Integrated scanning and ocular tomography system and method

• US 7,503,916 B2
• Filed: 05/31/2006
• Issued: 03/17/2009
• Est. Priority Date: 06/27/2002
• Status: Expired due to Fees

• Current Assignee: Amo Manufacturing Usa, Llc (Johnson & Johnson)
• Original Assignee: Advanced Medical Optics Incorporated (Johnson & Johnson)
• Inventors: Shimmick, John K.
• Primary Examiner(s): Farah; Ahmed M
• Application Number:
  US11/421,450
• Publication Number:
  US 20060206102A1
• Time in Patent Office: 1,021 Days
• Field of Search: 606 3- 12, 607/88, 607/89, 607/92, 607/94, 128/898
• US Class Current: 606/5
• CPC Class Codes: A61B 2090/061 for measuring dimensions, e.g. length
• CPC Class Codes: A61B 3/1005 for measuring distances inside the eye, e.g. thickness of the cornea A61B3/11 takes precedence
• CPC Class Codes: A61F 2009/00842 Permanent Structural Change [PSC] in index of refraction; Limit between ablation and plasma ignition
• CPC Class Codes: A61F 2009/00851 Optical coherence topography [OCT]
• CPC Class Codes: A61F 2009/00853 Laser thermal keratoplasty or radial keratotomy
• CPC Class Codes: A61F 2009/00872 Cornea
• CPC Class Codes: A61F 2009/0088 based on wavefront
• CPC Class Codes: A61F 2009/00882 based on topography
• CPC Class Codes: A61F 2009/00897 Scanning mechanisms or algorithms
• CPC Class Codes: A61F 9/008 using laser
• CPC Class Codes: A61F 9/00804 Refractive treatments
• CPC Class Codes: A61F 9/00812 Inlays; Onlays; Intraocular lenses [IOL]
• CPC Class Codes: G01B 2290/25 Fabry-Perot in interferometer, e.g. etalon, cavity
• CPC Class Codes: G01B 2290/70 Using polarization in the interferometer
• CPC Class Codes: G01B 9/02002 using two or more frequencies
• CPC Class Codes: G01B 9/02007 Two or more frequencies or sources used for interferometric measurement using only beat G01B9/02003
• CPC Class Codes: G01B 9/02044 Imaging in the frequency domain, e.g. by using a spectrometer
• CPC Class Codes: G01B 9/0209 Low-coherence interferometers
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence

Abstract

Systems and methods of the present invention measure at least one reflecting surface of an object disposed along an optical path. In some embodiments a measured optical interference signal for each of at least three wavelengths of reflected light may be used to determine a modulation of frequency components of a Fourier series. Frequency components of a Fourier series may be transformed to spatial components that describe intensities and positions of light reflected along an optical path.

Systems and methods of the present invention permit rapid measuring and may monitor corneal thickness during surgery. The invention may do so by integrating an ablation device and a measurement apparatus into a single system. An integrated scanning and monitoring system may include an ablative light source producing an ablative beam and a measurement light source producing a measurement beam.

Claims

1. A method of treating a tissue, the method comprising:

directing an ablative beam for ablating the tissue via a scanning device to the tissue;

directing a measurement beam for measuring a profile of the tissue via the scanning device to the tissue, the measurement beam comprising at least three wavelengths, wherein a path of the ablative beam and a path of the measurement beam are substantially concentric as directed onto the tissue and wherein the measurement light beam comprising the at least three wavelengths is reflected from the tissue;

measuring a signal for each of the at least three wavelengths reflected from the tissue; and

combining the measured signals to determine a thickness profile of the tissue; and

ablating the tissue in response to the thickness profile.

2. The method of claim 1 wherein the path of the ablative beam and the path of the measurement beam are substantially coaxial as directed onto the tissue.

3. The method of claim 1 further comprising measuring of the tissue intermittently at time intervals between instances of ablation.

4. The method of claim 1 wherein the measurement beam is directed to the tissue via the scanning device for measuring a thickness of the tissue.

5. An apparatus for ablating tissue, the apparatus comprising:

an ablative light source producing an ablative light beam;

a measurement light source producing a measurement light beam comprising at least three wavelengths of light;

a detector configured to measure a signal for each of the at least three wavelengths of light;

a scanner receiving the ablative beam from the ablative light source and the measurement beam from the measurement light source, the scanner including optical elements for directing the ablative beam and the measurement beam to locations across the tissue so as to ablate the tissue with the ablative beam and measure a thickness profile of the tissue with the measurement beam, a path of the ablative beam and a path of the measurement beam being substantially concentric at the tissue; and

a processor comprising a tangible medium configured to combine the measured signals to determine the thickness profile of the tissue and ablate the tissue in response to the thickness profile.

6. The apparatus of claim 5 wherein the path of the ablative beam and the path of the measurement beam are substantially coaxial as directed onto the tissue.

7. The apparatus of claim 5 further comprising a processor electrically connected with the ablative light source and the measurement light source, the processor controlling of the ablative light beam and the measurement light beam.