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Kurokawa K, Nemeth M. Multifunctional adaptive optics optical coherence tomography allows cellular scale reflectometry, polarimetry, and angiography in the living human eye. BIOMEDICAL OPTICS EXPRESS 2024; 15:1331-1354. [PMID: 38404344 PMCID: PMC10890865 DOI: 10.1364/boe.505395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 02/27/2024]
Abstract
Clinicians are unable to detect glaucoma until substantial loss or dysfunction of retinal ganglion cells occurs. To this end, novel measures are needed. We have developed an optical imaging solution based on adaptive optics optical coherence tomography (AO-OCT) to discern key clinical features of glaucoma and other neurodegenerative diseases at the cellular scale in the living eye. Here, we test the feasibility of measuring AO-OCT-based reflectance, retardance, optic axis orientation, and angiogram at specifically targeted locations in the living human retina and optic nerve head. Multifunctional imaging, combined with focus stacking and global image registration algorithms, allows us to visualize cellular details of retinal nerve fiber bundles, ganglion cell layer somas, glial septa, superior vascular complex capillaries, and connective tissues. These are key histologic features of neurodegenerative diseases, including glaucoma, that are now measurable in vivo with excellent repeatability and reproducibility. Incorporating this noninvasive cellular-scale imaging with objective measurements will significantly enhance existing clinical assessments, which is pivotal in facilitating the early detection of eye disease and understanding the mechanisms of neurodegeneration.
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Affiliation(s)
- Kazuhiro Kurokawa
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Research Institute, Legacy Health, Portland, OR 97232, USA
| | - Morgan Nemeth
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Research Institute, Legacy Health, Portland, OR 97232, USA
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2
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Georgiev S, Kumar A, Findl O, Hirnschall N, Niederleithner M, Kendrisic M, Drexler W, Leitgeb RA. Digital ocular swept source optical coherence aberrometry. BIOMEDICAL OPTICS EXPRESS 2021; 12:6762-6779. [PMID: 34858679 PMCID: PMC8606149 DOI: 10.1364/boe.430596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Ocular aberrometry is an essential technique in vision science and ophthalmology. We demonstrate how a phase-sensitive single mode fiber-based swept source optical coherence tomography (SS-OCT) setup can be employed for quantitative ocular aberrometry with digital adaptive optics (DAO). The system records the volumetric point spread function at the retina in a de-scanning geometry using a guide star pencil beam. Succeeding test-retest repeatability assessment with defocus and astigmatism analysis on a model eye within ± 3 D dynamic range, the feasibility of technique is demonstrated in-vivo at a B-scan rate of >1 kHz in comparison with a commercially available aberrometer.
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Affiliation(s)
- Stefan Georgiev
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria
- Contributed equally
| | - Abhishek Kumar
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Wavesense Engineering GmbH, Vienna, Austria
- Contributed equally
| | - Oliver Findl
- Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria
| | - Nino Hirnschall
- Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria
| | - Michael Niederleithner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Milana Kendrisic
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and Its Translation to Medicine, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
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3
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Lee KE, Heitkotter H, Carroll J. Challenges Associated With Ellipsoid Zone Intensity Measurements Using Optical Coherence Tomography. Transl Vis Sci Technol 2021; 10:27. [PMID: 34665233 PMCID: PMC8543396 DOI: 10.1167/tvst.10.12.27] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/16/2021] [Indexed: 12/11/2022] Open
Abstract
Translational Relevance Qualitative evaluation of the ellipsoid zone band on optical coherence tomography is a valuable clinical tool for assessing photoreceptor structure, though more quantitative metrics are emerging. Awareness of the challenges involved in interpreting quantitative metrics is important for their clinical translation.
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Affiliation(s)
- Karen E. Lee
- Medical College of Wisconsin, Milwaukee, WI, USA
| | - Heather Heitkotter
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Joseph Carroll
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
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4
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Three-dimensional composition of the photoreceptor cone layers in healthy eyes using adaptive-optics optical coherence tomography (AO-OCT). PLoS One 2021; 16:e0245293. [PMID: 33412568 PMCID: PMC7790532 DOI: 10.1371/journal.pone.0245293] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/25/2020] [Indexed: 12/18/2022] Open
Abstract
Purpose To assess the signal composition of cone photoreceptors three-dimensionally in healthy retinas using adaptive optics optical coherence tomography (AO-OCT). Methods Study population. Twenty healthy eyes of ten subjects (age 23 to 67). Procedures. After routine ophthalmological assessments, eyes were examined using AO-OCT. Three-dimensional volumes were acquired at 2.5° and 6.5° foveal eccentricity in four main meridians (superior, nasal, inferior, temporal). Cone densities and signal compositions were investigated in four different planes: the cone inner segment outer segment junction (IS/OS), the cone outer segment combined with the IS/OS (ISOS+), the cone outer segment tips (COST) and full en-face plane (FEF) combining signals from all mentioned cone layers. Additionally, reliability of a simple semi-automated approach for assessment of cone density was tested. Main outcome measures. Cone density of IS/OS, IS/OS+, COST and FEF. Qualitative depiction and composition of each cone layer. Inter-rater agreement of cone density measurements. Results Mean overall cone density at all eccentricities was highest at the FEF plane (21.160/mm2), followed by COST (20.450/mm2), IS/OS+ (19.920/mm2) and IS/OS (19.530/mm2). The different meridians and eccentricities had a significant impact on cone density, with lower eccentricity resulting in higher cone densities (p≤.001), which were highest at the nasal, then temporal, then inferior and then superior meridian. Depiction of the cone mosaic differed between all 4 layers regarding signal size and packing density. Therefore, different cone layers showed evident but not complete signal overlap. Using the semi-automated technique for counting of cone signals achieved high inter-rater reliability (ICC > .99). Conclusions In healthy individuals qualitative and quantitative changes in cone signals are found not only in different eccentricities and meridians, but also within different photoreceptor layers. The variation between cone planes has to be considered when assessing the integrity of cone photoreceptors in healthy and diseased eyes using adaptive optics technology.
