US20080249512A1 - Surgical visual feedback and eye fixation method and apparatus - Google Patents

Surgical visual feedback and eye fixation method and apparatus Download PDF

Info

Publication number
US20080249512A1
US20080249512A1 US11/354,718 US35471806A US2008249512A1 US 20080249512 A1 US20080249512 A1 US 20080249512A1 US 35471806 A US35471806 A US 35471806A US 2008249512 A1 US2008249512 A1 US 2008249512A1
Authority
US
United States
Prior art keywords
eye
information
patient
laser
fixation target
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US11/354,718
Inventor
Paul Phillip Van Saarloos
Jon Dishler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US11/354,718 priority Critical patent/US20080249512A1/en
Publication of US20080249512A1 publication Critical patent/US20080249512A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F9/00802Methods or devices for eye surgery using laser for photoablation
    • A61F9/00804Refractive treatments
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F2009/00861Methods or devices for eye surgery using laser adapted for treatment at a particular location
    • A61F2009/00872Cornea
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/008Methods or devices for eye surgery using laser
    • A61F2009/00878Planning
    • A61F2009/00882Planning based on topography
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F9/00Methods or devices for treatment of the eyes; Devices for putting-in contact lenses; Devices to correct squinting; Apparatus to guide the blind; Protective devices for the eyes, carried on the body or in the hand
    • A61F9/007Methods or devices for eye surgery
    • A61F9/013Instruments for compensation of ocular refraction ; Instruments for use in cornea removal, for reshaping or performing incisions in the cornea

