vessel visualization method revealed the rich vascular system in the conjunctiva and episclera.National Institutes of Health (U.S.) (NIH grant R01-EY011289-25)National Institutes of Health (U.S.) (NIH grant R01-EY013178-11)National Institutes of Health (U.S.) (NIH grant R01-EY01356-06)National Institutes of Health (U.S.) (NIH grant R01 CA075289-15)United States. Air Force Office of Scientific Research (FA9550-10-1-0551)United States. Air Force Office of Scientific Research (FA9550-10-1-0063)Foundation for Polish Science (KOLUMB Programme; KOL/3/2010I

Reproducibility of a Long-Range Swept-Source Optical Coherence Tomography Ocular Biometry System and Comparison with Clinical Biometers

Objective To demonstrate a novel swept source optical coherence tomography (SS-OCT) imaging device using a vertical cavity surface-emitting laser (VCSEL) capable of imaging the full eye length and to introduce a method using this device for noncontact ocular biometry. To compare the measurements of intraocular distances using this SS-OCT instrument with commercially available optical and ultrasound biometers. To evaluate the intersession reproducibility of measurements of intraocular distances using SS-OCT. Design Evaluation of technology. Participants Twenty eyes of 10 healthy subjects imaged at the New England Eye Center at Tufts Medical Center and Massachusetts Institute of Technology between May and September 2012. Methods Averaged central depth profiles were extracted from volumetric SS-OCT datasets. The intraocular distances, such as central corneal thickness (CCT), aqueous depth (AD), anterior chamber depth (ACD), crystalline lens thickness (LT), vitreous depth (VD), and axial length (AL), were measured and compared with a partial coherence interferometry device (IOLMaster; Carl Zeiss Meditec, Inc., Dublin, CA) and an immersion ultrasound (IUS) A-scan biometer (Axis-II PR; Quantel Medical, Inc., Cournon d'Auvergne Cedex, France). Main Outcome Measures Reproducibility of the measurements of intraocular distances, correlation coefficients, and intraclass correlation coefficients. Results The standard deviations of the repeated measurements of intraocular distances using SS-OCT were 6 μm (CCT), 16 μm (ACD), 14 μm (AD), 13 μm (LT), 14 μm (VD), and 16 μm (AL). Strong correlations among all 3 biometric instruments were found for AL (r > 0.98). The AL measurement using SS-OCT correlates better with the IOLMaster (r=0.998) than with IUS (r=0.984). The SS-OCT and IOLMaster measured higher AL values than ultrasound (175 and 139 μm, respectively). No statistically significant difference in ACD between the optical (SS-OCT or IOLMaster) and ultrasound methods was detected. High intersession reproducibility of SS-OCT measurements of all intraocular distances was observed with intraclass correlation coefficients >0.99. Conclusions The SS-OCT using VCSEL technology enables full eye length imaging and high-precision, noncontact ocular biometry. The measurements with the prototype SS-OCT instrument correlate well with commercial biometers. The SS-OCT biometry has the potential to provide clinically useful comprehensive biometric parameters for pre- and postoperative eye evaluation.National Institutes of Health (U.S.) (Grant R01-EY011289-27)National Institutes of Health (U.S.) (Grant R01-EY013178-12)National Institutes of Health (U.S.) (Grant R01-EY013516-09)National Institutes of Health (U.S.) (Grant R01-EY019029-04)National Institutes of Health (U.S.) (Grant R44EY022864-01)National Institutes of Health (U.S.) (Grant R01-CA075289-16)National Institutes of Health (U.S.) (Grant R01-NS057476-05)National Institutes of Health (U.S.) (Grant R44CA101067-05)United States. Air Force Office of Scientific Research (Grant FA9550-10-1-0551)United States. Air Force Office of Scientific Research (Grant FA9550-10-1-0063)Thorlabs, Inc

En Face Enhanced-Depth Swept-Source Optical Coherence Tomography Features of Chronic Central Serous Chorioretinopathy