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5
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Kanngiesser J, Roth B. Wavefront Shaping Concepts for Application in Optical Coherence Tomography-A Review. SENSORS (BASEL, SWITZERLAND) 2020; 20:E7044. [PMID: 33316998 PMCID: PMC7763956 DOI: 10.3390/s20247044] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 12/02/2020] [Accepted: 12/07/2020] [Indexed: 01/10/2023]
Abstract
Optical coherence tomography (OCT) enables three-dimensional imaging with resolution on the micrometer scale. The technique relies on the time-of-flight gated detection of light scattered from a sample and has received enormous interest in applications as versatile as non-destructive testing, metrology and non-invasive medical diagnostics. However, in strongly scattering media such as biological tissue, the penetration depth and imaging resolution are limited. Combining OCT imaging with wavefront shaping approaches significantly leverages the capabilities of the technique by controlling the scattered light field through manipulation of the field incident on the sample. This article reviews the main concepts developed so far in the field and discusses the latest results achieved with a focus on signal enhancement and imaging.
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Affiliation(s)
- Jonas Kanngiesser
- Hannoversches Zentrum für Optische Technologien, Leibniz Universität Hannover, Nienburger Straße 17, D-30167 Hannover, Germany;
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering–Innovation Across Disciplines), D-30167 Hannover, Germany
| | - Bernhard Roth
- Hannoversches Zentrum für Optische Technologien, Leibniz Universität Hannover, Nienburger Straße 17, D-30167 Hannover, Germany;
- Cluster of Excellence PhoenixD (Photonics, Optics, and Engineering–Innovation Across Disciplines), D-30167 Hannover, Germany
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6
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Ruiz-Lopera S, Restrepo R, Cuartas-Vélez C, Bouma BE, Uribe-Patarroyo N. Computational adaptive optics in phase-unstable optical coherence tomography. OPTICS LETTERS 2020; 45:5982-5985. [PMID: 33137049 PMCID: PMC8384075 DOI: 10.1364/ol.401283] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
We present a scheme for correction of x-y-separable aberrations in optical coherence tomography (OCT) designed to work with phase unstable systems with no hardware modifications. Our approach, termed SHARP, is based on computational adaptive optics and numerical phase correction and follows from the fact that local phase stability is sufficient for the deconvolution of optical aberrations. We demonstrate its applicability in a raster-scan polygon-laser OCT system with strong phase-jitter noise, achieving successful refocusing at depths up to 4 times the Rayleigh range. We also present in vivo endoscopic and ex vivo anterior segment OCT data, showing significant enhancement of image quality, particularly when combining SHARP results with a resolution-preserving despeckling technique like TNode.
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Affiliation(s)
| | - René Restrepo
- Applied Optics Group, Universidad EAFIT, Carrera 49 # 7 Sur-50, Medellín, Colombia
- Aerospace Optics Instrumentation Division, National Institute of Aerospace Technology, Ctra de Ajalvir, Km 4, 28850 Madrid, Spain
| | - Carlos Cuartas-Vélez
- Applied Optics Group, Universidad EAFIT, Carrera 49 # 7 Sur-50, Medellín, Colombia
| | - Brett E. Bouma
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
| | - Néstor Uribe-Patarroyo
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, 40 Blossom Street, Boston, Massachusetts 02114, USA
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7
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Shirazi MF, Brunner E, Laslandes M, Pollreisz A, Hitzenberger CK, Pircher M. Visualizing human photoreceptor and retinal pigment epithelium cell mosaics in a single volume scan over an extended field of view with adaptive optics optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2020; 11:4520-4535. [PMID: 32923061 PMCID: PMC7449740 DOI: 10.1364/boe.393906] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 07/13/2020] [Accepted: 07/17/2020] [Indexed: 05/18/2023]
Abstract
Using adaptive optics optical coherence tomography, human photoreceptors and retinal pigment epithelium (RPE) cells are typically visualized on a small field of view of ∼1° to 2°. In addition, volume averaging is required for visualizing the RPE cell mosaic. To increase the imaging area, we introduce a lens based spectral domain AO-OCT system that shows low aberrations within an extended imaging area of 4°×4° while maintaining a high (theoretical) transverse resolution (at >7 mm pupil diameter) in the order of 2 µm. A new concept for wavefront sensing is introduced that uses light mainly originating from the RPE layer and yields images of the RPE cell mosaic in a single volume acquisition. The capability of the instrument for in vivo imaging is demonstrated by visualizing various cell structures within the posterior retinal layers over an extended field of view.
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Affiliation(s)
- Muhammad Faizan Shirazi
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna, Waehringer Guertel 18-20,
A-1090 Vienna, Austria
| | - Elisabeth Brunner
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna, Waehringer Guertel 18-20,
A-1090 Vienna, Austria
| | - Marie Laslandes
- ALPAO 727 rue Aristide Bergès 38330
Montbonnot-Saint-Martin, France
| | - Andreas Pollreisz
- Department of Ophthalmology and Optometry,
Medical University of Vienna, Vienna, Waehringer Guertel 18-20, A-1090
Vienna, Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna, Waehringer Guertel 18-20,
A-1090 Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical
Engineering, Medical University of Vienna, Waehringer Guertel 18-20,
A-1090 Vienna, Austria
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8
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Reumueller A, Wassermann L, Salas M, Karantonis MG, Sacu S, Georgopoulos M, Drexler W, Pircher M, Pollreisz A, Schmidt-Erfurth U. Morphologic and Functional Assessment of Photoreceptors After Macula-Off Retinal Detachment With Adaptive-Optics OCT and Microperimetry. Am J Ophthalmol 2020; 214:72-85. [PMID: 31883465 DOI: 10.1016/j.ajo.2019.12.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 12/11/2019] [Accepted: 12/13/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE Limited information is available on morphologic and functional regeneration of photoreceptors after retinal detachment (RD) surgery. This observational clinical study compared morphologic and functional changes of cones after vitrectomy for macula-off retinal detachment. DESIGN Prospective, fellow-eye comparative case series. METHODS StudyPopulation: Five eyes after vitrectomy with gas for macula-off retinal detachment (retinal detachment eyes, RDE) and 5 healthy fellow eyes (HFE) of 5 patients (mean age 59.8 years, macula-off duration 0.5 days to 5.5 days). ObservationProcedures: Eyes were examined with adaptive-optics optical coherence tomography (AO-OCT), spectral-domain OCT (SDOCT), and microperimetry (MP) at 6 (baseline, BL) and 56 weeks (follow-up, FUP) after 23 gauge pars plana vitrectomy and SF6 gas tamponade. Eight corresponding regions at foveal eccentricities of 2.5° (ecc 2.5°) and 6.5° (ecc 6.5°) were analyzed in every eye. AO-OCT en face images and SD-OCT B-scans were graded regarding irregularity and loss of photoreceptor signals ranging from none to severe changes. The number of detectable cones at height of the inner-outer segment junction (IS/OS) and cone outer segment tips (COST) was counted manually in AO-OCT images. MP with a custom grid was used to assess retinal sensitivity at these locations. MainOutcomeMeasures: Cone density, cone pattern regularity and signal attenuation, retinal sensitivity. RESULTS In comparison to HFE, RDE showed highly irregular cone patterns in AO-OCT and irregular outer retinal bands in SDOCT. Despite significant improvement of cone pattern regularity compared to BL (P < .001), 63% of AO images showed remaining cone pattern irregularity and 45.5% of SDOCT B-scans showed severe signal reduction at FUP. In HFE, mean cone density retrieved from IS/OS and COST remained around 20,000/mm2 (ecc 2.5°) and 16,000/mm2 (ecc 6.5°) at BL and FUP. Cone density of RDE was significantly reduced and ranged between 200/mm2 and 15,600/mm2 (P < .001) at BL. Despite improvement at FUP (P < .001), mean cone density at IS/OS and COST was still lower compared to HFE and ranged between 7790 and 9555 cones/mm2 (P < .001). Mean retinal sensitivity of all measured locations remained 18 dB in HFE and was significantly lower in RDE, with 14.30 dB at BL and 14.64 dB at FUP. Both SDOCT grading and microperimetry sensitivity showed strong correlation with AO-OCT grading and cone density (rho values > 0.750). CONCLUSIONS The combination of AO-OCT, SDOCT, and microperimetry is a powerful tool to capture cone regeneration after vitreoretinal surgery. Our study shows that cone morphology and function improve within 56 weeks after RD surgery but structural and functional impairment is still present.