Definitions

  • the present invention relates, in different aspects, to eye fixation and to the provision of visual feedback to a surgeon, during the delivery of medical laser procedures, particularly in the fields of ophthalmic surgical procedures, such as Photorefractive Keratectomy (PRK) and Laser-in-situ Keratomileusis (LASIK), or any laser based refractive correction.
  • PRK Photorefractive Keratectomy
  • LASIK Laser-in-situ Keratomileusis
  • the invention will be described with reference to these applications, though it is to be understood that other applications are envisaged.
  • Refractive errors are usually assessed when the patient is seated in an upright position using structured shapes or symbols, such as letters of the alphabet.
  • refractive surgery is usually performed with the patient reclining in an operating chair. It has been found that, when a patient lies recumbent, the ocular globe is liable to rotate, altering the position of the axis of astigmatism between 7° and 16° in 25% of cases (Smith, Talamo, Assil & Petashnick, “Comparison of Astigmatic Axis in the Seated and Supine Positions”, J. of Refractive & Corneal Surgery 10(6), 615 (1994)). This occurs for two reasons: i) the removal of the reference horizon, and ii) the change from binocular to monocular vision.
  • Focussing on a point of light (the flashing LED), instead of the linear horizon, does not provide a proper point of horizontal or vertical reference.
  • the globe is therefore liable to rotate fractionally, possibly resulting in misalignment of the treatment of the eye's axis of astigmatism.
  • the potential end result is under-treatment of the original astigmatic error or inducement of astigmatism at another axis.
  • U.S. Pat. No. 5,549,597 describes a method for determining the axis of astigmatism of a patient undergoing refractive surgery, so as to provide real-time alignment information for the surgical procedure.
  • the patient is required to focus on a target such as three sets of three lines of variable line spacing, each set corresponding to a different visual acuity, and then to focus on the best resolved set of lines and rotate the target until the finest line is seen most clearly.
  • This method of determining the axis of astigmatism and aligning the surgical laser is not ideal.
  • the patient is forced to make subjective comparisons at a highly stressful time.
  • the globe may still rotate after the alignment has been performed, and prior to surgery.
  • U.S. Pat. No. 5,442,412 discloses a patient responsive eye fixation target for use in ophthalmic procedures in which respective light sources produce a ring of light and a dot of light centred on the same optical axis, but respectively closer to and further from the eye.
  • the dot is altered in appearance, eg. by flashing or colour changes, to alert the patient that his or her eye is no longer aligned with the dot and ring.
  • the apparatus used by the surgeon to view and assess the extent of fixation and the alignment of the laser beam.
  • the surgeon views this display when looking down the surgical microscope.
  • Current technology provides a display including a graticule or crosshair.
  • a He—Ne beam is sometimes provided for aiming the surgical beam.
  • U.S. Pat. No. 4,870,964 provides a head-up display for use with an operating microscope during phaco-emulsification procedures.
  • This apparatus allows the operating surgeon to view information about the status of the patient, the eye and operating equipment, such as vacuum pressure, without removing their gaze from the operating field. It does so by projecting light onto the operating field of the eye and conditioning the reflections from the cornea so that interpretable images may be viewed by the surgeon as they look down the microscope.
  • U.S. Pat. No. 5,135,299 describes a similar operating microscope featuring a head-up display, produced by reflecting operational information from the scleral portion of the eye.
  • the arrangement reduces the angular rotation of the ocular globe to facilitate alignment of an instrument with the axis of astigmatism.
  • a method for limiting the rotation of the ocular globe of an eye to facilitate alignment of an instrument with the axis of astigmatism of the eye includes providing fixation target means in the field of view of the eye so that the eye may fixate on the target.
  • the fixation target means includes or consists of at least one elongate component having a fixed orientation.
  • the method includes providing the fixation target means by way of light emitting means.
  • the light emitting means is strobed.
  • the present invention also provides, in its first aspect, a fixation apparatus that limits rotation of the ocular globe of an eye, to facilitate alignment of an instrument with the axis of astigmatism of the eye.
  • the apparatus includes fixation target means for locating in the field of view of the eye so that the eye may fixate on the target.
  • the fixation target means includes or consists of at least one elongate component having a fixed orientation.
  • said fixation target means includes or consists of at least two intersecting substantially mutually perpendicular elongate components.
  • the fixation target means may consist substantially of a cross, and/or it may include more than two elongate components arranged as a grid.
  • the fixation target means preferably has a fixed orientation.
  • the fixation target means may be a light emitting means. Moreover, the or each elongate component may be defined by the light emitting means.
  • the light emitting means includes a plurality of light emitting diodes (LEDs) arranged in a respective linear array to define the or each elongate component.
  • LEDs light emitting diodes
  • the apparatus includes a printed circuit board (PCB) on which the LEDs are mounted.
  • PCB printed circuit board
  • the apparatus is controllable to strobe the light emitting means.
  • the apparatus may include a pulsable power supply to strobe the light emitting means.
  • the invention extends to laser surgery apparatus incorporating patent observable fixation apparatus as described above.
  • a method for supplying visual feedback to an operator during refractive surgery of an eye of a patient including:
  • the method includes updating the information display.
  • step 3 includes generating the information display with a controller means.
  • the controller means is a computer.
  • the method includes transmitting the information display to a display means and displaying the information display on the display means.
  • the display means may be miniature TV or LCD screen or a plurality of LEDs.
  • step 1) includes the alignment facilitating method according to the first aspect of the invention.
  • the viewing means includes left and right optics means, and the target is located between the left and right optics means.
  • the viewing means is a surgical microscope.
  • the invention extends to a method of performing refractive surgery on an eye of a patient, wherein visual feedback is supplied in accordance with the method of the second aspect of the invention.
  • the refractive surgery may eg. be PRK or LASIK, thermal keratoplasty intrastromal ablation or any other surgical method that alters the refraction of the eye.
