Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS 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
  • A61F9/00—Methods 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
  • A61F9/007—Methods or devices for eye surgery
  • A61F9/008—Methods or devices for eye surgery using laser
  • A61F9/00821—Methods or devices for eye surgery using laser for coagulation
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N5/0613—Apparatus adapted for a specific treatment
  • A61N5/062—Photodynamic therapy, i.e. excitation of an agent
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
  • A61B2018/2035—Beam shaping or redirecting; Optical components therefor
  • A61B2018/20361—Beam shaping or redirecting; Optical components therefor with redirecting based on sensed condition, e.g. tissue analysis or tissue movement
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/18—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves
  • A61B18/20—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by applying electromagnetic radiation, e.g. microwaves using laser
  • A61B2018/2065—Multiwave; Wavelength mixing, e.g. using four or more wavelengths
  • A61B2018/207—Multiwave; Wavelength mixing, e.g. using four or more wavelengths mixing two wavelengths
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS 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
  • A61F9/00—Methods 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
  • A61F9/007—Methods or devices for eye surgery
  • A61F9/008—Methods or devices for eye surgery using laser
  • A61F2009/00844—Feedback systems
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS 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
  • A61F9/00—Methods 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
  • A61F9/007—Methods or devices for eye surgery
  • A61F9/008—Methods or devices for eye surgery using laser
  • A61F2009/00861—Methods or devices for eye surgery using laser adapted for treatment at a particular location
  • A61F2009/00863—Retina
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS 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
  • A61F9/00—Methods 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
  • A61F9/007—Methods or devices for eye surgery
  • A61F9/008—Methods or devices for eye surgery using laser
  • A61F9/00821—Methods or devices for eye surgery using laser for coagulation
  • A61F9/00823—Laser features or special beam parameters therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N2005/063—Radiation therapy using light comprising light transmitting means, e.g. optical fibres
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N2005/0635—Radiation therapy using light characterised by the body area to be irradiated
  • A61N2005/0643—Applicators, probes irradiating specific body areas in close proximity
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N2005/0664—Details
  • A61N2005/0667—Filters
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
  • A61N5/00—Radiation therapy
  • A61N5/06—Radiation therapy using light
  • A61N5/067—Radiation therapy using light using laser light

Definitions

• This invention relates generally to lasers, and more particularly to photodynamic therapy laser systems which are compact, portable and easier to use in a treatment facility.
• Photodynamic therapy is a non-invasive medical procedure used for the treatment of various diseases. PDT involves the administration of a photosensitizing compound that concentrates around a portion of tissue. Thereafter the tissue that is concentrated with the photosensitizing compound is irradiated. The target tissue containing a sufficiently high concentration of the photosensitizing compound selectively absorbs the light which induces impairment or destruction of the immediately surrounding cells.
• Age-related macular degeneration results in the loss of vision in the macula due to damage in the retina.
• the wet (or excudative) form of age-related macular degeneration occurs when blood vessels spread from the choroid behind the retina. This abnormal blood vessel growth can cause detachment of the retina.
• the detachment of the retina can be avoided by preventing the spread of abnormal blood vessel growth. The spread is prevented by irradiating a photosensitizing compound in a tissue that causes impairment or destruction of the surrounding cells through a cytotoxic effect.
• a method of PDT is described in U.S. Patent No. 5,756,541, the entirety of which is incorporated by reference.
• Visudyne® is used to treat the wet form of age-related macular degeneration.
• Visudyne® is discussed in U.S. Patent Nos. 5,171,749, 5,095,030, 5,707,608, 5,770,619, 5,798,349, and 6,074,666, the entireties of which are incorporated by reference.
• Visudyne® is administered intravenously for approximately ten minutes. After approximately fifteen minutes, the treatment site is activated with laser light having a wavelength of approximately 689 nm at 150-600 mW/m 2 ,
• verteporfin is the generic form or equivalent of Visudyne
• CSC central serous chorioretinopathy
• PCV polypoidal chorodial vasculopathy
• CNV neovasculizatioii
• a treatment beam and an aiming beam is generated from a single laser head.
• the beams are transmitted through a fiber optic cable which provides mode-mixing for spot uniformity.
• the laser light is then expanded and collimated.
• the collimated laser light is propagated through an aperture wheel that is configured to set a spot size.
• the light from the aperture wheel is propagated through a lens wherein it is focused from the lens onto a partially reflective mirror.
• the partially reflective mirror is configured to reflect a high percentage of the treatment beam and partially reflect a smaller percentage of the aiming beam into a patient's eye.