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Affiliation(s)
- Adrian Reumueller
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Lorenz Wassermann
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Matthias Salas
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | | | - Stefan Sacu
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Michael Georgopoulos
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Andreas Pollreisz
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
| | - Ursula Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
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9
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Leitgeb RA. En face optical coherence tomography: a technology review [Invited]. BIOMEDICAL OPTICS EXPRESS 2019; 10:2177-2201. [PMID: 31143489 PMCID: PMC6524600 DOI: 10.1364/boe.10.002177] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 03/01/2019] [Accepted: 03/05/2019] [Indexed: 05/20/2023]
Abstract
A review on the technological development of en face optical coherence tomography (OCT) and optical coherence microscopy (OCM) is provided. The terminology originally referred to time domain OCT, where the preferential scanning was performed in the en face plane. Potentially the fastest realization of en face image recording is full-field OCT, where the full en face plane is illuminated and recorded simultaneously. The term has nowadays been adopted for high-speed Fourier domain approaches, where the en face image is reconstructed from full 3D volumes either by direct slicing or through axial projection in post processing. The success of modern en face OCT lies in its immediate and easy image interpretation, which is in particular of advantage for OCM or OCT angiography. Applications of en face OCT with a focus on ophthalmology are presented. The review concludes by outlining exciting technological prospects of en face OCT based both on time as well as on Fourier domain OCT.
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Affiliation(s)
- R A Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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10
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Reumueller A, Schmidt-Erfurth U, Salas M, Sacu S, Drexler W, Pircher M, Pollreisz A. Three-Dimensional Adaptive Optics–Assisted Visualization of Photoreceptors in Healthy and Pathologically Aged Eyes. ACTA ACUST UNITED AC 2019; 60:1144-1155. [DOI: 10.1167/iovs.18-25702] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Adrian Reumueller
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Ursula Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Matthias Salas
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
| | - Stefan Sacu
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University Vienna, Vienna, Austria
| | - Andreas Pollreisz
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
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11
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Salas M, Augustin M, Felberer F, Wartak A, Laslandes M, Ginner L, Niederleithner M, Ensher J, Minneman MP, Leitgeb RA, Drexler W, Levecq X, Schmidt-Erfurth U, Pircher M. Compact akinetic swept source optical coherence tomography angiography at 1060 nm supporting a wide field of view and adaptive optics imaging modes of the posterior eye. BIOMEDICAL OPTICS EXPRESS 2018; 9:1871-1892. [PMID: 29675326 PMCID: PMC5905931 DOI: 10.1364/boe.9.001871] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/13/2018] [Accepted: 03/13/2018] [Indexed: 05/25/2023]
Abstract
Imaging of the human retina with high resolution is an essential step towards improved diagnosis and treatment control. In this paper, we introduce a compact, clinically user-friendly instrument based on swept source optical coherence tomography (SS-OCT). A key feature of the system is the realization of two different operation modes. The first operation mode is similar to conventional OCT imaging and provides large field of view (FoV) images (up to 45° × 30°) of the human retina and choroid with standard resolution. The second operation mode enables it to optically zoom into regions of interest with high transverse resolution using adaptive optics (AO). The FoV of this second operation mode (AO-OCT mode) is 3.0° × 2.8° and enables the visualization of individual retinal cells such as cone photoreceptors or choriocapillaris. The OCT engine is based on an akinetic swept source at 1060 nm and provides an A-scan rate of 200 kHz. Structural as well as angiographic information can be retrieved from the retina and choroid in both operational modes. The capabilities of the prototype are demonstrated in healthy and diseased eyes.
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Affiliation(s)
- Matthias Salas
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and Its Translation to Medicine, Medical University of Vienna, Vienna, Austria
| | - Marco Augustin
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | | | - Andreas Wartak
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Marie Laslandes
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Laurin Ginner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and Its Translation to Medicine, Medical University of Vienna, Vienna, Austria
| | - Michael Niederleithner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Jason Ensher
- INSIGHT Photonic Solutions, Inc., Lafayette, CO, USA
| | | | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and Its Translation to Medicine, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Drexler
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | | | - Ursula Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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12
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Ginner L, Schmoll T, Kumar A, Salas M, Pricoupenko N, Wurster LM, Leitgeb RA. Holographic line field en-face OCT with digital adaptive optics in the retina in vivo. BIOMEDICAL OPTICS EXPRESS 2018; 9:472-485. [PMID: 29552387 PMCID: PMC5854052 DOI: 10.1364/boe.9.000472] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/22/2017] [Accepted: 12/22/2017] [Indexed: 05/05/2023]
Abstract
We demonstrate a high-resolution line field en-face time domain optical coherence tomography (OCT) system using an off-axis holography configuration. Line field en-face OCT produces high speed en-face images at rates of up to 100 Hz. The high frame rate favors good phase stability across the lateral field-of-view which is indispensable for digital adaptive optics (DAO). Human retinal structures are acquired in-vivo with a broadband light source at 840 nm, and line rates of 10 kHz to 100 kHz. Structures of different retinal layers, such as photoreceptors, capillaries, and nerve fibers are visualized with high resolution of 2.8 µm and 5.5 µm in lateral directions. Subaperture based DAO is successfully applied to increase the visibility of cone-photoreceptors and nerve fibers. Furthermore, en-face Doppler OCT maps are generated based on calculating the differential phase shifts between recorded lines.