  • the method may be performed with any laser suitable for use in surgery that involves altering the refractive properties of the eye, e.g. an ultraviolet ablation laser, a Holmium laser, or an Erbium laser at 3 microns.
  • any laser suitable for use in surgery that involves altering the refractive properties of the eye, e.g. an ultraviolet ablation laser, a Holmium laser, or an Erbium laser at 3 microns.
  • step 4) includes viewing said information by means of a beam splitter or plate of glass.
  • the invention also provides an apparatus for supplying visual feedback to an operator during refractive surgery of an eye.
  • the apparatus includes fixation target means for the eye to fixate upon, and viewing means for viewing the eye while it is fixated upon the fixation target means.
  • Controller means is provided for generating an information display, and screen means displays the said information display, for viewing by the viewing means, whereby the eye and the information display may be viewed simultaneously by the operator.
  • the apparatus includes display means for displaying the information display.
  • the apparatus may be provided in combination with a surgical laser and thereby comprise laser surgery apparatus.
  • the laser may be any laser suitable for use in surgery that involves altering the refractive properties of the eye, such as a ultraviolet ablation laser, a Holmium laser, an Erbium laser at 3 microns or any other appropriate laser source.
  • the target means is a fixation apparatus according to the first aspect of the invention.
  • the display means and/or screen means may be viewed by means of a beam splitter or plate of glass.
  • the display means is a miniature TV or LCD screen or a plurality of LEDs.
  • the viewing means is a surgical microscope.
  • the controller means is a computer.
  • the viewing means includes left and right optics, and the target is located between the left and right optics.
  • the information may include an alert signal indicating misalignment of the patient's eye, eg. due to straying from fixation upon the fixation target means.
  • the information may pertain to one or more of: the status of the patient, the surgery or the equipment, the position of the eye or where an eye tracker is aiming the laser.
  • the information may include one or more of the following elements of operational information: type of treatment, number of laser pulses required to finish, operation time remaining, patient identification and which eye is being treated, keratometry information, refraction information, and/or topographical information.
  • the information may include microkeratome status information, such as suction and blade speed readings.
  • FIG. 1 is a schematic view of an eye fixation apparatus according to a preferred embodiment of the first aspect of the present invention
  • FIG. 2 is a fragmentary view illustrating a suitable location for the eye fixation target.
  • FIG. 3 is a diagram of the layout of the principal components of an arrangement for supplying visual feedback to an ophthalmic surgeon during refractive laser eye surgery procedures, according to a preferred embodiment of the second aspect of the present invention, but preferably incorporating the embodiment of FIGS. 1 and 2 .
  • the apparatus 10 includes a fixation target in the form of a cross 12 formed by surface mounted light emitting diodes, LEDs 14 , arranged in two linear arrays to define intersecting elongate components or axes 16 , 18 perpendicular to one another.
  • the LEDs are fixed to a printed circuit board (PCB) 13 , in turn arranged on an elongate lipped substrate 15 .
  • Substrate 15 is positioned on the front of the surgical microscope 28 , symmetrically between the adjacent stereo oculars 40 , 42 , so as to be clearly observable by the patient.
  • cross 12 may be located elsewhere within the surgical laser, and projected to optically appear as if it is placed between the oculars of the microscope.
  • Substrate 15 is fixed in position on the microscope so that cross 12 has a fixed orientation. “Vertical” axis 16 of the cross 12 of LEDs 14 is longer than “horizontal” axis 18 , by providing several more LEDs 14 in axis 16 than axis 18 . By “vertical” is meant the axis that extends normal to the lines joining the oculars.
  • the LEDs 14 may alternatively be positioned to form any other pattern of elongate or linear elements, such as a line or a grid.
  • the cruciform arrangement of LEDs 14 allows the patient to better judge horizontal and vertical directions, so that the ocular globe(s) of the patient does not rotate and the axis of astigmatism is naturally aligned.
  • a suitable control circuit 20 for strobing LEDs 14 in a pre-selected, perhaps adjustable, sequence.
  • the LEDs may, for example, flash in unison or in a more complex pattern.
  • LEDs 14 may be of varying colours to facilitate patient concentration and gaze control. In use, the patient is required to fixate his or her gaze on the flashing cross 12 , thereby preventing angular rotation of the ocular globe and misalignment of the treatment eye's axis of astigmatism.
  • a preferred flash rate is about 1.5 Hz with a duty cycle of about 50%.
  • the duty cycle may be adjustable, for example to allow more light during LASIK and less light during PRK.
  • FIG. 3 is a diagram of an apparatus 22 for supplying visual feedback to an ophthalmic surgeon during refractive laser eye surgery procedures being performed on an eye 24 .
  • This apparatus is an embodiment of the second aspect of the invention.
  • the apparatus 22 includes a surgical microscope 28 ′, a fixation target 26 , which is preferably a flashing cross 12 ′ as in FIGS. 1 and 2 , on microscope 28 ′, a head-up display 30 to give the surgeon feedback regarding patient fixation, the operating conditions and other pertinent information, and an imaging device in the form of a miniaturised TV or LCD screen 32 supplied within the laser delivery head (not shown).
  • the head-up display 30 may be produced by projecting lights onto a surface, as is known in the art, and may be displayed on screen 32 .
  • the imaging device may alternatively comprise a combination of light emitting diodes.
  • the apparatus 22 further includes a controller in the form of computer 34 and communications link 36 between computer 34 and screen 32 .
  • Computer 34 generates the information content (comprising information pertinent to the operation being carried out) of the head-up display 30 , and transmits this content via link 36 to screen 32 to display.
  • This content could include a pulse countdown, operation time remaining, an alert signal indicating misalignment of the patient's eye, a cross 31 indicating where the laser is currently aimed, patient information such as name or ID, treatment zone information, topographical information and any other information that the surgeon may deem useful.
  • the apparatus 22 also includes a beamsplitter 38 , by which the head-up display 30 is viewed.
  • the beamsplitter 38 forms a part of the optics of the laser (not shown), for relaying this information towards oculars 40 ′, 42 ′ of the microscope 28 ′, so that the operator may see the information when he or she looks down the microscope 28 ′.
  • a suitable fixation target 26 such as a fixation cross 12 ′ as described above
  • the surgeon is able to view the patient's eye 24 ( 51 ) and the head-up display 30 ( 52 ) through the surgical microscope 28 ′.