Objective To characterize en face features of the retinal pigment epithelium (RPE) and choroid in eyes with chronic central serous chorioretinopathy (CSCR) using a high-speed, enhanced-depth swept-source optical coherence tomography (SS-OCT) prototype. Design Consecutive patients with chronic CSCR were prospectively examined with SS-OCT. Participants Fifteen eyes of 13 patients. Methods Three-dimensional 6×6 mm macular cube raster scans were obtained with SS-OCT operating at 1050 nm wavelength and 100 000 A-lines/sec with 6 μm axial resolution. Segmentation of the RPE generated a reference surface; en face SS-OCT images of the RPE and choroid were extracted at varying depths every 3.5 μm (1 pixel). Abnormal features were characterized by systematic analysis of multimodal fundus imaging, including color photographs, fundus autofluorescence, fluorescein angiography, and indocyanine-green angiography (ICGA). Main Outcome Measures En face SS-OCT morphology of the RPE and individual choroidal layers. Results En face SS-OCT imaging at the RPE level revealed absence of signal corresponding to RPE detachment or RPE loss in 15 of 15 (100%) eyes. En face SS-OCT imaging at the choriocapillaris level showed focally enlarged vessels in 8 of 15 eyes (53%). At the level of Sattler's layer, en face SS-OCT documented focal choroidal dilation in 8 of 15 eyes (53%) and diffuse choroidal dilation in 7 of 15 eyes (47%). At the level of Haller's layer, these same features were observed in 3 of 15 eyes (20%) and 12 of 15 eyes (80%), respectively. In all affected eyes, these choroidal vascular abnormalities were seen just below areas of RPE abnormalities. In 2 eyes with secondary choroidal neovascularization (CNV), distinct en face SS-OCT features corresponded to the neovascular lesions. Conclusions High-speed, enhanced-depth SS-OCT at 1050 nm wavelength enables the visualization of pathologic features of the RPE and choroid in eyes with chronic CSCR not usually appreciated with standard spectral domain (SD) OCT. En face SS-OCT imaging seems to be a useful tool in the identification of CNV without the use of angiography. This in vivo documentation of the RPE and choroidal vasculature at variable depths may help elucidate the pathophysiology of disease and can contribute to the diagnosis and management of chronic CSCR.National Institutes of Health (U.S.) (R01-EY011289-27)National Institutes of Health (U.S.) (R01-EY013178-12)National Institutes of Health (U.S.) (R01-EY018184-05)National Institutes of Health (U.S.) (R44EY022864-01)National Institutes of Health (U.S.) (GR01-CA075289-16)National Institutes of Health (U.S.) (R01-NS057476-05)National Institutes of Health (U.S.) (R44-EY022864-01)United States. Air Force Office of Scientific Research (FA9550-10-1-0551)United States. Air Force Office of Scientific Research (FA9550-10-1-0063)Research to Prevent Blindness, Inc. (United States)Massachusetts Lions ClubGerman Science Foundation (DFG-GSC80-SAOT

Enhanced Vitreous Imaging in Healthy Eyes Using Swept Source Optical Coherence Tomography