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Affiliation(s)
- Laurin Ginner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University of Vienna, Austria
| | | | - Abhishek Kumar
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Matthias Salas
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University of Vienna, Austria
| | - Nastassia Pricoupenko
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Lara M. Wurster
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
| | - Rainer A. Leitgeb
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Austria
- Christian Doppler Laboratory for Innovative Optical Imaging and its Translation to Medicine, Medical University of Vienna, Austria
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13
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Pircher M, Zawadzki RJ. Review of adaptive optics OCT (AO-OCT): principles and applications for retinal imaging [Invited]. BIOMEDICAL OPTICS EXPRESS 2017; 8:2536-2562. [PMID: 28663890 PMCID: PMC5480497 DOI: 10.1364/boe.8.002536] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/08/2017] [Accepted: 04/09/2017] [Indexed: 05/17/2023]
Abstract
In vivo imaging of the human retina with a resolution that allows visualization of cellular structures has proven to be essential to broaden our knowledge about the physiology of this precious and very complex neural tissue that enables the first steps in vision. Many pathologic changes originate from functional and structural alterations on a cellular scale, long before any degradation in vision can be noted. Therefore, it is important to investigate these tissues with a sufficient level of detail in order to better understand associated disease development or the effects of therapeutic intervention. Optical retinal imaging modalities rely on the optical elements of the eye itself (mainly the cornea and lens) to produce retinal images and are therefore affected by the specific arrangement of these elements and possible imperfections in curvature. Thus, aberrations are introduced to the imaging light and image quality is degraded. To compensate for these aberrations, adaptive optics (AO), a technology initially developed in astronomy, has been utilized. However, the axial sectioning provided by retinal AO-based fundus cameras and scanning laser ophthalmoscope instruments is limited to tens of micrometers because of the rather small available numerical aperture of the eye. To overcome this limitation and thus achieve much higher axial sectioning in the order of 2-5µm, AO has been combined with optical coherence tomography (OCT) into AO-OCT. This enabled for the first time in vivo volumetric retinal imaging with high isotropic resolution. This article summarizes the technical aspects of AO-OCT and provides an overview on its various implementations and some of its clinical applications. In addition, latest developments in the field, such as computational AO-OCT and wavefront sensor less AO-OCT, are covered.
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Affiliation(s)
- Michael Pircher
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Währinger Gürtel 18-20/4L, 1090 Vienna, Austria
| | - Robert J Zawadzki
- UC Davis RISE Eye-Pod Laboratory, Dept. of Cell Biology and Human Anatomy, University of California Davis, 4320 Tupper Hall, Davis, CA 95616, USA
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI) and Department of Ophthalmology and Vision Science, UC Davis, 4860 Y Street, Ste. 2400, Sacramento, CA 95817, USA
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14
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Salas M, Drexler W, Levecq X, Lamory B, Ritter M, Prager S, Hafner J, Schmidt-Erfurth U, Pircher M. Multi-modal adaptive optics system including fundus photography and optical coherence tomography for the clinical setting. BIOMEDICAL OPTICS EXPRESS 2016; 7:1783-96. [PMID: 27231621 PMCID: PMC4871081 DOI: 10.1364/boe.7.001783] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/21/2016] [Accepted: 04/01/2016] [Indexed: 05/03/2023]
Abstract
We present a new compact multi-modal imaging prototype that combines an adaptive optics (AO) fundus camera with AO-optical coherence tomography (OCT) in a single instrument. The prototype allows acquiring AO fundus images with a field of view of 4°x4° and with a frame rate of 10fps. The exposure time of a single image is 10 ms. The short exposure time results in nearly motion artifact-free high resolution images of the retina. The AO-OCT mode allows acquiring volumetric data of the retina at 200kHz A-scan rate with a transverse resolution of ~4 µm and an axial resolution of ~5 µm. OCT imaging is acquired within a field of view of 2°x2° located at the central part of the AO fundus image. Recording of OCT volume data takes 0.8 seconds. The performance of the new system is tested in healthy volunteers and patients with retinal diseases.
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Affiliation(s)
- Matthias Salas
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
| | - Wolfgang Drexler
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
| | - Xavier Levecq
- Imagine Eyes, 18 Rue Charles de Gaulle 91400 Orsay, France
| | - Barbara Lamory
- Imagine Eyes, 18 Rue Charles de Gaulle 91400 Orsay, France
| | - Markus Ritter
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
| | - Sonja Prager
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
| | - Julia Hafner
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
| | - Ursula Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
| | - Michael Pircher
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria
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15
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Morgan JIW. The fundus photo has met its match: optical coherence tomography and adaptive optics ophthalmoscopy are here to stay. Ophthalmic Physiol Opt 2016; 36:218-39. [PMID: 27112222 PMCID: PMC4963017 DOI: 10.1111/opo.12289] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 01/20/2016] [Indexed: 12/24/2022]
Abstract
PURPOSE Over the past 25 years, optical coherence tomography (OCT) and adaptive optics (AO) ophthalmoscopy have revolutionised our ability to non-invasively observe the living retina. The purpose of this review is to highlight the techniques and human clinical applications of recent advances in OCT and adaptive optics scanning laser/light ophthalmoscopy (AOSLO) ophthalmic imaging. RECENT FINDINGS Optical coherence tomography retinal and optic nerve head (ONH) imaging technology allows high resolution in the axial direction resulting in cross-sectional visualisation of retinal and ONH lamination. Complementary AO ophthalmoscopy gives high resolution in the transverse direction resulting in en face visualisation of retinal cell mosaics. Innovative detection schemes applied to OCT and AOSLO technologies (such as spectral domain OCT, OCT angiography, confocal and non-confocal AOSLO, fluorescence, and AO-OCT) have enabled high contrast between retinal and ONH structures in three dimensions and have allowed in vivo retinal imaging to approach that of histological quality. In addition, both OCT and AOSLO have shown the capability to detect retinal reflectance changes in response to visual stimuli, paving the way for future studies to investigate objective biomarkers of visual function at the cellular level. Increasingly, these imaging techniques are being applied to clinical studies of the normal and diseased visual system. SUMMARY Optical coherence tomography and AOSLO technologies are capable of elucidating the structure and function of the retina and ONH noninvasively with unprecedented resolution and contrast. The techniques have proven their worth in both basic science and clinical applications and each will continue to be utilised in future studies for many years to come.
