USING INTENSE PULSED LIGHT TO LIGHTEN EYE COLOR

Abstract

The present invention relates to a device for permanently changing the color of the iris, such as from brown to blue. The invention is a system that includes a slit lamp microscope, a source of intense pulsed light (IPL), optical tracking and measuring systems, and a device that prevents the application of light to the pupil. The IPL provides a simultaneous application of a range of wavelengths, rather than the single wavelength typically applied by lasers. In a preferred embodiment, the IPL is applied as annular ring, striking only the iris and not the pupil or the sclera. Air or liquid cooling can be used to prevent the eye from overheating.

Claims

1. A system for changing the color of the iris of an eye, comprising: a slit lamp microscope; a source of IPL for application to the iris and sufficient to cause the iris to become lighter in color, the IPL having a defined range of wavelengths; a measuring and tracking system to control the application of the IPL to the iris; and, means for preventing application of IPL to the pupil of the eye.

2. The invention of claim 1, wherein the means for preventing application includes at least one of an opaque cover of the pupil and a control of the measuring and tracking system that prevents application of the IPL to ocular structures other than the iris.

3. The invention of claim 2, wherein the control of the measuring and tracking system applies a generally annular-shaped ring of light only to the iris.

4. The invention of claim 2, wherein the control of the measuring and tracking system applies light in at least one of a triangle, rectangle, and a plurality of overlapping circles.

5. The invention of claim 2, wherein the IPL wavelengths are in a range of 250 to 700 nanometers.

6. The invention of claim 2, wherein the IPL wavelengths are in a range of 700 to 1,400 nanometers.

7. The invention of claim 2, further comprising an eye coolant applicator for applying at least one of an air and a liquid coolant.

8. The invention of claim 4, wherein the control of the measuring and tracking system applies a generally annular-shaped ring of light only to the iris.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Below is a detailed description that refers to the novel aspects of the invention, including equivalents known by those of skill in the art, and in that context refers to the following figures.

[0017] FIG. 1 depicts an eye, including anterior aspects such as the cornea, the pupil, the iris, the lens, and the sclera.

[0018] FIG. 2 is a general depiction of a prior art slit lamp microscope.

[0019] FIG. 3 is schematic drawing of one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The purpose of the invention 10 is to remove pigment from the iris 15 of eye 12, without exposing pupil 14 to any harmful light. See FIG. 1 for a general depiction of the eye. One embodiment of the invention 10 includes a slit lamp microscope 20 that uses IPL 32 to remove iris pigment from a patient's eye PE. See FIG. 3. The IPL is applied multichromatically, as a diffuse light source, to heat the melanin. The preferable spectrum runs between about 500 and 1400 nm, although wavelengths as low as 250 nm have been used. Wavelengths can be adjusted lower or higher to account for variations in the melanin. Filters can be used to control the minimum and maximum wavelengths that are used in a single pulse or in multiple pulses. Depending on the nature of the patient's eye, and the amount of IPL used, eye color can be changed from dark (e.g., brown) to light (e.g., blue, green, hazel). It should be noted that this invention would not perform the reverse function, i.e., creating melanin to darken the eye.

[0021] Slit lamp microscope 20 includes several parts, such as binocular or monocular viewing for the operator's eyes OE, slit lamp 36, and slit plate 37 with slit 38, and joystick 52. Too much movement on the part of the patient might lead to an undesirable result, so for a procedure such as exposing the iris to IPL the patient's head ideally should be mechanically secured against movement, whereas a simple examination with a slit lamp microscope usually requires the patient to place his chin and forehead against the frame and avoid moving. More effective prevention of head movement can be accomplished by strapping or otherwise securing the patient's head to the frame that makes up the chin support and head support (see headrest 120, FIG. 2, strap not shown). Light and power source 30 provides power to slit lamp 36 through wire 35. Lamp 36 generates illuminating light 31, which travels to patient eye PE and reflects back to the operator's eyes OE looking through microscope 20. A joystick 52 controls the direction of the illuminating light 31 onto patient eye PE. As noted above, the slit lamp microscope may have other control features as well, which are known to those of skill in the art.