Purpose To describe enhanced vitreous imaging for visualization of anatomic features and microstructures within the posterior vitreous and vitreoretinal interface in healthy eyes using swept-source optical coherence tomography (SS-OCT). The study hypothesis was that long-wavelength, high-speed, volumetric SS-OCT with software registration motion correction and vitreous window display or high-dynamic-range (HDR) display improves detection sensitivity of posterior vitreous and vitreoretinal features compared to standard OCT logarithmic scale display. Design Observational prospective cross-sectional study. Methods Multiple wide-field three-dimensional SS-OCT scans (500×500A-scans over 12×12 mm2) were obtained using a prototype instrument in 22 eyes of 22 healthy volunteers. A registration motion-correction algorithm was applied to compensate motion and generate a single volumetric dataset. Each volumetric dataset was displayed in three forms: (1) standard logarithmic scale display, enhanced vitreous imaging using (2) vitreous window display and (3) HDR display. Each dataset was reviewed independently by three readers to identify features of the posterior vitreous and vitreoretinal interface. Detection sensitivities for these features were measured for each display method. Results Features observed included the bursa premacularis (BPM), area of Martegiani, Cloquet's/BPM septum, Bergmeister papilla, posterior cortical vitreous (hyaloid) detachment, papillomacular hyaloid detachment, hyaloid attachment to retinal vessel(s), and granular opacities within vitreous cortex, Cloquet's canal, and BPM. The detection sensitivity for these features was 75.0% (95%CI: 67.8%–81.1%) using standard logarithmic scale display, 80.6% (95%CI: 73.8%–86.0%) using HDR display, and 91.9% (95%CI: 86.6%–95.2%) using vitreous window display. Conclusions SS-OCT provides non-invasive, volumetric and measurable in vivo visualization of the anatomic microstructural features of the posterior vitreous and vitreoretinal interface. The vitreous window display provides the highest sensitivity for posterior vitreous and vitreoretinal interface analysis when compared to HDR and standard OCT logarithmic scale display. Enhanced vitreous imaging with SS-OCT may help assess the natural history and treatment response in vitreoretinal interface diseases.Massachusetts Lions Eye Research Fund, Inc.Research to Prevent Blindness, Inc. (United States)United States. Air Force Office of Scientific Research (grant FA9550-1010551)United States. Air Force Office of Scientific Research (grant FA9550-12-1-0499)German Research Foundation (DFG-HO-1791/11-1)German Research Foundation (DFGGSC80-SAOT)German Research Foundation (DFG Research Training Group 1773)Champalimaud Foundation (Champalimaud Vision Award Fund)National Institutes of Health (U.S.) (R01- EY11289-28)National Institutes of Health (U.S.) (R01-CA075289-16)National Institutes of Health (U.S.) (R44-EY022864-01

Volumetric macro- and micro-scale assessment of crystalline lens opacities in cataract patients using long-depth-range swept source optical coherence tomography

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement. This manuscript version is made available under the CC-BY 4.0 license http://creativecommons.org/licenses/by/4.0/ This document is the Published Manuscript version of a Published Work that appeared in final form in Biomedical Optics Express. To access the final edited and published work see https://doi.org/10.1364/BOE.9.003821We demonstrate an optimized optical platform for the three-dimensional (3-D) visualization of crystalline lens opacities in vivo in the eyes of patients with different types and grades of cataracts. We developed a prototype long-depth-range swept source optical coherence tomography (SS-OCT) instrument operating at the speed of 50 kA-scans/second and at the central wavelength of 1 μm to perform high-resolution imaging of the whole anterior segment of the eye. Volumetric data sets of cataractous eyes were acquired and processed to obtain contrast-enhanced high-resolution images of lenticular structures and opacifications. The results showed lens micro- and macro-scale features related to possible cataract development such as cortical spokes, water clefts and enhanced scattering in the lens nucleus. The results demonstrate also the ability of this SS-OCT imaging to locate and characterize opacities quantitatively. The instrument might be a useful tool in the high-resolution preoperative evaluation of crystalline lens opacities in cataract patients

Reproducibility of in-vivo OCT measured three-dimensional human lamina cribrosa microarchitecture

Purpose: To determine the reproducibility of automated segmentation of the three-dimensional (3D) lamina cribrosa (LC) microarchitecture scanned in-vivo using optical coherence tomography (OCT). Methods: Thirty-nine eyes (8 healthy, 19 glaucoma suspects and 12 glaucoma) from 49 subjects were scanned twice using swept-source (SS-) OCT in a 3.5x3.5x3.64 mm (400x400x896 pixels) volume centered on the optic nerve head, with the focus readjusted after each scan. The LC was automatically segmented and analyzed for microarchitectural parameters, including pore diameter, pore diameter standard deviation (SD), pore aspect ratio, pore area, beam thickness, beam thickness SD, and beam thickness to pore diameter ratio. Reproducibility of the parameters was assessed by computing the imprecision of the parameters between the scans. Results: The automated segmentation demonstrated excellent reproducibility. All LC microarchitecture parameters had an imprecision of less or equal to 4.2%. There was little variability in imprecision with respect to diagnostic category, although the method tends to show higher imprecision amongst healthy subjects. Conclusion: The proposed automated segmentation of the LC demonstrated high reproducibility for 3D LC parameters. This segmentation analysis tool will be useful for in-vivo studies of the LC. © 2014 Wang et al

Data for the manuscript entitled 'Age-related changes in geometry and transparency of the human crystalline lens revealed by optical signal discontinuity zones in swept-source OCT images'

The file includes the data presented in the manuscript entitled &#39;Age-related changes in geometry and transparency of the human crystalline lens revealed by optical signal discontinuity zones in swept-source OCT images&#39; by A. Gupta et al. The aim of the study was to characterize the age-related changes in the morphology and transparency of the optical signal discontinuity (OSD) zones in the eye lenses of healthy subjects and to investigate the association of those changes with the optical quality of the eye and with visual function. The spreadsheets include:(1) demographic and ophthalmic information about the recruited subjects(2) the morphology measurements from the OCT images. It comprises the measured thickness of the whole lens, whole cortex and OSD zones as well as radii of curvature (ROC) of the anterior lens, anterior nucleus, posterior nucleus and posterior lens. (3) the optical density measurements from the OCT images of the whole lens, whole cortex and OSD zones. It also includes measurements optical scattering index (OSI), area under logarithmic contrast sensitivity function (AULCSF), visual acuity (VA) from OQAS system and VAO system. (4) thickness measurements of anterior and posterior OSD zones excluding the nucleus.</p

Data for the manuscript entitled 'Dynamic corneal response for different air-puff stimuli in ex vivo animal model measured with SS-OCT system with two sample arms'

The file contains data presented in the manuscript &#34;Dynamic corneal response for different air-puff stimuli in ex vivo animal model measured with SS-OCT system with two sample arms&#34; by E. Maczynska-Walkowiak et al.The aim of the study was to evaluate how the spatial and temporal characteristics of custom air pulses influence the dynamic displacement of the ex vivo porcine corneal surface under various IOP levels. The file is divided into 6 spreadsheets:1) Spatial and temporal characterization of the air puffs (Types 1-3);2) Example of dynamic corneal response of the porcine eye ex vivo to Type 1 air puff;3) Optimization of the measurement - impact of multiple stimulations on dynamic corneal response;4) Quantification of dynamic corneal response for different levels of intraocular pressure (IOP);5) Representative hysteresis loops for IOP &#61; 15 mmHg and IOP &#61; 30 mmHg for all types of air puffs;6) Corneal velocity profiles for different IOP levels.</p

Data for the manuscript entitled 'Corneal dynamics in normal, forme fruste and keratoconic eyes measured with air-puff OCT-based optical biometry'

The file includes the data presented in the manuscript entitled &#39;Corneal dynamics in normal, forme fruste and keratoconic eyes measured with air-puff OCT-based optical biometry&#39; by P. Mlyniuk et al. The study aimed at characterizing the differences in corneal dynamic response in normal eyes, forme fruste eyes and keratoconus eyes using air-puff OCT-based optical biometry. We also determined the impact of age, intraocular pressure , and corneal geometry on the air-puff-induced deformation of the cornea in each group. For each measured group of participants the spreadsheet includes baseline characteristics (age, IOP, subjective refraction, anterior chamber depth ACD, simulated keratometry SimK, keratometry cylinder Kcyl, central corneal thickness CCT, thinnest corneal thickness TCT, central epithelium thickness CET, minimum and maximum epithelium thickness ET within the 10-mm diameter zone) as well as quantitative biomarkers of air-puff-induced corneal dynamics:1)     maximum corneal displacement (MCD);2)     duration of corneal displacement (DD) at half maximum of displacement;3)     the ratio of the area under the corneal displacement curve during loading relative to the area under the corneal displacement curve during recovery (L/R).4)     the velocity of corneal apex displacement represented by two extremes: CVL and CVR;5)     the time between two extremes of the velocity of corneal apex displacement (Δtv);6)     hysteresis area (HA);7)     the slope of the load curve in the displacement-force cycle from 10 to 90% of MCD (SL). The slope of the recovery to the equilibrium in the displacement-force cycle from 10 to 90% of MCD (SR).</p