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Affiliation(s)
- Jessica I W Morgan
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
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16
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Kumar A, Kamali T, Platzer R, Unterhuber A, Drexler W, Leitgeb RA. Anisotropic aberration correction using region of interest based digital adaptive optics in Fourier domain OCT. BIOMEDICAL OPTICS EXPRESS 2015; 6:1124-34. [PMID: 25908999 PMCID: PMC4399654 DOI: 10.1364/boe.6.001124] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 02/25/2015] [Accepted: 02/25/2015] [Indexed: 05/22/2023]
Abstract
In this paper a numerical technique is presented to compensate for anisotropic optical aberrations, which are usually present across the lateral field of view in the out of focus regions, in high resolution optical coherence tomography and microscopy (OCT/OCM) setups. The recorded enface image field at different depths in the tomogram is digitally divided into smaller sub-regions or the regions of interest (ROIs), processed individually using subaperture based digital adaptive optics (DAO), and finally stitched together to yield a final image with a uniform diffraction limited resolution across the entire field of view (FOV). Using this method, a sub-micron lateral resolution is achieved over a depth range of 218 [Formula: see text]for a nano-particle phantom sample imaged using a fiber based point scanning spectral domain (SD) OCM system with a limited depth of focus (DOF) of ~7 [Formula: see text]at a numerical aperture (NA) of 0.6. Thus, an increase in DOF by ~30x is demonstrated in this case. The application of this method is also shown in ex vivo mouse adipose tissue.
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Affiliation(s)
- Abhishek Kumar
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna,
Austria
- Christian Doppler Laboratory for Laser Development and their Application to Medicine and Biology, Waehringer Guertel 18-20 A-1090 Vienna,
Austria
| | - Tschackad Kamali
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna,
Austria
| | - René Platzer
- Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Lazarettgasse 19 A-1090 Vienna,
Austria
| | - Angelika Unterhuber
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna,
Austria
| | - Wolfgang Drexler
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna,
Austria
- Christian Doppler Laboratory for Laser Development and their Application to Medicine and Biology, Waehringer Guertel 18-20 A-1090 Vienna,
Austria
| | - Rainer A. Leitgeb
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna,
Austria
- Christian Doppler Laboratory for Laser Development and their Application to Medicine and Biology, Waehringer Guertel 18-20 A-1090 Vienna,
Austria
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17
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Felberer F, Rechenmacher M, Haindl R, Baumann B, Hitzenberger CK, Pircher M. Imaging of retinal vasculature using adaptive optics SLO/OCT. BIOMEDICAL OPTICS EXPRESS 2015; 6:1407-18. [PMID: 25909024 PMCID: PMC4399679 DOI: 10.1364/boe.6.001407] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/16/2015] [Accepted: 03/18/2015] [Indexed: 05/18/2023]
Abstract
We use our previously developed adaptive optics (AO) scanning laser ophthalmoscope (SLO)/ optical coherence tomography (OCT) instrument to investigate its capability for imaging retinal vasculature. The system records SLO and OCT images simultaneously with a pixel to pixel correspondence which allows a direct comparison between those imaging modalities. Different field of views ranging from 0.8°x0.8° up to 4°x4° are supported by the instrument. In addition a dynamic focus scheme was developed for the AO-SLO/OCT system in order to maintain the high transverse resolution throughout imaging depth. The active axial eye tracking that is implemented in the OCT channel allows time resolved measurements of the retinal vasculature in the en-face imaging plane. Vessel walls and structures that we believe correspond to individual erythrocytes could be visualized with the system.
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Affiliation(s)
- Franz Felberer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna,
Austria
- Imaging Cluster, Medical University of Vienna,
Austria
| | - Matthias Rechenmacher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna,
Austria
- Imaging Cluster, Medical University of Vienna,
Austria
| | - Richard Haindl
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna,
Austria
- Imaging Cluster, Medical University of Vienna,
Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna,
Austria
- Imaging Cluster, Medical University of Vienna,
Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna,
Austria
- Imaging Cluster, Medical University of Vienna,
Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna,
Austria
- Imaging Cluster, Medical University of Vienna,
Austria
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18
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Fechtig DJ, Grajciar B, Schmoll T, Blatter C, Werkmeister RM, Drexler W, Leitgeb RA. Line-field parallel swept source MHz OCT for structural and functional retinal imaging. BIOMEDICAL OPTICS EXPRESS 2015; 6:716-35. [PMID: 25798298 PMCID: PMC4361428 DOI: 10.1364/boe.6.000716] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/26/2015] [Accepted: 01/27/2015] [Indexed: 05/17/2023]
Abstract
We demonstrate three-dimensional structural and functional retinal imaging with line-field parallel swept source imaging (LPSI) at acquisition speeds of up to 1 MHz equivalent A-scan rate with sensitivity better than 93.5 dB at a central wavelength of 840 nm. The results demonstrate competitive sensitivity, speed, image contrast and penetration depth when compared to conventional point scanning OCT. LPSI allows high-speed retinal imaging of function and morphology with commercially available components. We further demonstrate a method that mitigates the effect of the lateral Gaussian intensity distribution across the line focus and demonstrate and discuss the feasibility of high-speed optical angiography for visualization of the retinal microcirculation.