Landscapes

  • Health & Medical Sciences (AREA)
  • Ophthalmology & Optometry (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • Optics & Photonics (AREA)
  • Surgery (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Physics & Mathematics (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Eye Examination Apparatus (AREA)
  • Laser Surgery Devices (AREA)
  • Prostheses (AREA)
  • Medicines Containing Material From Animals Or Micro-Organisms (AREA)

Abstract

A fixation apparatus is provided that limits rotation of the ocular globe of an eye, to facilitate alignment of an instrument with the axis of astigmatism of the eye. The apparatus includes fixation target means (12) for locating in the field of view of the eye so that the eye may fixate on the target. The fixation target means includes or consists of at least one elongate component (16). Also disclosed is a corresponding method, and method and apparatus for supplying visual feedback to an operator during refractive surgery of an eye of a patient.

Description

    FIELD OF THE INVENTION
  • The present invention relates, in different aspects, to eye fixation and to the provision of visual feedback to a surgeon, during the delivery of medical laser procedures, particularly in the fields of ophthalmic surgical procedures, such as Photorefractive Keratectomy (PRK) and Laser-in-situ Keratomileusis (LASIK), or any laser based refractive correction. The invention will be described with reference to these applications, though it is to be understood that other applications are envisaged.
  • BACKGROUND ART
  • Most existing refractive laser delivery systems provide little feedback for the operator (typically a surgeon). Usually a crosshair graticule is superimposed through the microscope optics to help the operator aim the laser beam correctly onto the cornea. A fixation target or light, such as a flashing LED, is used to ensure that the patient's eye remains correctly aligned during the surgery. However, this arrangement does not necessarily provide the best alignment of the eye and the laser beam, nor does it provide visual feedback for the operator concerning the status of the eye or the laser. It may at times be necessary for the operator to move his or her attention away from the surgical field to check on instrumentation, such as the microkeratome or the laser source. The axis of astigmatism of the patient's eye is also likely to be misaligned when the patent is supine and fixating on a point of light.
  • Refractive errors are usually assessed when the patient is seated in an upright position using structured shapes or symbols, such as letters of the alphabet. However, refractive surgery is usually performed with the patient reclining in an operating chair. It has been found that, when a patient lies recumbent, the ocular globe is liable to rotate, altering the position of the axis of astigmatism between 7° and 16° in 25% of cases (Smith, Talamo, Assil & Petashnick, “Comparison of Astigmatic Axis in the Seated and Supine Positions”, J. of Refractive & Corneal Surgery 10(6), 615 (1994)). This occurs for two reasons: i) the removal of the reference horizon, and ii) the change from binocular to monocular vision. Focussing on a point of light (the flashing LED), instead of the linear horizon, does not provide a proper point of horizontal or vertical reference. The globe is therefore liable to rotate fractionally, possibly resulting in misalignment of the treatment of the eye's axis of astigmatism. The potential end result is under-treatment of the original astigmatic error or inducement of astigmatism at another axis.
  • U.S. Pat. No. 5,549,597 describes a method for determining the axis of astigmatism of a patient undergoing refractive surgery, so as to provide real-time alignment information for the surgical procedure. The patient is required to focus on a target such as three sets of three lines of variable line spacing, each set corresponding to a different visual acuity, and then to focus on the best resolved set of lines and rotate the target until the finest line is seen most clearly. This method of determining the axis of astigmatism and aligning the surgical laser is not ideal. The patient is forced to make subjective comparisons at a highly stressful time. In addition, the globe may still rotate after the alignment has been performed, and prior to surgery.
  • An earlier configuration for determining the axis of astigmatism is described in U.S. Pat. No. 3,785,723, and involves rotation of an opaque disk having multiple small apertures backlit by a light source so as to resemble a set of point light sources arranged in a straight line along the diameter of the disk.
  • U.S. Pat. No. 5,442,412 discloses a patient responsive eye fixation target for use in ophthalmic procedures in which respective light sources produce a ring of light and a dot of light centred on the same optical axis, but respectively closer to and further from the eye. In response to detection of a quantifiable amount of eye movement, the dot is altered in appearance, eg. by flashing or colour changes, to alert the patient that his or her eye is no longer aligned with the dot and ring.
  • Corresponding to the patient fixation apparatus is the apparatus used by the surgeon to view and assess the extent of fixation and the alignment of the laser beam. The surgeon views this display when looking down the surgical microscope. Current technology provides a display including a graticule or crosshair. A He—Ne beam is sometimes provided for aiming the surgical beam.
  • U.S. Pat. No. 4,870,964 provides a head-up display for use with an operating microscope during phaco-emulsification procedures. This apparatus allows the operating surgeon to view information about the status of the patient, the eye and operating equipment, such as vacuum pressure, without removing their gaze from the operating field. It does so by projecting light onto the operating field of the eye and conditioning the reflections from the cornea so that interpretable images may be viewed by the surgeon as they look down the microscope. U.S. Pat. No. 5,135,299 describes a similar operating microscope featuring a head-up display, produced by reflecting operational information from the scleral portion of the eye.
  • It is an object of the present invention, in at least one aspect, to provide an eye fixation method and apparatus that is simple and reliable, and involves minimal expectation of the patient. For particular applications, it is further preferred that the arrangement reduces the angular rotation of the ocular globe to facilitate alignment of an instrument with the axis of astigmatism.
  • It is an object of another aspect of the present invention to provide a surgical visual feedback method and apparatus that provides increased information to the surgeon or operator.
  • SUMMARY OF THE INVENTION
  • According, therefore, to a first aspect of the present invention, there is provided a method for limiting the rotation of the ocular globe of an eye to facilitate alignment of an instrument with the axis of astigmatism of the eye. The method includes providing fixation target means in the field of view of the eye so that the eye may fixate on the target. The fixation target means includes or consists of at least one elongate component having a fixed orientation.
  • Preferably the method includes providing the fixation target means by way of light emitting means. Preferably, the light emitting means is strobed.
  • The present invention also provides, in its first aspect, a fixation apparatus that limits rotation of the ocular globe of an eye, to facilitate alignment of an instrument with the axis of astigmatism of the eye. The apparatus includes fixation target means for locating in the field of view of the eye so that the eye may fixate on the target. The fixation target means includes or consists of at least one elongate component having a fixed orientation.
  • Preferably, said fixation target means includes or consists of at least two intersecting substantially mutually perpendicular elongate components. The fixation target means may consist substantially of a cross, and/or it may include more than two elongate components arranged as a grid. The fixation target means preferably has a fixed orientation.
  • The fixation target means may be a light emitting means. Moreover, the or each elongate component may be defined by the light emitting means.
  • Preferably, the light emitting means includes a plurality of light emitting diodes (LEDs) arranged in a respective linear array to define the or each elongate component.
  • Preferably the apparatus includes a printed circuit board (PCB) on which the LEDs are mounted.
  • Preferably the apparatus is controllable to strobe the light emitting means.
  • The apparatus may include a pulsable power supply to strobe the light emitting means.
  • In its first aspect, the invention extends to laser surgery apparatus incorporating patent observable fixation apparatus as described above.
  • In a second aspect of the present invention there is provided a method for supplying visual feedback to an operator during refractive surgery of an eye of a patient, including:
      • 1) providing fixation target means for the eye to fixate upon;
