1. Articles in category: Ophthalmology

    11233-11253 of 11253 « 1 2 ... 466 467 468 469
    1. Method and apparatus for improving vision and the resolution of retinal images

      A method of and apparatus for improving vision and the resolution of retinal images is described in which a point source produced on the retina of a living eye by a laser beam is reflected from the retina and received at a lenslet array of a Hartmann-Shack wavefront sensor such that each of the lenslets in the lenslet array forms an aerial image of the retinal point source on a CCD camera located adjacent to the lenslet array. The output signal from the CCD camera is acquired by a computer which processes the signal and produces a correction signal which ...

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    2. Process and arrangement for examining a section of the eye

      Systems, methods, and apparatus are provided for deriving the relative position of an eye by tracking a boundary of the eye such as the limbus (i.e., the interface between the white sclera and the colored iris). A technique for tracking the position of the eye of patient comprises directing light to an annular region of the eye between the sclera and the iris and receiving reflected light from that region. The intensity of the reflected light is then measured to determine a relative position of the eye. In some embodiments, the measured region is scanned around the boundary. In ...
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    3. Kinetic acoustic ocular examination apparatus and method

      Soft tissue examination apparatus and method employ an ultrasonic transducer system for generating a series of ultrasound pulses, at least one of which is of sufficiently high intensity to induce physical displacement of the soft tissue. The transducer receives a series of ultrasonic echo pulses and responsively generates a series of data signals indicative of such tissue displacement. A data processor receives the data signals and determines the magnitude of the displacement. In such a manner, the present invention assists in the evaluation and/or diagnosis of biological tissue. Preferably, the apparatus and method of this invention is employed to ...
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    4. Corneal Topography: A review, new ANSI standards and problems to solve

      Corneal Topography: A review, new ANSI standards and problems to solve
      This review of corneal topography has three sections: 1. a brief introduction to how corneal topography instruments work. A quantitative comparison of the relative accuracy of slope based and position based instruments is presented. 2. a summary of and commentary on the newly issued ANSI standards for corneal topography. 3. an examination of problems still facing corneal topography
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    5. Optical coherence tomography assisted surgical apparatus

      Ophthalmologic surgical microscope which is combined internally with an optical coherence tomography ("OCT") apparatus wherein auto-focusing is provided by driving a motorized internal focusing lens of the ophthalmologic surgical microscope with a signal output from the OCT apparatus. An embodiment of the inventive ophthalmologic surgical microscope includes: (a) an optical coherence tomography ("OCT") apparatus; (b) a beamcombiner for internally coupling output from the OCT apparatus into the ophthalmologic surgical microscope; and (c) a motor for moving an internal focusing lens of the ophthalmologic surgical microscope in response to a signal from the OCT apparatus, whereby the ophthalmologic surgical microscope is ...
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    6. Retinal nerve fiber layer thickness predicts brain atrophy in MS patients

      The thickness of the retinal nerve fiber layer (RNFL), as measured by optical coherence tomography (OCT), correlates with brain atrophy in patients with multiple sclerosis (MS), according to a new report. The thickness of the retinal nerve fiber layer (RNFL), as measured by optical coherence tomography (OCT), correlates with brain atrophy in patients with multiple sclerosis (MS), according to a report in the October 16th issue of Neurology. "This is a promising, inexpensive tool that images CNS nerve fibers," Dr. Peter A. Calabresi from Johns Hopkins School of Medicine, Baltimore, Maryland told Reuters Health. "It may be very useful to ...
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    7. Method and apparatus for simultaneously measuring the length and refractive error of an eye

      Embodiments of the present invention are method and apparatus for simultaneously measuring the length and refractive error of an eye, preferably in a non-contact mode. In particular, an embodiment of the present invention is an apparatus which measures length and refractive error of an eye which includes: (a) a source of short coherence radiation which couples radiation into a Michelson interferometer, the arms of the Michelson interferometer having a predetermined optical pathlength difference; (b) an injector which couples radiation output from the interferometer into the eye; and (c) a relay system which couples radiation output from the eye to a ...
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    8. Optical mapping apparatus with adjustable depth resolution

