We demonstrate ultrahigh speed spectral / Fourier domain optical coherence tomography (OCT) using an ultrahigh speed CMOS line scan camera at rates of 70,000 -312,500 axial scans per second. Several design configurations are characterized to illustrate trade-offs between acquisition speed, resolution, imaging range, sensitivity and sensitivity roll-off performance. Ultrahigh resolution OCT with 2.5 -3.0 micron axial image resolution is demonstrated at ∼ 100,000 axial scans per second. A high resolution spectrometer design improves sensitivity roll-off and imaging range performance, trading off imaging speed to 70,000 axial scans per second. Ultrahigh speed imaging at >300,000 axial scans per second with standard image resolution is also demonstrated. Ophthalmic OCT imaging of the normal human retina is investigated. The high acquisition speeds enable dense raster scanning to acquire densely sampled volumetric three dimensional OCT (3D-OCT) data sets of the macula and optic disc with minimal motion artifacts. Imaging with ∼ 8 -9 micron axial resolution at 250,000 axial scans per second, a 512 × 512 × 400 voxel volumetric 3D-OCT data set can be acquired in only ∼ 1.3 seconds. Orthogonal registration scans are used to register OCT raster scans and remove residual axial eye motion, resulting in 3D-OCT data sets which preserve retinal topography. Rapid repetitive imaging over small volumes can visualize small retinal features without motion induced distortions and enables volume registration to remove eye motion. Cone photoreceptors in some regions of the retina can be visualized without adaptive optics or active eye tracking. Rapid repetitive imaging of 3D volumes also provides dynamic volumetric information (4D-OCT) which is shown to enhance visualization of retinal capillaries and should enable functional imaging. Improvements in the speed and performance of 3D-OCT volumetric imaging promise to enable earlier diagnosis and improved monitoring of disease progression and response to therapy in ophthalmology, as well as have a wide range of research and clinical applications in other areas. 1.IntroductionAn increasingly important tool for medical diagnosis and biomedical research, Optical Coherence Tomography (OCT) enables two and three dimensional visualization of the internal structure and morphology of tissue [1]. High sensitivity, large dynamic range, and micron level resolution imaging are achieved with OCT by interferometric detection of backscattered light from the sample. In ophthalmology, OCT can perform non-invasive structural and quantitative NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript imaging of the retina and anterior segment, which enables the identification of pathologies for disease diagnosis or monitoring responses to therapy [2].The earliest implementations of OCT used low coherence interferometry with time domain detection in which the echo delay of backscattered light was measured by mechanically sweeping a mirror in a reference arm [3,4,5]. Commercial ophtha...

Purpose To demonstrate ultrahigh-speed optical coherence tomography (OCT) imaging of the retina and optic nerve head at 249,000 axial scans per second and a wavelength of 1060 nm. To investigate methods for visualization of the retina, choroid, and optic nerve using high-density sampling enabled by improved imaging speed. Methods A swept-source OCT retinal imaging system operating at a speed of 249,000 axial scans per second was developed. Imaging of the retina, choroid, and optic nerve were performed. Display methods such as speckle reduction, slicing along arbitrary planes, en face visualization of reflectance from specific retinal layers, and image compounding were investigated. Results High-definition and three-dimensional (3D) imaging of the normal retina and optic nerve head were performed. Increased light penetration at 1060 nm enabled improved visualization of the choroid, lamina cribrosa, and sclera. OCT fundus images and 3D visualizations were generated with higher pixel density and less motion artifacts than standard spectral/Fourier domain OCT. En face images enabled visualization of the porous structure of the lamina cribrosa, nerve fiber layer, choroid, photoreceptors, RPE, and capillaries of the inner retina. Conclusions Ultrahigh-speed OCT imaging of the retina and optic nerve head at 249,000 axial scans per second is possible. The improvement of ∼5 to 10× in imaging speed over commercial spectral/Fourier domain OCT technology enables higher density raster scan protocols and improved performance of en face visualization methods. The combination of the longer wavelength and ultrahigh imaging speed enables excellent visualization of the choroid, sclera, and lamina cribrosa.

PURPOSE-To report the frequency of optical coherence tomography (OCT) scan artifacts and compare macular thickness measurements, inter-scan reproducibility and inter-device agreeability across three spectral / Fourier domain (SD) OCTs (Cirrus HD-OCT, RTVue-100 and Topcon 3D-OCT 1000) and one time domain (TD) OCT (Stratus OCT). METHODS-Two scans were performed for each of the SD-OCT protocols: Cirrus macular cube 512×128, RTVue (E)MM5 and MM6, Topcon 3D macular and radial, in addition to one TD-OCT scan via Stratus macular thickness protocol. Scans were inspected for six types of OCT scan artifacts and analyzed. Inter-scan reproducibility and inter-device agreeability were assessed by intraclass correlation coefficients (ICCs) and Bland-Altman plots, respectively. DESIGN-ProspectiveMAIN OUTCOME MEASURE-OCT image artifacts, Macular thickness, Reproducibility, Agreeability.RESULTS-TD-OCT scans contained a significantly higher percentage of clinically significant improper central foveal thickness (IFT) post-manual correction (greater than or equal to 11 μm

PURPOSE-To describe the features of intraretinal retinal pigment epithelium (RPE) migration documented on a prototype spectral domain high speed, ultrahigh resolution optical coherence tomography (OCT) device in a group of patients with early to intermediate dry age-related macular degeneration (AMD). To correlate intraretinal RPE migration on OCT to RPE pigment clumping on fundus photographs. DESIGN-Retrospective, non-comparative, non-interventional case series. PARTICIPANTS-Fifty METHODS-3DOCT scan sets from all patients were analyzed for presence of intraretinal RPE migration, defined as small discreet hyper-reflective and highly-backscattering lesions within the neurosensory retina. Fundus photographs were also analyzed to determine the presence of RPE pigment clumping, defined as black-colored, often spiculated areas of pigment clumping within the macula. OCT en face images were correlated with fundus photographs to demonstrate correspondence of intraretinal RPE migration on OCT and RPE clumping on fundus photo.MAIN OUTCOME MEASURES-Drusen, Dry AMD, intraretinal RPE migration, RPE pigment clumping.© 2010 American Academy of Ophthalmology, Inc. Published by Elsevier Inc. All rights reserved.Corresponding Author/ Reprints: Jay S. Duker, MD, Department of Ophthalmology, Chairman, Tufts Medical Center, 800 Washington St., Box #450, Boston, MA, 02111, Tel: 617-636-4677; Fax: 617-636-4866, JDuker@tuftsmedicalcenter.org. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. DisclosuresThe sponsors had no role in the design or conduct of this research. Authors with financial/conflicting interests are listed after references. NIH Public Access Author ManuscriptOphthalmology. Author manuscript; available in PMC 2012 April 1. The area of intraretinal RPE migration on OCT always correlated to areas of pigment clumping on fundus photography. Conversely, all but one eye with RPE pigment clumping on fundus photography also had areas of intraretinal RPE migration on OCT. The high incidence of intraretinal RPE migration observed above areas of drusen suggests that drusen may play physical and catalytic roles in facilitating intraretinal RPE migration in dry AMD patients.