University of Utah Research Foundation

Image Technologies Corporation

Longevity Link Corporation

Werner Gellermann

Mohsen Sharifzadeh

Paul S Bernstein

Fritz Luty

Robert W McClane

Yihong Yang

Igor V Ermakov

Robert McClane

Nikita B Katz

A method, system, and computer program product are disclosed for diagnosing a condition of an eye such as macular degeneration and/or cataracts. The system may include an optical system, which may project light at an eye and record lipofuscin fluorescence from a retina of the eye to form an image of the retina. A computing device may process the image to apply one or more image acceptance criteria and/or one or more image clarity criteria. If the image fails to meet the one or more image acceptance criteria, the image may be re-taken. Based on the level of conformance of the image to the one or more image clarity criteria, the system may indicate that the macular pigment level cannot be provided with confidence, indicate that the eye likely has one or more cataracts, and/or calculate and provide the macular pigment content based on a correction factor, if needed.

Autofluorescence imaging of macular pigment: image quality criteria and corrections

Methods and apparatus are disclosed which facilitate the rapid, noninvasive and quantitative measurement of the concentration of flavonoid compounds, as well as their isomers and metabolites, in biological tissue such as human skin. Low-intensity, visible-light illumination of intact tissue provides for high spatial resolution, and allows for precise quantification of the flavonoid levels in the tissue. The preferred embodiments make use of a previously unknown, low-oscillator strength, optical absorption transition of flavonoids. This makes it possible to optically excite flavonoids in living human tissue outside the absorption range of other, potentially confounding skin chromophores. A system constructed in accordance with the invention includes a source of light for illuminating a localized region of tissue with light that overlaps the absorption bands of a flavonoid compound; a device for detecting the fluorescence emitted by the flavonoid compound resulting from the illumination; and a processor for determining the concentration level of the flavonoid compound based upon the detected fluorescence.

Noninvasive measurement of flavonoid compounds in biological tissue

Macular pigments are measured by spectrally selective lipofuscin detection. Light from a light source that emits light at a selected range of wavelengths that overlap the absorption band of macular carotenoids is directed onto macular tissue of an eye for which macular pigment levels are to be measured. Emitted light is then collected from the macular tissue. The collected light is filtered so that the collected light includes lipofuscin emission from the macular tissue at an excitation wavelength that lies outside the macular pigment absorption range and outside the excitation range of interfering fluorophores. The collected light is quantified at each of a plurality of locations in the macular tissue and the macular pigment levels in the macular tissue are determined from the differing lipofuscin emission intensities in the macula and peripheral retina.

Imaging of macular pigment distributions

A method for optical detection of lipofuscin concentrations in the retina is described. A subject's eye is exposed to a light source. Light emitted from the subject's eye is detected. Levels of lipofuscin are determined from the emitted light. A system for optical detection of lipofuscin in the retina is described. The system includes a light source to generate light. The system includes an optical detector in optical communication with the light source. The optical detector is configured to detect light emitted from a subject's eye. A computing device in electronic communication with the optical detector is included in the system to determine levels of lipofuscin from the emitted light.

Systems and methods for optical detection of lipofuscin concentrations in a subject's eye

A method and apparatus are provided for Raman imaging of carotenoids and related chemical substances in biological tissue, such as macular pigments. The method and apparatus utilize the technique of resonance Raman spectroscopy to produce an image of the levels of carotenoids and similar substances in tissue. In this technique, light is directed upon the area of tissue which is of interest such as the retina of an eye. A small fraction of the scattered light is scattered inelastically, producing a carotenoid Raman signal which is at a different frequency than the incident light. The Raman signal is collected, filtered, and analyzed to determine the spatial position and intensity of the Raman signals in the inelastically scattered light. An image of the Raman signals is then produced on an output device, with the image representing the spatial distribution and concentration level of carotenoids in the tissue.

Method and apparatus for Raman imaging of macular pigments

A method and apparatus are provided for the determination of levels of carotenoids and similar chemical compounds in biological tissue such as living skin. The method and apparatus provide a noninvasive, rapid, accurate, and safe determination of carotenoid levels which in turn can provide diagnostic information regarding cancer risk, or can be a marker for conditions where carotenoids or other antioxidant compounds may provide diagnostic information. Such early diagnostic information allows for the possibility of preventative intervention. The method and apparatus utilize the technique of resonance Raman spectroscopy to measure the levels of carotenoids and similar substances in tissue. In this technique, laser light is directed upon the area of tissue which is of interest. A small fraction of the scattered light is scattered inelastically, producing the carotenoid Raman signal which is at a different frequency than the incident laser light, and the Raman signal is collected, filtered, and measured. The resulting Raman signal can be analyzed such that the background fluorescence signal is subtracted and the results displayed and compared with known calibration standards.

Method and apparatus for noninvasive measurement of carotenoids and related chemical substances in biological tissue

The present invention is directed to a new and useful method and apparatus for use in determining the levels of macular pigments in the tissue of live subjects. Specifically, the method and apparatus of the present invention provide a non-invasive, rapid, and objective determination of the macular carotenoid levels, and in turn, offer valuable diagnostic information applicable to large populations. The present invention measures the levels of macular carotenoid pigments, as well as other retinal materials. Monochromatic laser light is projected onto a retina, preferably in the macular area. A very sensitive detection system then detects light scattered from the retina. The majority of the light is scattered elastically at the same wavelength of the laser in a manner known as Rayleigh scattering. A very small fraction of laser light is scattered inclastically at a wavelength different from that of the laser in a manner known as Raman scattering. The Raman scattered light is selected and then routed to a detection system, wherein the results are calibrated against actual standards for the particular retinal material being tested.

Method and system for measurement of macular carotenoid levels

Stable color centers capable of laser emission in the near infrared region of the optical spectrum are provided in alkali halide host crystals containing monovalent heavy metal cation impurities such as thallium, gallium, indium, silver and copper. The laser active color centers are formed by exposing the crystal to ionizing radiation followed by irradiation with light having a wavelength absorbed by the F centers. The resulting material is capable of stable, broadly tunable laser operation with high power output in the near infrared region. Oscillation on a single mode can be easily obtained.

Color centers for tunable lasers in the near infrared region

Vibrational emission from molecular defects in ionic crystals can be realized by dilute diatomic molecular defects such as, e.g., CN.sup.- molecules in alkali halide crystals. After association of F-centers to the CN.sup.- molecules, forming a new F-center/molecular defect pair, the emission can be pumped by optical F-center excitation through electronic-vibrational coupling. Using this coupling mechanism, laser action in the near infrared wavelength region is obtained between vibrational energy levels of the molecules while pumping the F-center/molecule defect in the visible wavelength range. The laser crystals are prepared by additively coloring a CN.sup.- doped alkali halide crystal and exposing the colored crystal to light having a wavelength capable of being absorbed by the electronic F-center/molecule defect transition.

Growing community of inventors

Salt Lake City, UT, United States of America

Werner Gellermann