      Optical mapping apparatus with adjustable depth resolution is provided. The optical mapping apparatus can display transversal images in an object, particularly the eye. The apparatus can deliver two or more images with different depth resolutions, or a combination of these images, or only one image with adjustable depth resolution. There is also provided optical mapping apparatus with adjustable depth resolution, where OCT images are corrected for the curvature at the back of the eye lens.
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    9. Method of selecting an intraocular lens to be implanted into an eye

      A method of preoperatively selecting an intraocular lens to be implanted into an eye to postoperatively render the eye emmetropic or ametropic with a desired postoperative refraction comprises determining the location of the lens haptic plane of the eye, the corneal power of the eye and the axial length of the eye, choosing the desired postoperative refraction and assuming a lens to be implanted, the lens having a known power and geometry, including an offset between the lens haptic plane and an anterior vertex of the lens as if it was in its implanted state. With these parameters and refractive ...
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    10. Method and apparatus for improving vision and the resolution of retinal images

      A method of and apparatus for improving vision and the resolution of retinal images is described in which a point source produced on the retina of a living eye by a laser beam is reflected from the retina and received at a lenslet array of a Hartmann-Shack wavefront sensor such that each of the lenslets in the lenslet array forms an aerial image of the retinal point source on a CCD camera located adjacent to the lenslet array. The output signal from the CCD camera is acquired by a computer which processes the signal and produces a correction signal which ...

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    11. Method and apparatus for improving vision and the resolution of retinal images

      A method of and apparatus for improving vision and the resolution of retinal images is described in which a point source produced on the retina of a living eye by a laser beam is reflected from the retina and received at a lenslet array of a Hartmann-Shack wavefront sensor such that each of the lenslets in the lenslet array forms an aerial image of the retinal point source on a CCD camera located adjacent to the lenslet array. The output signal from the CCD camera is acquired by a computer which processes the signal and produces a correction signal which ...

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    12. Gaze tracking using optical coherence tomography

      Apparatus for gaze tracking an eye utilizing short coherence length interferometry, also known as optical coherence tomography ("OCT"). An embodiment of the present invention is an apparatus for gaze tracking an eye which includes: (a) an optical coherence tomography (OCT) apparatus; (b) a scanning apparatus for scanning across a predetermined portion of the eye with optical output from the OCT apparatus; (c) an analysis apparatus for analyzing detection signals output from the OCT apparatus to determine a location of a feature of the eye; (d) an illumination apparatus for producing a reflection of radiation from a cornea of the eye ...
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    13. Optical coherence tomography of the eye (Thesis)

      Optical coherence tomography of the eye (Thesis)
      Optical Coherence Tomography (OCT) is a new technique for high-resolution, cross-sectional imaging of tissue in which the time-of-flight delay of light reflected from internal tissue structures is resolved with high precision using interferometer. Tomographic images are obtain which are analogous to those provided by ultrasound except that image contrast relies on differences in optical rather than acoustic properties of tissue. The use of light rather than sound enable higher resolution (10 um) and non-contact imaging. A clinically viable high-sensitivity, fiber-optic based OCT instrument has been constructed based on engineering principles derived from optical communication theory. Computer algorithms have also been ...
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    14. Method and apparatus for optical coherence tomographic fundus imaging without vignetting

      Apparatus for illuminating the fundus of an eye with a scanned sample beam of radiation, the scanned sample beam emerging from a beam scanner which is exposed to a sample beam, which apparatus is for use in optical coherence tomography. An embodiment of the apparatus includes: (a) scanner lens and a beamsplitter for transferring radiation from the scanned sample beam, including chief rays of the sample beam which emerge from a point of final deflection of the beam scanner, and (b) a lens for focusing the transferred radiation so that the scanned sample beam is focused onto the fundus by ...
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    15. Fundus illumination apparatus formed from three, separated radiation path systems