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Affiliation(s)
- Daniel J. Fechtig
- Center for Med. Physics and Biomed. Engineering, Medical University Vienna, Waehringer Guertel 18-20, A-1090, Vienna,
Austria
- Christian Doppler Laboratory for Laser Development and their Application to Medicine and Biology, Center for Medical Physics and Biomedical Engineering, Medical University Vienna,
Austria
| | - Branislav Grajciar
- Center for Med. Physics and Biomed. Engineering, Medical University Vienna, Waehringer Guertel 18-20, A-1090, Vienna,
Austria
| | - Tilman Schmoll
- Carl Zeiss Meditec, Inc., 5160 Hacienda Drive, Dublin, CA 94568,
USA
| | - Cedric Blatter
- Center for Med. Physics and Biomed. Engineering, Medical University Vienna, Waehringer Guertel 18-20, A-1090, Vienna,
Austria
| | - Rene M. Werkmeister
- Center for Med. Physics and Biomed. Engineering, Medical University Vienna, Waehringer Guertel 18-20, A-1090, Vienna,
Austria
| | - Wolfgang Drexler
- Center for Med. Physics and Biomed. Engineering, Medical University Vienna, Waehringer Guertel 18-20, A-1090, Vienna,
Austria
- Christian Doppler Laboratory for Laser Development and their Application to Medicine and Biology, Center for Medical Physics and Biomedical Engineering, Medical University Vienna,
Austria
| | - Rainer A. Leitgeb
- Center for Med. Physics and Biomed. Engineering, Medical University Vienna, Waehringer Guertel 18-20, A-1090, Vienna,
Austria
- Christian Doppler Laboratory for Laser Development and their Application to Medicine and Biology, Center for Medical Physics and Biomedical Engineering, Medical University Vienna,
Austria
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19
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Zawadzki RJ, Capps AG, Kim DY, Panorgias A, Stevenson SB, Hamann B, Werner JS. Progress on Developing Adaptive Optics-Optical Coherence Tomography for In Vivo Retinal Imaging: Monitoring and Correction of Eye Motion Artifacts. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS : A PUBLICATION OF THE IEEE LASERS AND ELECTRO-OPTICS SOCIETY 2014; 20:7100912. [PMID: 25544826 PMCID: PMC4276343 DOI: 10.1109/jstqe.2013.2288302] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Recent progress in retinal image acquisition techniques, including optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO), combined with improved performance of adaptive optics (AO) instrumentation, has resulted in improvement in the quality of in vivo images of cellular structures in the human retina. Here, we present a short review of progress on developing AO-OCT instruments. Despite significant progress in imaging speed and resolution, eye movements present during acquisition of a retinal image with OCT introduce motion artifacts into the image, complicating analysis and registration. This effect is especially pronounced in high-resolution datasets acquired with AO-OCT instruments. Several retinal tracking systems have been introduced to correct retinal motion during data acquisition. We present a method for correcting motion artifacts in AO-OCT volume data after acquisition using simultaneously captured adaptive optics-scanning laser ophthalmoscope (AO-SLO) images. We extract transverse eye motion data from the AO-SLO images, assign a motion adjustment vector to each AO-OCT A-scan, and re-sample from the scattered data back onto a regular grid. The corrected volume data improve the accuracy of quantitative analyses of microscopic structures.
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Affiliation(s)
- Robert J. Zawadzki
- Vision Science and Advanced Retinal Imaging Laboratroy (VSRI), Department of Ophthalmology and Vision Science, and Department of Cell Biology and Human Anatomy, University of California Davis, Sacramento, CA 95817 USA
| | - Arlie G. Capps
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology and Vision Science, with the Institute for Data Analysis and Visualization (IDAV), Department of Computer Science, University of California, Davis, Davis, CA 95616 USA, and also with Physical and Life Sciences, Lawrence Livermore National Laboratory, CA 94551 USA
| | - Dae Yu Kim
- Vision Science and Advanced Retinal Imaging Laboratroy (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817 USA
| | - Athanasios Panorgias
- Vision Science and Advanced Retinal Imaging Laboratroy (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817 USA
| | | | - Bernd Hamann
- Institute for Data Analysis and Visualization (IDAV), Department of Computer Science, University of California, Davis, CA 95616–8562 USA
| | - John S. Werner
- Vision Science and Advanced Retinal Imaging Laboratroy (VSRI), Department of Ophthalmology and Vision Science, University of California Davis, Sacramento, CA 95817 USA
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20
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Felberer F, Kroisamer JS, Baumann B, Zotter S, Schmidt-Erfurth U, Hitzenberger CK, Pircher M. Adaptive optics SLO/OCT for 3D imaging of human photoreceptors in vivo. BIOMEDICAL OPTICS EXPRESS 2014; 5:439-56. [PMID: 24575339 PMCID: PMC3920875 DOI: 10.1364/boe.5.000439] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 12/30/2013] [Accepted: 01/02/2014] [Indexed: 05/18/2023]
Abstract
We present a new instrument that is capable of imaging human photoreceptors in three dimensions. To achieve high lateral resolution, the system incorporates an adaptive optics system. The high axial resolution is achieved through the implementation of optical coherence tomography (OCT). The instrument records simultaneously both, scanning laser ophthalmoscope (SLO) and OCT en-face images, with a pixel to pixel correspondence. The information provided by the SLO is used to correct for transverse eye motion in post-processing. In order to correct for axial eye motion, the instrument is equipped with a high speed axial eye tracker. In vivo images of foveal cones as well as images recorded at an eccentricity from the fovea showing cones and rods are presented.
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Affiliation(s)
- Franz Felberer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna, Austria
| | - Julia-Sophie Kroisamer
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna, Austria
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna Austria
| | - Bernhard Baumann
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna, Austria
| | - Stefan Zotter
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna, Austria
| | - Ursula Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna Austria
| | - Christoph K. Hitzenberger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna, Austria
| | - Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna, Austria
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21
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Bonora S, Zawadzki RJ. Wavefront sensorless modal deformable mirror correction in adaptive optics: optical coherence tomography. OPTICS LETTERS 2013; 38:4801-4. [PMID: 24322136 DOI: 10.1364/ol.38.004801] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a method for optimization of optical coherence tomography images using wavefront sensorless adaptive optics. The method consists of systematic adjustment of the coefficients of a subset of the orthogonal Zernike bases and application of the resulting shapes to a deformable mirror, while optimizing using image sharpness as a merit function. We demonstrate that this technique can compensate for aberrations induced by trial lenses. Measurements of the point spread function before and after compensation demonstrate near diffraction limit imaging.
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22
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Hansen A, Géneaux R, Günther A, Krüger A, Ripken T. Lowered threshold energy for femtosecond laser induced optical breakdown in a water based eye model by aberration correction with adaptive optics. BIOMEDICAL OPTICS EXPRESS 2013; 4:852-67. [PMID: 23761849 PMCID: PMC3675865 DOI: 10.1364/boe.4.000852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/05/2013] [Accepted: 04/13/2013] [Indexed: 06/02/2023]
Abstract
In femtosecond laser ophthalmic surgery tissue dissection is achieved by photodisruption based on laser induced optical breakdown. In order to minimize collateral damage to the eye laser surgery systems should be optimized towards the lowest possible energy threshold for photodisruption. However, optical aberrations of the eye and the laser system distort the irradiance distribution from an ideal profile which causes a rise in breakdown threshold energy even if great care is taken to minimize the aberrations of the system during design and alignment. In this study we used a water chamber with an achromatic focusing lens and a scattering sample as eye model and determined breakdown threshold in single pulse plasma transmission loss measurements. Due to aberrations, the precise lower limit for breakdown threshold irradiance in water is still unknown. Here we show that the threshold energy can be substantially reduced when using adaptive optics to improve the irradiance distribution by spatial beam shaping. We found that for initial aberrations with a root-mean-square wave front error of only one third of the wavelength the threshold energy can still be reduced by a factor of three if the aberrations are corrected to the diffraction limit by adaptive optics. The transmitted pulse energy is reduced by 17% at twice the threshold. Furthermore, the gas bubble motions after breakdown for pulse trains at 5 kilohertz repetition rate show a more transverse direction in the corrected case compared to the more spherical distribution without correction. Our results demonstrate how both applied and transmitted pulse energy could be reduced during ophthalmic surgery when correcting for aberrations. As a consequence, the risk of retinal damage by transmitted energy and the extent of collateral damage to the focal volume could be minimized accordingly when using adaptive optics in fs-laser surgery.
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Affiliation(s)
- Anja Hansen
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Romain Géneaux
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Axel Günther
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Alexander Krüger
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Tammo Ripken
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
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23
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Kumar A, Drexler W, Leitgeb RA. Subaperture correlation based digital adaptive optics for full field optical coherence tomography. OPTICS EXPRESS 2013; 21:10850-66. [PMID: 23669942 DOI: 10.1364/oe.21.010850] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
This paper proposes a sub-aperture correlation based numerical phase correction method for interferometric full field imaging systems provided the complex object field information can be extracted. This method corrects for the wavefront aberration at the pupil/ Fourier transform plane without the need of any adaptive optics, spatial light modulators (SLM) and additional cameras. We show that this method does not require the knowledge of any system parameters. In the simulation study, we consider a full field swept source OCT (FF SSOCT) system to show the working principle of the algorithm. Experimental results are presented for a technical and biological sample to demonstrate the proof of the principle.
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Affiliation(s)
- Abhishek Kumar
- Center of Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20 A-1090 Vienna, Austria.
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24
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Jang J, Lim J, Yu H, Choi H, Ha J, Park JH, Oh WY, Jang W, Lee S, Park Y. Complex wavefront shaping for optimal depth-selective focusing in optical coherence tomography. OPTICS EXPRESS 2013; 21:2890-902. [PMID: 23481747 DOI: 10.1364/oe.21.002890] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We report on an approach to exploit multiple light scattering by shaping the incident wavefront in optical coherence tomography (OCT). Most of the reflected signal from biological tissue consists of multiply scattered light, which is regarded as noise in OCT. A digital mirror device (DMD) is utilized to shape the incident wavefront such that the maximal energy is focused at a specific depth in a highly scattering sample using a coherence-gated reflectance signal as feedback. The proof-of-concept experiment demonstrates that this approach enhances depth-selective focusing in the presence of optical inhomogeneity, and thus extends the penetration depth in spectral domain-OCT (SD-OCT).
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Affiliation(s)
- Jaeduck Jang
- Dept. of Physics, Korea Advanced Institute of Science. and Technology, Daejeon, 305-701 South Korea
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25
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Felberer F, Kroisamer JS, Hitzenberger CK, Pircher M. Lens based adaptive optics scanning laser ophthalmoscope. OPTICS EXPRESS 2012; 20:17297-310. [PMID: 23038283 DOI: 10.1364/oe.20.017297] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
We present an alternative approach for an adaptive optics scanning laser ophthalmoscope (AO-SLO). In contrast to other commonly used AO-SLO instruments, the imaging optics consist of lenses. Images of the fovea region of 5 healthy volunteers are recorded. The system is capable to resolve human foveal cones in 3 out of 5 healthy volunteers. Additionally, we investigated the capability of the system to support larger scanning angles (up to 5°) on the retina. Finally, in order to demonstrate the performance of the instrument images of rod photoreceptors are presented.
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Affiliation(s)
- Franz Felberer
- Center for Medical Physics and Biomedical Engineering, Waehringerguertel 18-20, 1090 Vienna, Austria
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26
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Pircher M, Hitzenberger CK, Schmidt-Erfurth U. Polarization sensitive optical coherence tomography in the human eye. Prog Retin Eye Res 2011; 30:431-51. [PMID: 21729763 PMCID: PMC3205186 DOI: 10.1016/j.preteyeres.2011.06.003] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 06/16/2011] [Accepted: 06/20/2011] [Indexed: 01/06/2023]
Abstract
Optical coherence tomography (OCT) has become a well established imaging tool in ophthalmology. The unprecedented depth resolution that is provided by this technique yields valuable information on different ocular tissues ranging from the anterior to the posterior eye segment. Polarization sensitive OCT (PS-OCT) extends the concept of OCT and utilizes the information that is carried by polarized light to obtain additional information on the tissue. Several structures in the eye (e.g. cornea, retinal nerve fiber layer, retinal pigment epithelium) alter the polarization state of the light and show therefore a tissue specific contrast in PS-OCT images. First this review outlines the basic concepts of polarization changing light-tissue interactions and gives a short introduction in PS-OCT instruments for ophthalmic imaging. In a second part a variety of different applications of this technique are presented in ocular imaging that are ranging from the anterior to the posterior eye segment. Finally the benefits of the method for imaging different diseases as, e.g., age related macula degeneration (AMD) or glaucoma is demonstrated.
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Affiliation(s)
- Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerstr. 13, 1090 Vienna, Austria.