      • 2) locating the eye for viewing by viewing means while it is fixated upon said fixation target means;
      • 3) generating an information display of information pertinent to said surgery and suitable for displaying visually; and
      • 4) transmitting the information display to the viewing means for viewing by the operator;
      • whereby the eye and the information display may be viewed simultaneously by the operator.
  • Preferably the method includes updating the information display.
  • Preferably step 3) includes generating the information display with a controller means.
  • Preferably the controller means is a computer.
  • Preferably the method includes transmitting the information display to a display means and displaying the information display on the display means.
  • The display means may be miniature TV or LCD screen or a plurality of LEDs.
  • Preferably step 1) includes the alignment facilitating method according to the first aspect of the invention.
  • Preferably the viewing means includes left and right optics means, and the target is located between the left and right optics means.
  • Preferably the viewing means is a surgical microscope.
  • The invention extends to a method of performing refractive surgery on an eye of a patient, wherein visual feedback is supplied in accordance with the method of the second aspect of the invention. The refractive surgery may eg. be PRK or LASIK, thermal keratoplasty intrastromal ablation or any other surgical method that alters the refraction of the eye.
  • The method may be performed with any laser suitable for use in surgery that involves altering the refractive properties of the eye, e.g. an ultraviolet ablation laser, a Holmium laser, or an Erbium laser at 3 microns.
  • Preferably step 4) includes viewing said information by means of a beam splitter or plate of glass.
  • In its second aspect, the invention also provides an apparatus for supplying visual feedback to an operator during refractive surgery of an eye. The apparatus includes fixation target means for the eye to fixate upon, and viewing means for viewing the eye while it is fixated upon the fixation target means. Controller means is provided for generating an information display, and screen means displays the said information display, for viewing by the viewing means, whereby the eye and the information display may be viewed simultaneously by the operator.
  • Preferably the apparatus includes display means for displaying the information display.
  • The apparatus may be provided in combination with a surgical laser and thereby comprise laser surgery apparatus.
  • The laser may be any laser suitable for use in surgery that involves altering the refractive properties of the eye, such as a ultraviolet ablation laser, a Holmium laser, an Erbium laser at 3 microns or any other appropriate laser source.
  • Preferably the target means is a fixation apparatus according to the first aspect of the invention.
  • The display means and/or screen means may be viewed by means of a beam splitter or plate of glass.
  • Preferably the display means is a miniature TV or LCD screen or a plurality of LEDs.
  • Preferably the viewing means is a surgical microscope.
  • Preferably the controller means is a computer.
  • Preferably the viewing means includes left and right optics, and the target is located between the left and right optics.
  • In the method and apparatus of the second aspect of the invention, the information may include an alert signal indicating misalignment of the patient's eye, eg. due to straying from fixation upon the fixation target means.
  • The information may pertain to one or more of: the status of the patient, the surgery or the equipment, the position of the eye or where an eye tracker is aiming the laser.
  • The information may include one or more of the following elements of operational information: type of treatment, number of laser pulses required to finish, operation time remaining, patient identification and which eye is being treated, keratometry information, refraction information, and/or topographical information.
  • The information may include microkeratome status information, such as suction and blade speed readings.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • In order that the invention be more fully understood, preferred embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:
  • FIG. 1 is a schematic view of an eye fixation apparatus according to a preferred embodiment of the first aspect of the present invention;
  • FIG. 2 is a fragmentary view illustrating a suitable location for the eye fixation target; and
  • FIG. 3 is a diagram of the layout of the principal components of an arrangement for supplying visual feedback to an ophthalmic surgeon during refractive laser eye surgery procedures, according to a preferred embodiment of the second aspect of the present invention, but preferably incorporating the embodiment of FIGS. 1 and 2.
  • PREFERRED EMBODIMENTS
  • Referring to FIGS. 1 and 2, there is presented a schematic view of a patient's eye fixation apparatus 10 according to a preferred embodiment of the present invention. The apparatus 10 includes a fixation target in the form of a cross 12 formed by surface mounted light emitting diodes, LEDs 14, arranged in two linear arrays to define intersecting elongate components or axes 16, 18 perpendicular to one another. The LEDs are fixed to a printed circuit board (PCB) 13, in turn arranged on an elongate lipped substrate 15. Substrate 15 is positioned on the front of the surgical microscope 28, symmetrically between the adjacent stereo oculars 40,42, so as to be clearly observable by the patient. Alternatively, cross 12 may be located elsewhere within the surgical laser, and projected to optically appear as if it is placed between the oculars of the microscope.
  • Substrate 15 is fixed in position on the microscope so that cross 12 has a fixed orientation. “Vertical” axis 16 of the cross 12 of LEDs 14 is longer than “horizontal” axis 18, by providing several more LEDs 14 in axis 16 than axis 18. By “vertical” is meant the axis that extends normal to the lines joining the oculars. The LEDs 14 may alternatively be positioned to form any other pattern of elongate or linear elements, such as a line or a grid.
  • The cruciform arrangement of LEDs 14 allows the patient to better judge horizontal and vertical directions, so that the ocular globe(s) of the patient does not rotate and the axis of astigmatism is naturally aligned.
  • A suitable control circuit 20, of a simple form readily apparent to those skilled in the art, is provided for strobing LEDs 14 in a pre-selected, perhaps adjustable, sequence. The LEDs may, for example, flash in unison or in a more complex pattern. LEDs 14 may be of varying colours to facilitate patient concentration and gaze control. In use, the patient is required to fixate his or her gaze on the flashing cross 12, thereby preventing angular rotation of the ocular globe and misalignment of the treatment eye's axis of astigmatism. A preferred flash rate is about 1.5 Hz with a duty cycle of about 50%. The duty cycle may be adjustable, for example to allow more light during LASIK and less light during PRK.
  • FIG. 3 is a diagram of an apparatus 22 for supplying visual feedback to an ophthalmic surgeon during refractive laser eye surgery procedures being performed on an eye 24. This apparatus is an embodiment of the second aspect of the invention. The apparatus 22 includes a surgical microscope 28′, a fixation target 26, which is preferably a flashing cross 12′ as in FIGS. 1 and 2, on microscope 28′, a head-up display 30 to give the surgeon feedback regarding patient fixation, the operating conditions and other pertinent information, and an imaging device in the form of a miniaturised TV or LCD screen 32 supplied within the laser delivery head (not shown). The head-up display 30 may be produced by projecting lights onto a surface, as is known in the art, and may be displayed on screen 32. The imaging device may alternatively comprise a combination of light emitting diodes.
  • The apparatus 22 further includes a controller in the form of computer 34 and communications link 36 between computer 34 and screen 32. Computer 34 generates the information content (comprising information pertinent to the operation being carried out) of the head-up display 30, and transmits this content via link 36 to screen 32 to display. This content could include a pulse countdown, operation time remaining, an alert signal indicating misalignment of the patient's eye, a cross 31 indicating where the laser is currently aimed, patient information such as name or ID, treatment zone information, topographical information and any other information that the surgeon may deem useful.
  • The apparatus 22 also includes a beamsplitter 38, by which the head-up display 30 is viewed. The beamsplitter 38 forms a part of the optics of the laser (not shown), for relaying this information towards oculars 40′, 42′ of the microscope 28′, so that the operator may see the information when he or she looks down the microscope 28′.
  • Thus, in use, while the patient views (50) a suitable fixation target 26 (such as a fixation cross 12′ as described above), the surgeon is able to view the patient's eye 24 (51) and the head-up display 30 (52) through the surgical microscope 28′.