• light from the partially reflective mirror is propagated to the treatment site wherein the light beam that irradiates the treatment site has a top hat profile of fluence for each desired spot size
• the laser head is designed to run at a higher power output but actuall run at a lower power output to generate less heat.
• a tonometer post allows the optical system to be removably attachable to a slit lamp microscope.
• heat from tlie laser head is dissipated in a heat sink.
• the heat sink is coupled to a fin array.
• the fin array may be coupied to the heat sink with a heat pipe.
• the invention provides a laser system configured for administering therapy to a patient.
• the laser system includes: a laser source operable to emit a first laser beam having a first operating wavelength and a second laser beam having a second operating wavelength; a fiber optic cable to guide and homogenize the first and second laser beams; an expander to increase tlie diameter of the first and second laser beams; a cylinder to guid e the first and second laser beams and limit respective diameters of the first and second laser beams, wherein tlie cylinder is positioned after the expander on an optical path of the laser beam; a first optical system to collimate the first and second laser beams, wherein tlie optical system is positioned after the cylinder on the optical path of the first and second laser beams; a spot-size selector comprising a plurality of apertures,, wherein the spot-size selector is positioned after the first optical system on the optical path of the first and second laser beams; a second optical system to focus the first and second laser
• a laser system configured for administering therapy to a patient, includes: a laser source operable to emit a first laser beam operating a first wavelength and a second laser beam operating at a second wavelength, wherein the laser source operates at 1.5 watts or less; a passive cooling system, wherein the passive cooling system comprises a heat pipe, a heat sink, and a fin array; a fiber optic cable coupled to the laser source and configured to guide and homogenize the first and second laser beams; a first optical system coupled to the fiber optic cable and configured to increase the diameter of and collimate the first arid second laser beams; a spot-size selector coupled te.the first optical system and comprising a plurality of apertures; and a second optical system coupled to the spot-size selector and configured to focus the laser beam on an eye tissue of the patient.
• a laser system configured for administering therapy to a patient, includes: a laser source operable to emit a first laser beam having a first operating wavelength and a second laser beam having a second operating wavelength; a fiber optic cable to guide and homogenize the first and second laser beams, wherein the fiber optic cable has a diameter of about 350 to 450 microns and a length of about 200 to 300 millimeters; a first optical system coupled to the fiber optic cable and configured to increase the diameter of and collimate the first and second laser beams; a spot-size selector coupled to the first optical system and comprising a plurality of apertures, wherein the spot-size selector is positioned after the first optical system on the optical path of the first and second laser beams, and the fiber optic cable is the only fiber optic cable between the laser source and the spot-size selector; and a second optical system coupled to the spot-size selector and configured to focus the laser beam on an eye tissue of the patient.
• a method of activating a photoactive drug administered to a patient intravenously includes: activating the photoactive agent with a first laser beam generated by a laser apparatus, the first laser beam having a first wavelength; generating a second laser beam operating at a second wavelength, wherein the combined power levels of both the first a d second laser beams are 1.5 watts or lessi; passively cooling the laser apparatus by coupling a heat sink to a laser source of the laser apparatus; guiding the first and second laser beams through a fiber optic cable coupled to the laser source,, wherein the fiber optic cable homogenizes tlie first and second laser beams; eollimating the first and second laser beams; adjusting a spot-size of the first and second laser beams; and focusing the first and second laser beams on an eye tissue of the patient, wherein at least the first laser beam activates tlie photoactive drug within the patient's eye tissue to provide therapy to the patient.
• the photo activate agent comprises vertepor
• Figure 1 illustrates exemplary components of a compact PDT laser according to one embodiment of the invention
• Figure 2 illustrates an exemplary partially reflective mirror according to one embodiment of the in vention
• Figure 3 illustrates an exemplary reflection profile for a partially reflective mirror according to one embodiment of the in vention.
• Figure 4 iliustrates an exemplary top hat output profile for a PDT laser according to one embodiment of the invention
• Figure 5 illustrates the fully assembled internal components of an exemplary PDT laser according to one embodiment of the invention.
• Figure 6 illustrates a modular view of an exemplary low-cost PDT laser according to one embodiment of the invention
• Figures 7(a)-(b) illustrate an exemplary PDT laser having a housing according to one embodiment of the invention.
• Figure 8 illustrates an exemplary PDT laser having a portion of the housing made transparent for illustrative purposes according to an embodiment of the invention.
• Figure 9 illustrates an exemplary beam splitting system to provide coincident treatment and aiming lasers according to an embodiment of the invention.
• Figure 10 illustrates an exemplary split fiber system to provide coincident treatment and aiming lasers according to an embodiment of the invention.