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27
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Pircher M, Götzinger E, Sattmann H, Leitgeb RA, Hitzenberger CK. In vivo investigation of human cone photoreceptors with SLO/OCT in combination with 3D motion correction on a cellular level. OPTICS EXPRESS 2010; 18:13935-44. [PMID: 20588526 PMCID: PMC2976031 DOI: 10.1364/oe.18.013935] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We present a further improvement of our SLO/OCT imaging system which enables to practically eliminate all eye motion artifacts with a correction accuracy approaching sub-cellular dimensions. Axial eye tracking is achieved by using a hardware based, high speed tracking system that consists of a rapid scanning optical delay line in the reference arm of the interferometer. A software based algorithm is employed to correct for transverse eye motion in a post-processing step. The instrument operates at a frame rate of 40 en-face fps with a field of view of approximately 1 degrees x 1 degrees. Dynamic focusing enables the recording of 3D volumes of the human retina with cellular resolution throughout the entire imaging depth. Several volumes are stitched together to increase the total field of view. Different features of the three dimensional structure of cone photoreceptors are investigated in detail and at different eccentricities from the fovea.
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Affiliation(s)
- Michael Pircher
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringerstr. 13, Vienna, Austria.
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Fingler J, Zawadzki RJ, Werner JS, Schwartz D, Fraser SE. Volumetric microvascular imaging of human retina using optical coherence tomography with a novel motion contrast technique. OPTICS EXPRESS 2009; 17:22190-200. [PMID: 19997465 PMCID: PMC2791341 DOI: 10.1364/oe.17.022190] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Phase variance-based motion contrast imaging is demonstrated using a spectral domain optical coherence tomography system for the in vivo human retina. This contrast technique spatially identifies locations of motion within the retina primarily associated with vasculature. Histogram-based noise analysis of the motion contrast images was used to reduce the motion noise created by transverse eye motion. En face summation images created from the 3D motion contrast data are presented with segmentation of selected retinal layers to provide non-invasive vascular visualization comparable to currently used invasive angiographic imaging. This motion contrast technique has demonstrated the ability to visualize resolution-limited vasculature independent of vessel orientation and flow velocity.
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Affiliation(s)
- Jeff Fingler
- California Institute of Technology, Pasadena, California 91125, USA.
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Zawadzki RJ, Choi SS, Fuller AR, Evans JW, Hamann B, Werner JS. Cellular resolution volumetric in vivo retinal imaging with adaptive optics-optical coherence tomography. OPTICS EXPRESS 2009; 17:4084-94. [PMID: 19259248 PMCID: PMC2715892 DOI: 10.1364/oe.17.004084] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Ultrahigh-resolution adaptive optics-optical coherence tomography (UHR-AO-OCT) instrumentation allowing monochromatic and chromatic aberration correction was used for volumetric in vivo retinal imaging of various retinal structures including the macula and optic nerve head (ONH). Novel visualization methods that simplify AO-OCT data viewing are presented, and include co-registration of AO-OCT volumes with fundus photography and stitching of multiple AO-OCT sub-volumes to create a large field of view (FOV) high-resolution volume. Additionally, we explored the utility of Interactive Science Publishing by linking all presented AO-OCT datasets with the OSA ISP software.
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Affiliation(s)
- Robert J Zawadzki
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology & Vision Science,University of California Davis, 4860 Y Street, Suite 2400, Sacramento, California 95817, USA.
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30
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Zawadzki RJ, Cense B, Zhang Y, Choi SS, Miller DT, Werner JS. Ultrahigh-resolution optical coherence tomography with monochromatic and chromatic aberration correction. OPTICS EXPRESS 2008; 16:8126-43. [PMID: 18545525 PMCID: PMC2519244 DOI: 10.1364/oe.16.008126] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We have developed an improved adaptive optics - optical coherence tomography (AO-OCT) system and evaluated its performance for in vivo imaging of normal and pathologic retina. The instrument provides unprecedented image quality at the retina with isotropic 3D resolution of 3.5 x 3.5 x 3.5 microm(3). Critical to the instrument's resolution is a customized achromatizing lens that corrects for the eye's longitudinal chromatic aberration and an ultra broadband light source (Delta lambda=112 nm lambda(0)= approximately 836 nm). The eye's transverse chromatic aberrations is modeled and predicted to be sufficiently small for the imaging conditions considered. The achromatizing lens was strategically placed at the light input of the AO-OCT sample arm. This location simplifies use of the achromatizing lens and allows straightforward implementation into existing OCT systems. Lateral resolution was achieved with an AO system that cascades two wavefront correctors, a large stroke bimorph deformable mirror (DM) and a micro-electromechanical system (MEMS) DM with a high number of actuators. This combination yielded diffraction-limited imaging in the eyes examined. An added benefit of the broadband light source is the reduction of speckle size in the axial dimension. Additionally, speckle contrast was reduced by averaging multiple B-scans of the same proximal patch of retina. The combination of improved micron-scale 3D resolution, and reduced speckle size and contrast were found to significantly improve visibility of microscopic structures in the retina.
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Affiliation(s)
- Robert J Zawadzki
- Vision Science and Advanced Retinal Imaging Laboratory (VSRI), Department of Ophthalmology & Vision Science, UC Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA.
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Carroll J, Choi SS, Williams DR. In vivo imaging of the photoreceptor mosaic of a rod monochromat. Vision Res 2008; 48:2564-8. [PMID: 18499214 DOI: 10.1016/j.visres.2008.04.006] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Revised: 02/03/2008] [Accepted: 04/06/2008] [Indexed: 10/22/2022]
Abstract
Complete achromatopsia (i.e., rod monochromacy) is a congenital vision disorder in which cone function is absent or severely diminished, often due to mutations in one of two components of the cone phototransduction cascade (transducin or the cyclic-nucleotide gated channel). Previous histological data concerning cone structure are conflicting; suggesting anywhere from normal numbers of foveal cones to a complete absence of foveal cones. Here, we used an adaptive optics ophthalmoscope to obtain in vivo retinal images from a rod monochromat for whom the genetic basis of the disorder consists of a homozygous mutation in the CNGB3 gene. Behavioral data from the patient were consistent with an absence of cone function. Retinal images revealed a severely disrupted photoreceptor mosaic in the fovea and parafovea, where the size and density of the visible photoreceptors resembled that of normal rods. Imaging of additional rod monochromats to characterize differences in the photoreceptor mosaic between genetically classified patients will be required to determine which, if any, might be receptive to restorative gene therapy procedures.
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Affiliation(s)
- Joseph Carroll
- Department of Ophthalmology, Medical College of Wisconsin, The Eye Institute, 925 North 87th Street, Milwaukee, WI 53226, USA.
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