Claims (23)

1-41. (canceled)
42. Apparatus for supplying visual feedback to an operator during refractive surgery of an eye, including:
fixation target means for said eye to fixate upon;
viewing means for viewing said eye while it is fixated upon said fixation target means;
controller means for generating an information display; and
screen means for displaying said information display for viewing by said viewing means;
whereby said eye and said information display may be viewed simultaneously by said operator.
43. Apparatus according to claim 42, further including display means for displaying said information display.
44. Apparatus according to claim 42, wherein said fixation target means includes or consists of at least one elongate component.
45. Laser surgery apparatus, including a surgical laser and apparatus for supplying visual feedback during laser surgery performed on an eye wherein the laser apparatus includes the apparatus according to claim 42.
46. Apparatus according to claim 42, wherein said screen means is a miniature TV or LCD screen or a plurality of LEDs.
47. Apparatus according to claim 42, wherein said viewing means is a surgical microscope.
48. Apparatus according to claim 42, wherein said controller means is a computer.
49. Apparatus according to claim 42, wherein said information includes an alert signal indicating misalignment of the patient's eye.
50. Apparatus according to claim 42, wherein said information pertains to one or more of: the status of the patient, the surgery, the equipment, the position of the eye, and where an eye-tracker is aiming the laser.
51. Apparatus according to claim 42 wherein said information includes one or more of the following elements of operational information: type of treatment, number of laser pulses required to finish, operation time remaining, patient identification and which eye is being treated, keratometry information, refraction information, and/or typographical information.
52. A method of supplying visual feedback to an operator during refractive surgery of an eye of a patient, including:
1) providing fixation target means for said eye to fixate upon;
2) locating said eye for viewing by said operator by means of viewing means while the eye is fixated upon said fixation target means;
3) generating an information display of information pertinent to said surgery and suitable for displaying visually; and
4) transmitting said information display to said viewing means for viewing by said operator;
whereby said eye and said information display may be viewed simultaneously by said operator.
53. The method according to claim 52, wherein said information display is updated.
54. The method according to claim 52, wherein said information display is generated with a controller means.
56. A method according to claim 54, further including transmitting said information display to a display means and displaying said information display on said display means.
56. The method according to claim 55, wherein said fixation target means provided includes or consists of at least one elongate component.
57. A method of performing refractive surgery on an eye of a patient wherein visual feedback is supplied in accordance with claim 52.
58. A method according to claim 52, wherein said information includes an alert signal indicating misalignment of the patient's eye.
59. A method according to claim 52, wherein said information pertains to one of more of: the status of the patient, the surgery, the equipment, the position of the eye, or where an eye-tracker is aiming the laser.
60. A method according to claim 52, wherein said information includes one or more of the following elements of operational information: type of treatment, number of laser pulses required to finish, operation time remaining, patient identification and which eye pulses required to finish, operation time remaining, patient identification and which eye is being treated, keratometry information, ref refraction information, and/or topographical information.
61. A method according to claim 52, wherein said fixation target means is provided so as to have a fixed orientation.
62. An apparatus according to claim 42 wherein said fixation target means has a fixed orientation.
63. A method according to claim 52, wherein said fixation target means is provided so as to have a fixed orientation.
US11/354,718 1998-08-14 2006-02-15 Surgical visual feedback and eye fixation method and apparatus Abandoned US20080249512A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/354,718 US20080249512A1 (en) 1998-08-14 2006-02-15 Surgical visual feedback and eye fixation method and apparatus