• Figure 11 illustrates an exemplary laser bar system to provide coincident treatment and aiming laser beams according to an embodiment of the invention.
• Figure 12 illustrates an exemplary user interface that enables an operator to setup a laser and perform therapy therewith.
• Figures 13 and 14 illustrate some exemplary combinations of aperture size, spot size, and system magnification, in accordance with one embodiment of the invention.
• Fsgssre IS illustrates exemplary process flow earned out by software or other circuitry to e ecute steps for performing a laser-based therapy treatment, such as the treatments described herein.
• Figures 16(a) and 16(b) illustrate an exemplary PDT laser according to an embodiment of the invention, mounted on a slit lamp, with a mannequin's head at the position of the patient's head.
• Figure 1 illustrates an exploded view of an exemplary PDT laser system 10 ⁇ wherein each individual component is shown disconnected from the other individual components.
• Laser light is generated from the laser head 1 ⁇ 2.
• the laser head may be obtained commercially (e.g., nLIGHT PearlTM) or may be constructed of any number of laser generation components (e.g., pump diodes, gas lasers), it. is understood that any laser design capable of providing two or more coincident beams may be utilized.
• the laser head 102 generates a treatment and an aiming beam.
• the treatment beam has a spot size that is variable from 350 ⁇ to 5000 pm.
• the laser head 102 can generate fluence rates of 50 mW/cm 2 , 300 mW/cm 2 , 450 mW/cm 2 , and 600 mW/cm 2 . in further embodiments, contact lens magnification is accounted for when calculating the required fluence rate.
• 90% of the treatment beam output power is in the spectral range of 689 nm ⁇ 3 nm in order to effectively activate a photosynthesizing agent (e.g., Visudyne®),
• the aiming beam may have a spectra! output in the range of 635 nm ⁇ 10 nm. It should be understood that the invention is not limited to the spot sizes, fluence rates and treatment beam ranges disclosed, and the parameters listed above are for exemplary purposes only,
• the circularity (the normalized ratio of the minor to the major axis of an ellipse fitted to the beam output) is greater than 0.870 for all spot sizes.
• the beam shall have uniform power distribution throughout.
• the uniformity sigma is no greater than 20% when defined as the standard deviation of the intensity of the beam image calculated by: where P is the pixel value, M is the mean pixel value and N is the total number of pixels inside the analysis area. According to one embodiment, the beam profile does not deviate from the equation above during treatment.
• the laser head ⁇ 02 provides a light dose of 12.5 J/cm 2 , 25 J/cm 2 , 37.5 J/cm 2 , or 50 J/cm 2
• the exposure duration can be automatically controlled to deliver a requested light dose at a requested flueace.
• the laser head 102 will automatically shut off.
• the diameter and position of the aiming beam is coincident with the treatment beam so that a health care professional can adequately apply the treatment beam to the treatment spot.
• the output power of the aiming beam is 1 mW or less.
• the visibility of the aiming beam is adjustable (e.g., from barely visible to maximum visibility).
• the wavelength of the aiming beam is in the range of 625-645nm.
• the current invention combines a treatment beam and aiming beam in a single laser head 102, whereby these embodiments of the present invention advantageously allow the laser head 102 to be mounted on a typical optical system rather than as a stand-alone console as provided by conventional laser systems.
• a further benefit to combining the treatment and aiming beam is a more compact PDT laser system 100, which can be more compact, economical to manufacture, as well as more portable and useable in a treatment facility.
• the laser head 102 may be current controlled.
• a current controlled laser head 102 may be manufactured inexpensively and by controlling the maximum current to the laser, safety is improved.
• the laser head 102 may be engineered to operate at a higher power (e.g., 5 W) wherein it is actually run at a lower power (e.g., 1 W or 1.5 W) to reduce heat output and extend useful life.
• any method of current control may be utilized.
• current may be controlled by an external foot pedal, a knob, a computer, or any other device known in the art.
• a current control device may be located on the laser head 102.
• the laser head 102 may be voltage controlled (e.g., voltage corresponding to beam intensity) or controlled by digital communication signals.
• the laser bead 102 can be made to ran below specification at 1 to 1.5 to generate less heat.
• the laser head 102 is configured to run at a power level of approximately 325 mW to 750mW to further reduce heat generation. The lower heat generated allows the laser head 102 to be passively cooled.
• a heat sink 108 is coupled to the laser head 102,
• the heat sink ICS is coupled to a heat pipe 106 that transfers heat to a fin array 104.
• the fin array 104 dissipates the heat into the air.
• the heat sink 108, heat pipe 106, and fin array 114 may be made of any material known in the art to disperse the heat.
• the cooling system may utilize working fluid as known in the field of heat transfer in order cool the laser head 102.