[0022] Light and power source 30 also contains the source that produces IPL 32, which reflects off mirror 34 onto waveform combining mirror 39, combining the illuminating light 31 with IPL 32. Light 31, 32 is reflected through prism mirror 26 to patient eye PE. Obviously the slit lamp 36 can be operated independently of IPL 32, so that the operator can examine the eye without applying IPL 32. Similarly, invention 10 contemplates using slit lamp 36 and IPL 32 concurrently, so that the operator can view the iris while IPL is applied during the treatment. While the operator's eyes OE are viewing the patient eye PE through microscope 20, beam splitter 22 creates two beams, each containing the illuminating light 31 and the IPL 32 reflected by the patient's eye PE. One beam goes to microscope 20 for viewing by the operator's eyes OE. It should be noted that the oculars of the microscope contain filters to prevent IPL treating the operator's irises and the operator would be required to wear protective eyewear for this purpose as well for additional operator protection. The other beam is diverted to the tracking and measuring systems 40 to provide continual feedback and control of the IPL application. Tracking and measuring systems 40 may also use a laser (not shown).

[0023] Eye tracking and measuring systems 40 control the depth, wavelength, timing, and spacing of each IPL application. Tracking and measuring the eye involve complex hardware, software, and optical systems that are known to those in the art of optical equipment design. In this simplified view, as shown in FIG. 3, trackers 41, 42 use infrared measurements as one embodiment of eye tracking to track the movement of patient eye PE. This information is fed back to the main tracking and measuring system 40 and to mirror control and IPL aiming system 50, which in turn aims IPL 32 through the control of mirrors 26, 39 and to patient eye PE. These mirrors are intended to generally represent the more complex and detailed aspects of aiming narrow light beams that are known to those of ordinary skill in the art. They can, for example, work with or independently of joystick 52. The type and degree of viewing control may be chosen by one of ordinary skill whose is designing the device.

[0024] Other necessary aspects of the invention are known to those of ordinary skill in the art, and thus need not be described here in detail. For example, virtually all commercially available lasers used in refractive surgery are associated with some form of eye-tracking system that can account for movement of both the eye and the head. Examples of prior art tracking systems include U.S. Pat. No. 6,280,436 to Freeman et al and US2002/0051116 to Van Saarloos et al. A tracker consists of a reception system and a repositioning system that maintains the laser within a specific tracking range. A passive system determines an interruption in the emission of pulses because of eye movements that exceed the tracking range, thus stopping the laser or other light source. In contrast, an active tracking system follows the ocular movements by centering the treatment on the exact position programmed at the start of surgery. Some tracking systems contain elements of both passive and active tracking.

[0025] In the preferred embodiment of the invention, the tracking system is combined with a measuring system that determines a variety of parameters necessary for the color change procedure, such as the geometry of the various parts of the eye including the cornea, the pupil, and the iris. Those of skill in the art are familiar with such systems, including aspects such as programming functions, hardware, software, and algorithms. Likewise, programmable and built-in features would permit the use of lightwave filters, IPL pulse length and spacing, the number of pulses, and other necessary features.

[0026] Cooling devices could also be added to prevent the iris from overheating. Fans or air nozzles could blow air directed toward the eye. Likewise, a liquid coolant could be sprayed or misted directly onto the eye. Such devices would be located near the patient's head. If the invention were constructed similar to the slit lamp microscope depicted in FIG. 2, one could attach cooling devices to headrest 120 or on separate structures located nearby.

[0027] Although the inventor has described what he considers the best mode of carrying out the invention, it will be apparent to those skilled in the art that modifications, variations, and equivalents can be made without departing from the scope of the invention as detailed in the claims below. For example, if it is desirable to heat chromophores other than melanin, like water, other wavelength ranges of IPL could be used. Those of skill in the art will appreciate that the physical form of the invention can vary. A single device can incorporate all of the elements of the invention. Alternatively, the invention can be a system of two or more separate elements linked together. Thus, one might refer to the invention as a device or as a system. A small example is the application of light. As described above, illumination light 31 and IPL 32 are preferably delivered together through combining mirror 39 and prism mirror 26. This physical arrangement, however, is not a requirement of the invention.