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
AUPP5284 1998-08-14
AUPP5284A AUPP528498A0 (en) 1998-08-14 1998-08-14 Surgical visual feedback and eye fixation method and apparatus
US09/762,824 US7001018B1 (en) 1998-08-14 1999-08-16 Surgical visual feedback and eye fixation method and apparatus
PCT/AU1999/000665 WO2000009002A1 (en) 1998-08-14 1999-08-16 Surgical visual feedback and eye fixation method and apparatus
US11/354,718 US20080249512A1 (en) 1998-08-14 2006-02-15 Surgical visual feedback and eye fixation method and apparatus

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
US09/762,824 Division US7001018B1 (en) 1998-08-14 1999-08-16 Surgical visual feedback and eye fixation method and apparatus
PCT/AU1999/000665 Division WO2000009002A1 (en) 1998-08-14 1999-08-16 Surgical visual feedback and eye fixation method and apparatus

Publications (1)

Publication Number Publication Date
US20080249512A1 true US20080249512A1 (en) 2008-10-09

Family

ID=3809516

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/762,824 Expired - Fee Related US7001018B1 (en) 1998-08-14 1999-08-16 Surgical visual feedback and eye fixation method and apparatus
US11/354,718 Abandoned US20080249512A1 (en) 1998-08-14 2006-02-15 Surgical visual feedback and eye fixation method and apparatus

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/762,824 Expired - Fee Related US7001018B1 (en) 1998-08-14 1999-08-16 Surgical visual feedback and eye fixation method and apparatus

Country Status (7)

Country Link
US (2) US7001018B1 (en)
EP (1) EP1109484B1 (en)
AT (1) ATE363227T1 (en)
AU (1) AUPP528498A0 (en)
CA (1) CA2339861A1 (en)
DE (1) DE69936214T2 (en)
WO (1) WO2000009002A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070126985A1 (en) * 2005-10-28 2007-06-07 Wiltberger Michael W Photomedical treatment system and method with a virtual aiming device
WO2013052259A1 (en) * 2011-10-05 2013-04-11 Alcon Research, Ltd. Surgical heads-up display that is adjustable in a three- dimensional field of view

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6283954B1 (en) 1998-04-21 2001-09-04 Visx, Incorporated Linear array eye tracker
US6322216B1 (en) 1999-10-07 2001-11-27 Visx, Inc Two camera off-axis eye tracker for laser eye surgery
DE10052201B8 (en) * 2000-10-20 2005-06-30 Carl Zeiss Meditec Ag Method and device for identifying a patient and an operating area
US20050277913A1 (en) * 2004-06-09 2005-12-15 Mccary Brian D Heads-up display for displaying surgical parameters in a surgical microscope
CA2803828C (en) * 2005-03-31 2015-11-24 Alcon, Inc. Footswitch operable to control a surgical system
US7800820B2 (en) 2006-06-30 2010-09-21 Richard Awdeh Microscope viewing device
US8109937B2 (en) * 2007-02-23 2012-02-07 Alcon Research, Ltd. Surgical system for indication of media types
US8465473B2 (en) * 2007-03-28 2013-06-18 Novartis Ag Surgical footswitch with movable shroud
US7981109B2 (en) * 2007-08-15 2011-07-19 Novartis Ag System and method for a user interface
JP2011522609A (en) * 2008-06-05 2011-08-04 アルコン リサーチ, リミテッド Wireless network and wireless communication method for an ophthalmic surgical console
JP5337609B2 (en) * 2009-07-15 2013-11-06 日立コンシューマエレクトロニクス株式会社 Broadcast receiver
EP2294969A1 (en) * 2009-09-11 2011-03-16 Medical Workshop B.V. Device for eye fixation
US20110238431A1 (en) * 2010-03-23 2011-09-29 Robert Cionni Surgical Console Information Management
JP6012614B2 (en) 2010-11-05 2016-10-25 フリーダム メディテック インコーポレイテッド Apparatus and method for non-invasively detecting diseases affecting the structural properties of biological tissue
JP2013039148A (en) * 2011-08-11 2013-02-28 Topcon Corp Microscope for ophthalmic operation
JP2013046649A (en) * 2011-08-29 2013-03-07 Topcon Corp Microscope for ophthalmic surgery
US8970959B2 (en) 2012-04-17 2015-03-03 Endure Medical, Inc. Stereoscopic beam splitter
JP6462209B2 (en) * 2013-12-03 2019-01-30 浜松ホトニクス株式会社 Measuring device and measuring method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4678297A (en) * 1982-11-30 1987-07-07 Canon Kabushiki Kaisha Ophthalmic instrument
US5562656A (en) * 1992-07-31 1996-10-08 Nidek Co., Ltd. Ophthalmic apparatus
US6004313A (en) * 1998-06-26 1999-12-21 Visx, Inc. Patient fixation system and method for laser eye surgery
US6585723B1 (en) * 1998-09-04 2003-07-01 Nidek Co., Ltd. Corneal surgery apparatus