• the heat sink 108, the heat pipe 106, and/or the fin array 104 may be filled with a small quantity of working fluid (e.g., water, acetone, nitrogen, methanol, ammonia, or sodium, etc.). Heat is absorbed by vaporizing the working fluid. The vapor transports heat to the condenser region where the condensed vapor releases heat to a cooling medium. The condensed working fluid is returned to the evaporator by gravity, or by a wick structure on the heat pipe 106 or fin array 104, creating capillary action.
• working fluid e.g., water, acetone, nitrogen, methanol, ammonia, or sodium, etc.
• the passive cooling system contributes to reducing the cost of the exemplary PUT laser in a number of ways.
• the passive cooling system isless expensive than active cooling systems of the prior art.
• the passive cooling system cost less to manufacture, to maintain, and to operate when compared to active cooling systems.
• the passive coolmg system is more compact than active systems, allowing the cooling system to be installed in a housing with the laser, and the housing positioned on known slit lamp microscopes.
• the heat sink 108 can assist the laser head 102 to keeping the therapeutic wavelength within ⁇ lnm and the therapeutic energy within 3% of the desired treatment fiuenee.
• the laser head 102 has a heat dissipation area of approximately 1 L4 cm by 2.86 cm. Therefore, by having ten times or more surface area for heat dissipation could allow the laser head 102 to operate within therapeutic parameters.
• a metal sheet housing may be utilized to dissipate heat of the laser head 102,
• the heat sink 108, the heat pipe 106, and the fin array 104 provide approximately a 25 times factor increase in surface area for heat dissipation.
• the heat pipe W6 may be utilized to deliver heat to the fin array 104 mat can be placed at any convenient location within the instrument enclosure.
• the 32,6 cm 2 heat dissipation surface of the laser head 102 is attached to a heat sink 108 in combination with a heat pipe 106 and a fin array 104 wherein the heat distribution structure has a 810 cm 2 heat dissipation surface.
• the laser head 102 may be optimally placed near the optical components and the heat may be transferred to a convenient location on or outside of the PDT laser system.
• the two laser beams from the laser head 102 are propagated through a fiber optic cabl 110,
• the fiber optic cable 110 has a curve is the Z- axis. This Z-axis curve works as a mode-scrambler. Mode scrambling distributes the optical power in a fiber among all the guided modes.
• One known scrambling technique Is to splice a length of graded-mdex fiber between two pieces of step-index, but such techniques are expensive and add the complication of fiber alignment
• curving the fiber in the Z ⁇ axis reduces cost and eliminates the complications of fiber alignment.
• short fiber optic cable 250mm, for example) causes rapid coupling between all fiber modes and attenuation of high order modes.
• the fiber optic cable 110 outputs a uniform output intensity profile and circularity independent of the intensity profile of the laser head 102.
• the fiber optic cable 110 is about 250 mm in length and has a diameter of about 400 microns. Given the smaller size of the fiber optic cable 110, it may be positioned on the optical system.
• prior art. systems had long fiber optic- cables connecting a laser head to the slit lamp optical system. Prior art. systems suffer from degradation of the fiber optic cable and breakage.
• the shorter fiber optic cable 110 of embodiments of the present invention is more robust and more cost efficient,
• the fiber optic cable IW may connect to a fiber lens (not shown) having 4,5 mm focal length (FL).
• the expanded light is outpuited from the laser beam expander 112 into the light diverger 14 that diverges the light.
• the beam expander 112 may have a lens having a 4 ⁇ mm FL.
• the beam expander 112 comprises a biconcave lens having negative power, A diverging beam propagates the length of the beam expander 112 tube , which provides additional beam divergence to the beam.
• the diverged light propagates from the diverger 114 to the collimator 116,
• the light that is o tputied from the collimator 116 is snore parallel s relative to the inputted light, in a specific direction and its spatial cross section is smaller. Further, the light exiting the collimator has a substantially uniform fluenee.
• the light is collimated so it may pass through a mechanical device and still provide uniform fluenee on the target site.
• the fiber optic cable 3.1.0, the expander 112, the diverger 1 4, and the collimator 116 axe provided as exemplary embodiments, it is understood that alternative mechanisms in the art or additional components may be utilized to deliver light of a uniform fluenee.
• fe SSf The light from the collimator 116 ' is propagated to the aperture wheel 118.
• the aperture wheel 118 comprises a series of apertures to set different spot sizes for the treatment beam, The spot sizes .may be physically set by a person manually rotating the aperture wheel to . the desired spot size. In other embodiments, a motorized system may rotate the wheel after a desired spot size is selected by a user or a computer system.
• the aperture wheel 118 is configured to provide beam diameters of 1.22 mm to 5.5 mm s in twelve approximately equal steps. In some embodiments, these beam diameters translate to spot sizes of 1.0 mm to 6.4 mm, when appropriate contact lenses are used.
• one spot of 500 microns is delivered by the aperture wheel 118 for tlie treatment of polypoidal choroidal vasculopathy and a range of spots f om 1000 to 6400 microns with an average step increment of approximately 400 microns is delivered for PDT.
• the PDT laser provides laser spot sizes smaller than imm for CSC, PCV, CNV, age-related macular degeneration (AMD) or similar indications.
• a single aperture wheel 118 is utilized. This provides costs savings as a metal wheel can be manufactured cheaper than a lens or a zoom system.
• aperture wheel 118 is more durable than a lens system and less likely to degrade or become misaligned over time. Further, the aperture wheel 118 is easily interchangeable or replaceable with other aperture wheels. For example, a new series of spot sizes may be utilized by cheaply replacing the aperture wheel 118 having a set of spot size values to another aperture wheel having a different set of spot size values.
• the aperture wheel 118 can be configured to provide spot sizes of 500-6000 microns.
• the lens assembly 120 focuses the image of the aperture wheel 118 to have a 1 : 1 inpufcOutput ratio and projects light to a partially reflective mirror 122.
• the lens assembly 120 comprises two lenses (120a and 120b).
• the first lens 120a may have a 56mm focal length (FL) and the second lens 120b may have a 48mm FL.
• both lenses of the lens assembly 120 may have a 50 mm FL.
• Figure 2 illustrates an aiming beam 124 propagated onto an exemplary partially reflective mirror 122 from the lens assembly 120 ( Figure 1). Approximately 50% of the aiming beam 124 is reflected by the partially reflective mirror 122 to the patient's eye 126.
• the partially reflected light beam 128 illuminates a target site 130 of the patient's eye 126.
• a portion of the reflected beam 128 is reflected off the target site 130.
• Approximately 50% of the light that is reflected off of the target site 130 is again reflected by the partially reflected mirror 122.
• the other 50% of light reflected off of the target site 130 is transmitted through the partially reflective mirror 122 to the optics of the slit lamp and ultimately to the clinician's eyes. This enables the clinician to see the target site 130 of the patient's eye 126.
• the total light emission, sinking &e physician's eye does not exceed safe limits as defined by the American National Standard for Safe Use of Lasers (ANSI Z136). the disclosure of which is herein incorporated by reference in its entirety.
• ANSI Z136 provides safe laser exposure limits for general use. If the laser exposure is below the limits defined by the standard there should be no thermal damage to the ret nal tissues due to laser exposure alone,
• the partially reflective mirror 122 can act similarly to reflect the treatment beam.
• the partially reflective mirror 122 can be configured to reflect 90% of the treatment beam.
• the reflected treatment beam would propagate onto the eye 126 and only a small portion of that beam would be reflected back to the partially reflected mirror 122.
• 10% of the light from the tissue reflected light ld be propagated to the clinician's eyes.
• the small percentage of the treatment beam ultimately propagated to the clinician's eyes would not be harmful.
• the total light emission striking the physician's eye does not exceed safe limits as defined by ANSI Z136, the disclosure of which is herein incorporated by reference in its entirety.
• Figssre 3 illustrates an exemplary reflective profile for the partially reflective mirror 122.
• a treatment beam has a wavelength of 689 nm and an aiming beam has a wavelength of 635 am.
• the partially reflective mirror 122 would reflect 90% of the treatment beam and 50% of the aiming beam,
• a partially reflective mirror 1.22 may have any alternative desired reflective profiles,
• top hat beam is understood in the art and is a laser beam that has a near uniform fluence within a circular disk.
• Figure 4 illustrates an exemplary top hat profile for a spot size of 4600 microns for the X and the Y plane that is propagated onto the eye 126.
• the PDT laser has a maximum total power of 200 mW for the largest spot size of the laser.
• any spot size may be selected to be propagated at any desired power density depending on the desired application.
• the top hat profile may be optimized for more uniform distribution.
• the tonometer post 134 may be used to attach the PDT laser system 100 to a conventional slit lamp microscope.
• the tonometer post 134 is designed to couple to a Haag-Strait or equivalent slit lamp microscope. It. is understood that the tonometer post 134 is exemplary and that an equivalent attachment mechanism may be provided to attach the PDT Laser system 100 to a slit lamp microscope or other similar ophthalmic device.
• the PDT laser system ⁇ 00 is mounted on a slit lamp microscope so that the treatment spot is aligned and focused coincident with the slit illumination of a slit lamp.
• Figure I is provided as an exemplary embodiment and that other components may be added.
• the PDT laser system 100 may be constructed as a stand-alone PDT device with proper casings, removably attachable to a slit lamp microscope, or permanently attached to a slit lamp microscope,
• FIGS illustrates the fully assembled internal components of PDT laser 200 having a laser head 202, a heat sink 20 , a heat pipe 206, a fin array 20 ⁇ , a fiber optic cable 2 ⁇ . aa expander 212, a diverger 214, a collimator (not shown), an aperture wheel 218, a lens assembly 220, a partially reflective mirror 222, and a tonometer post 234.
• PDT laser 200 comprises the elements of PDT laser 100 discussed above with respect to Figure 1,
• FIG. 6 illustrates a modular block diagram of exemplary PDT laser in accordance with an embodiment of the invention.
• PDT laser housing 336 houses a laser head 302.
• the laser head 302 generates coherent light having a narrow bandwidth of ⁇ /- 3mm s a central wavelength of 689 nm, and light that supports a flnence rate of 0 to 600 mW/cm 2 light pins a eollinear aiming beam.
• the light from the laser head 302 is provided to the mode scrambler 338,
• the mode scrambler 338 may be a fiber optic cable or any mode scrambler known in the art.
• the optical modes that occur when a laser beam is transmitted by a multi-mode fiber optic are scrambled in the mode scrambler 338 to generate a circular beam with a top hat intensity profile.
• the laser head 302 may be a laser diode that combines the laser treatment beam and the aiming beam so that their laser outputs are optically eollinear with regard to the mode scrambler 33 ⁇ .
• the light output 340 from the mode scrambler 338 has a top hat intensity profile that propagates to the beam expander/'teiescope/collimaior 342.
• the top hat intensity profile is desirable because it provides a very uniform optical f!uenee rate (mW/cm 2 ) across the laser beam cross-sectional area to provide uniform activation of a photosensitizer across the area of tissue being treated.
• the laser beam from the mode scrambler 338 is expanded from 400 microns to 12 mm in diameter.
• expander/telescope/collinraior 342 pass eoiiimated light having a 12 mm diameter to the spot size selector 344,
• the spot size selector 344 may be machined with a plurality of spot size holes.
• the spot size selector 344 may be manually rotated so that one spot size is selected at a time.
• the hole intersects with the expanded laser beam and the laser light is transmitted through the hole onto projection optics 346.
• spot sizes in the range of 1.0 mm to 6.4 mm may be produced on the retix3 ⁇ 4a to treat lesion diameters from 0 to 5.4 mm. It is understood that a varying range of spot sizes may be used as known in the art.
• the light passes through the spot size selector 344 to the projection optics 346 wherein the projection optics provide a magnification factor (M) of 0.78. It is understood that a varying range of M may be used as known in the art.
• M magnification factor
• the light is projected from the projection optics 346 to the eye 348 to excite a photosensitizing agent.
• Figssre 7(a) illustrates an exemplary PDT laser system 400 having housing 436 and a tonometer post 434,
• the housing 436 has a displ y 450 that can display various treatment and laser parameters,
• the display 450 shows the therapeutic count down time: 83 seconds to 0,
• Figure 7(b) illustrates a profile view of an exemplary embodiment of the PDT laser system 400.
• Figure ⁇ illustrates a side view of an exemplary PDT laser system 500.
• a tonometer post 534 is provided on the outside of the housing 536.
• a laser head 502 generates a treatment and an aiming beam that is propagated through a fiber optic cable 510.
• the fiber optic cable 510 scrambles the modes,
• a beam expander/telescope/collimator 542 expands and collimates the light.
• An aperture wheel 518 selects an aperture size from the light from the
• the light from the aperture wheel 518 is propagated through a lens assembly (not shown) onto the partially reflected mirror to an eye (not shown). Heat is dissipated from the laser head 502 through the heat sink 504, heat pipe 506, and the fin array 508
• Figures 9, 10, and II illustrate exemplary optical configurations to provide a coincident aiming and laser beam.
• Figure 9 illustrates a beam splitter 652 thai combines a 689 arn therapy laser 654 and an aiming laser 6S& to a tissue target 658.
• Figure 10 illustrates a 6 " 89 nm therapy laser 754 and an aiming laser 756 thai are combined in a split fiber 76 .
• the split fiber 760 delivers the two beams to an optical system 762 having fora * lenses that propagates the light to the tissue target 758.
• Figure 11 illustrates a laser head 802 that generates a 689 nm therapy laser 854 and an aiming laser 856 that is propagated through a fiber optic cable to a tissue target 858. It is understood that the therapy or aiming laser beams (654, 754, and 854) described herein may be of any desired wavelength as known in the art.
• optical system 762 may be configured as described in previous embodiments or in any other method known in the art. It is further understood that the optical system 762 may have any number of lenses. It is understood that the systems and methods described herein to provide coincident aiming and treatment beams are merely exemplary and that any method known in the art may be utilized to provide coincident treatment and aiming beams.
• Figure 12 illustrates an exemplary user interface 900 that enables an operator—such as a physician, an ophthalmologist, a clinician, etc.— to setup a laser and perform therapy therewith, such as the lasers described herein.
• User interface 900 includes a display 902, a contact lens selector 904, a fluence rate selector 906, an aiming beam intensity selector 908, an emergency stop 910, a laser state selector 912, a spot size selector 914, and a key switch 916.
• display 902 is a two digit display thai displays a treatment countdown, provides feedback when the fluence rate is changed and displays error codes when required.
• the display may provide a countdown from 83 seconds when the laser is fired and, in some embodiments, the countdown cannot be altered except by restarting the laser system.
• Contact lens selector 904 may provide for toggling between available contact lens magnifications. For example, contact lens selector 904 may toggle between a 1.06X contact lens magnification (corresponding to a Volk Area Centralis contact lens or equivalent) and a 1.47X contact lens magnification (corresponding to a Mainster Wide Field contact lens or equivalent).
• Figures 13 and 14 illustrate some exemplary combinations of aperture size, spot size, and system magnification, in accordance with one embodiment of the invention. It will be understood by one of ordinary skill in the art that other combinations of spot sizes, system magnification, and apertures sizes could be equivalently used without deviating from the scope of the invention.
• fluence rate selector 906 allows the physician to select the desired fluence rate. When pressed while the laser is in setup mode, this button cycles the system through fluence rates of 600, 450, 300 or 150 mW/cm 2 . When the fluence rate is changed, the display will read 60, 45, 30 or 15, signifying 600, 450, 300 or 150 mW/cm 2 . When a
• a green LED shows beside the fluence rate selector.
• a red LED shows beside the fluence rate selector.
• aiming beam intensity selector 908 allows for continuous adjustment of the aiming beam from a minimum of OmW to a maximum of ⁇ lmW output.
• emergency stop 910 is a latching switch that will immediately disable power to the entire unit. A restart of the system will occur when the switch is "unlatched" and it will return to default settings.
• Laser state selector 912 may be adjusted to one of a ready state or a stand-by state. In both states the aiming beam is on. However, only in the ready state can the treatment beam be activated. When the laser is in "ready” mode a green LED shows beside the laser state selector. When the laser is in "standby” mode a red LED shows beside the laser state selector. [0087] According to one embodiment, spot size selector 914 is rotated to select the laser beam spot size.
• Key switch 916 may be a main power switch. When this key switch turned to the "on” position, the iaser powers up and the aiming beam is enabled. Whenever the ke is turned on, the system defaults to standard parameters of 600mW/cxn 2 s 83 second treatment timing, and 1 MX contact lens magnification, if required, the key can be removed from the switch when the system is in the "off 55 mode providing a simple way to control access to the laser system,
• the laser system may include other components, such as a foot switch and other controls and indicators.
• a foot switch may activate the treatment . beam when the laser is in "ready" mode. If the foot switch is released, the treatment beam is deactivated. If the treatment beam is interrupted during use by releasing the foot switch, the 83 second countdown will stop. If the foot switch is activated again without first shutting down the laser system, the countdown will resume from where it left off.
• Other controls may include a remote interlock connector that prevents operation of the treatment beam when the terminals of the connector are not electrically joined and an audible signal to indicate that the treatment beam is being fired.
• FIG. 15 illustrates an exemplary process flow 1000 carried out by software or other circuitry to execute steps for performing a laser-based therapy treatment, such as the treatments described herein.
• Process flow 1000 includes a therapy mode process 1002, a laser energized process 1004, a standby mode process 1006, a set default parameters process 1008, an aiming laser process 1010, and a setup mode process 1012.
• Each process in process flow 1000 includes arrows indicating an event or condition required to exit the process, an unconditional exit from a process, variables, and launches of parallel processes.
• the following exemplary method of system setup may be performed in conjunction with process flow 1000 above: (1) attach the laser unit to the slit lamp (SL) and align the SL observation system and illumination system, (2) turn laser unit power on using key switch, (3) allow the laser unit to self-test for approximately 15 seconds, (4) place the focusing post in the SL and bring it into focus while looking through the SL binoculars and having a narrow slit beam illumination, and (5) adjust the kser unit's lever and focusing knob, to ensure that the laser is aligned id focused at the same location as the slh beam,
• a latching emergency stop switch can immediately disable power to the entire unit;
• the control unit monitors the therapeutic, laser during activation, ensuring that the wavelength and power levels remain within the set parameters during treatment
• a watchdog feature ensures that, in case of failure of the control unit, the system will be shut down.
• maximum output of the laser is set in the circuit design, preventing excessive laser output in the case of simultaneous control unit and watchdog failure.
• a door interlock is provided that prevents use of the treatment beam if the operating room door is opened.
• a bar code scanner is added to a laser system to allow clinicians to quickly setup the system to correspond to the treatment parameters of one or more photoaetivating drags.
• a vial of a photoactive drug such as Visudyne®, for example
• the bar coding system incorporates a radio frequency identification system (" F!D") that gathers information from a RFID tag ort the vial.
• F!D radio frequency identification system
• the laser system may he preprogrammed with the identified photoactive drug's tas&tment parameters. In those embodiments, simply identifying the drug may be sufficient.
• the bar code or RFID tag may include other information such as the exact treatment parameters, expiration date of the drug, etc.
• the laser system may automatically alter the beam wavelength, fluence rate, power, duration of treatment, etc. accordingly.
• the laser system may require additional physical changes to correspond to a particular photosensitive drag, such as replacing the partially reflective mirror.
• the bar coding system and associated circuitry are stored in the laser housing.
• the bar coding system may be housed separately.
• Some further embodiments may include an approval system on the laser system that requests user con&mation before adjusting the laser system treatment parameters.
• the laser system is configured to read treatment parameters of all PDT compounds.
• the bar coding system is configured to read treatment parameters from one or more of a vial, a box, a reference book, and a electronic dispiay.
• Such electronic displays can be a smart phone or computer or any other electronic display and the information may be gathered from an email, a PDT compound manufacturer's website, or a database, for example.
• FIGS 16(a) and 16(b) illustrate an exemplary PDT laser 1102 according to an embodiment of the invention, mounted on a siit lamp 1104, with a mannequin's head 1106 at the position of the patient's head, PDT laser 1102 may comprise any of the PDT laser's described herein.
• the siit lamp 1104 may comprise any slit lamp which has structure to receive exemplary PDT laser 1102, f ⁇ 097] '
• Patient I is treated with a regimen in which they are admktistered 6 mg M 2 (of body surface area) of verteporfin in a commercially available li osomal intravenous composition obtainable torn QLT PhotoThemp tics, Vancouver, BC, assignee of the present application.
• Administration is intravenous. Thirty minutes after the start of infusion, the patient is administered a laser light having a wavelength of about 689 nm at 150- 600 mW/m 2 .
• Patient ⁇ is administered 6 mg/M 2 of verteporfln in the liposomal formulation, intravenously as with Patient I, but the laser light begins 20 minutes after the start of infusion.
• Patient III is subject to a regime identical to Patient I except 12 mg/M 2 of verteporfln is adrriinistered.
• an ocular lens such as Mainster, Volk Area Centralis, or any other indirect image lens known in the art may be utilized to aid in PDT or other treatments. These ocular lenses are required to focus the laser on the back of the retina. Without the ocular lenses the fundus cannot be visualized and the laser beam cannot be focused to the expected area on the patient's retina. It is further understood that any indirect (real) image contact lens may be utilized for PDT.
• the invention is not limited to PDT and may be configured to be utilized in other photocoagulation or non-thermal procedures (e.g., transpupillary thermotherapy). It is further understood that the invention may be utilized for the treatment of central serous chorioretinopathy (CSC) or polypoidal chorodial vasculopathy (PCV), subfoveal occult or classical) coroidal neovasculization (CNV), age-related macular degeneration (AMD). It also understood that principles of embodiments of the invention could be expanded to include thermal treatments.
• CSC central serous chorioretinopathy
• PCV polypoidal chorodial vasculopathy
• CNV subfoveal occult or classical) coroidal neovasculization
• AMD age-related macular degeneration
• the invention is not restricted to the illiistraled example architectures or configurations, but can be implemented using a variety of alternative architectures and conf gurations, Additionally, although the invention is described above in terms of various exemplary embodiments and implementations, it should be understood thai the various features andfunctionality described in one or more of the individual embodiments are not limited in their applicability to the particular embodiment with which they are described, but instead can be applied, alone or in some combination, to one or more of the other embodiments of the invention, whether or not such embodiments are described and whether or not such features are presented as being a part of a described embodiment. Thus the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments.

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