      Apparatus for illuminating the fundus of an eye with a scanned sample beam of radiation. An embodiment of the present invention is an optical system which includes three, separated radiation path systems--a tilted illumination path system, a decentered observation path system, and an optical path system--which are combined by a beamsplitter into an ocular lens. In accordance with the present invention, an illuminating path provided by the illumination path system and an optical beam path provided by the optical beam path system are obliquely oriented with respect to the optical axis of the ocular lens.
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    16. Optical coherence tomography assisted ophthalmologic surgical microscope

      Ophthalmologic surgical microscope which is combined internally with an optical coherence tomography ("OCT") apparatus wherein auto-focusing is provided by driving a motorized internal focusing lens of the ophthalmologic surgical microscope with a signal output from the OCT apparatus. An embodiment of the inventive ophthalmologic surgical microscope includes: (a) an optical coherence tomography ("OCT") apparatus; (b) a beamcombiner for internally coupling output from the OCT apparatus into the ophthalmologic surgical microscope; and (c) a motor for moving an internal focusing lens of the ophthalmologic surgical microscope in response to a signal from the OCT apparatus, whereby the ophthalmologic surgical microscope is ...
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    17. Optical coherence tomography corneal mapping apparatus

      Optical coherence tomography ("OCT") corneal mapping apparatus includes an OCT apparatus having a rotating helical mirror for altering a reference beam path in the OCT apparatus; a raster scanner for raster scanning sampling optical output from the OCT apparatus; a curved mirror for transferring the sampling optical output from the raster scanner to an eye and for transferring sampling optical output reflected from the eye back to the OCT apparatus through the raster scanner; and an analyzer, coupled to the raster scanner, the rotating helical mirror, and reference and sampling interaction output from the OCT apparatus. The analyzer causes the ...
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    18. Measurement of lens characteristics

      Method and apparatus for measuring the following lens characteristics: (a) curvature of the front and back surfaces of the lens; (b) physical thickness; and (c) index of refraction of the lens to determine the front vertex power, back vertex power; and the lens material. In particular, an embodiment of one aspect of the present invention for measuring the index of refraction of the glass includes: (a) a source of a substantially spatially coherent beam of radiation and having a short temporal coherence length; (b) a beamsplitter to provide a sample beam and a reference beam in response to the beam ...
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    19. In vivo retinal imaging by optical coherence tomography

      In vivo retinal imaging by optical coherence tomography
      We describe what are to our knowledge the first in vivo measurements of human retinal structure with optical coherence tomography. These images represent the highest depth resolution in vivo retinal images to date. The tomographic system, image-processing techniques, and examples of high-resolution tomographs and their clinical relevance are discussed
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    20. Optical Coherence Tomography

      A technique called optical coherence tomography (OCT) has been developed for noninvasive cross-sectional imaging in biological systems. OCT uses low-coherence interferometry to produce a two-dimensional image of optical scattering from internal tissue microstructures in a way that is analogous to ultrasonic pulse-echo imaging. OCT has longitudinal and lateral spatial resolutions of a few micrometers and can detect reflected signals as small as approximately 10(-10) of the incident optical power. Tomographic imaging is demonstrated in vitro in the peripapillary area of the retina and in the coronary artery, two clinically relevant examples that are representative of transparent and turbid media ...
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    11233-11253 of 11253 « 1 2 ... 466 467 468 469
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  3. Organizations in the News

    1. (3 articles) Harvard University
    2. (3 articles) Massachusetts Eye and Ear Infirmary
    3. (2 articles) Johns Hopkins University
    4. (2 articles) UCLA
    5. (2 articles) University of Washington
    6. (2 articles) Centre Hospitalier Intercommunal de Créteil
    7. (2 articles) Queen's University Belfast
    8. (2 articles) University of Miami
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    11. (1 articles) Peking University
    12. (1 articles) L V Prasad Eye Institute
  4. People in the News

    1. (2 articles) Eric H. Souied
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    3. (1 articles) Michael W. Jenkins
    4. (1 articles) Elias Reichel
    5. (1 articles) Jay S. Duker
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    8. (1 articles) James G. Fujimoto
    9. (1 articles) University of Leipzig
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  5. OCT Companies in the News

    1. (10 articles) Topcon Medical Systems
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    3. (3 articles) Optovue
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    6. (1 articles) Optos