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3025755A (en) * 1958-09-22 1962-03-20 Robert C Mueller Visual field examination device
US3785723A (en) 1973-02-27 1974-01-15 D Guyton Method and apparatus for locating a principal meridian of an astigmatic optical system
US4536065A (en) * 1982-09-29 1985-08-20 Sheingorn Larry A Fixation device for eye testing
DE3579947D1 (en) 1984-06-05 1990-11-08 Univ Glasgow METHOD AND DEVICE FOR DETECTING FIELD OF FIELD.
US4923297A (en) * 1986-06-23 1990-05-08 Eyedentify, Inc. Optical alignment system
US4870964A (en) * 1988-06-16 1989-10-03 Paul F. Bailey, Jr. Opthalmic surgical device and method with image data reflected off of the eye
JPH02150202A (en) * 1988-11-29 1990-06-08 Konan Camera Kenkyusho:Kk Apparatus for taking up image of eyeball movement using target
JP3028421B2 (en) * 1989-12-14 2000-04-04 株式会社トプコン Surgical microscope
US5094521A (en) * 1990-11-07 1992-03-10 Vision Research Laboratories Apparatus for evaluating eye alignment
US5841511A (en) * 1992-06-02 1998-11-24 Eyesys Technologies, Inc. Method of corneal analysis using a checkered placido apparatus
US5549597A (en) * 1993-05-07 1996-08-27 Visx Incorporated In situ astigmatism axis alignment
US5442412A (en) 1994-04-25 1995-08-15 Autonomous Technologies Corp. Patient responsive eye fixation target method and system
US5784148A (en) * 1996-04-09 1998-07-21 Heacock; Gregory Lee Wide field of view scanning laser ophthalmoscope
GB9613766D0 (en) 1996-07-01 1996-09-04 Life Science Resources Ltd Medical laser guidance apparatus
US6666855B2 (en) * 1999-09-14 2003-12-23 Visx, Inc. Methods and systems for laser calibration and eye tracker camera alignment

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4678297A (en) * 1982-11-30 1987-07-07 Canon Kabushiki Kaisha Ophthalmic instrument
US5562656A (en) * 1992-07-31 1996-10-08 Nidek Co., Ltd. Ophthalmic apparatus
US6004313A (en) * 1998-06-26 1999-12-21 Visx, Inc. Patient fixation system and method for laser eye surgery
US6585723B1 (en) * 1998-09-04 2003-07-01 Nidek Co., Ltd. Corneal surgery apparatus

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070126985A1 (en) * 2005-10-28 2007-06-07 Wiltberger Michael W Photomedical treatment system and method with a virtual aiming device
US10524656B2 (en) * 2005-10-28 2020-01-07 Topcon Medical Laser Systems Inc. Photomedical treatment system and method with a virtual aiming device
US11406263B2 (en) 2005-10-28 2022-08-09 Iridex Corporation Photomedical treatment system and method with a virtual aiming device
WO2013052259A1 (en) * 2011-10-05 2013-04-11 Alcon Research, Ltd. Surgical heads-up display that is adjustable in a three- dimensional field of view

Also Published As

Publication number Publication date
ATE363227T1 (en) 2007-06-15
EP1109484A4 (en) 2004-08-04
WO2000009002A1 (en) 2000-02-24
AUPP528498A0 (en) 1998-09-10
CA2339861A1 (en) 2000-02-24
EP1109484B1 (en) 2007-05-30
DE69936214T2 (en) 2008-01-31
US7001018B1 (en) 2006-02-21
DE69936214D1 (en) 2007-07-12
EP1109484A1 (en) 2001-06-27

Similar Documents

Publication Publication Date Title
US20080249512A1 (en) Surgical visual feedback and eye fixation method and apparatus
AU2007243355B2 (en) Dynamic optical surgical system utilizing a fixed relationship between target tissue visualization and beam delivery
US7284861B2 (en) Ophthalmic apparatus and corneal surgery apparatus
US7252661B2 (en) Method and system for patient optical fixation
ES2663535T3 (en) Device and method for laser-assisted deep sclerectomy
US20110040294A1 (en) Method and device for the representation of an operation area during laser operations
CN101304710B (en) System and method for correction of ophthalmic refractive errors
DE69826762T2 (en) Laser treatment device
US20120303009A1 (en) Cornea center positioning method for excimer laser keratomileusis
US6217570B1 (en) Method of aligning the optical axis of a laser for reshaping the cornea of a patients eye with the visual axis of the patient's eye
EP1192919B1 (en) Laser surgery apparatus
EP1200026B1 (en) Device for ophthalmologically treating the eye using a fixation light beam
Mandell Locating the corneal sighting center from videokeratography
US5947955A (en) Active eye movement and positioning control device
Gobbi et al. Automatic eye tracker for excimer laser photorefractive keratectomy
AU753444B2 (en) Surgical visual feedback and eye fixation method and apparatus
US20240041654A1 (en) Assembly for laser treatment of ocular opacities
CN106659379A (en) Technique for centering an application field
Mandelcorn et al. Unassisted scleral depression during vitrectomy surgery: two simple, cost-effective techniques
JP2014516279A (en) Apparatus for treating eyes with a laser beam
US9259145B2 (en) Apparatus and method for testing night vision
JP2002282298A (en) Corpus ciliare light coagulation probe and ophthalmic laser device having it
ES2886133T3 (en) Improvements related to retinal treatment
Peyman et al. External infrared light for excimer laser vision correction
JP2022043245A (en) Optometer

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION