Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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METHOD FOR ALTERATION OF IRIS PIGMENT
CROSS-REFERENCE TO RELATED APPLICATION
The present Application claims the benefit of International Application
PCT/USOl/03569, filed February 2, 2001, entitled "Method for Alteration of
Iris Pigment,"
and is a continuation in part of United States patent application 09/776,345,
filed February 2,
2001, entitled "Method for Alteration of Iris Pigmentation," the contents of
which are
incorporated herein by reference in their entirety.
BACKGROUND
Iris color in humans varies widely between ethnic groups and between
individuals.
Iris color of a normal human is dependent on the presence and density of
colored pigment in
pigment cells in the iris. The colored pigment exists in more than one form,
for example, the
brown pigment eumelanin and the yellow pigment pheomelanin. Iris pigment
epithelial cells
containing the pigment eumelanin are present in both the anterior layer of the
iris and in the
deeper superficial stroma of the iris, while iris pigment epithelial cells
containing the pigment
pheomelanin are primarily present in the superficial stroma of the iris.
A complete lack of iris pigment results in a pink color due to the coloration
of
vascular components of the iris stroma. Very low pigment density causes the
scatter of white
light passing through the iris and is as blue, a process similar to the
scatter in the atmosphere
resulting in a blue sky. The remaining iris colors result from the increasing
density of one or
more of the forms of iris pigment.
Iris color plays and has played a significant social function as an attribute
of beauty.
In recent years, alteration of some types of iris color has become possible
through the use of
colored contact lenses. Such colored contact lenses can have a prescriptive
optical power, or
can be optically neutral such that the lenses serves a cosmetic function only.
There are several disadvantages associated with the use of colored contact
lenses for
cosmetic purposes. First, the lenses have the same potential complications of
use as contact
lenses with prescriptive optical powers, including allergic reactions to the
lens material and
infections from improper handling. Further, contact lenses cannot be tolerated
by some
potential users due to the discomfort. Additionally, colored contact lenses
require a degree of
dexterity to insert and remove that is not possessed by all potential users.
Further, permanent
changes in iris color cannot be achieved through the use of colored contact
lenses.
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Another method for altering iris color involves the use of colored lens
implanted
anterior to the iris. Such implants require an invasive procedure to place the
lens in position.
Because of the potential complication of an invasive procedure and of leaving
a foreign body
within the eye, the implantation of color lenses has not become a widely
adopted procedure.
Therefore, there remains a need for a method to alter iris pigment in a human
which
does not require colored contact lenses or implanted lenses. Additionally,
there remains a
need for a method to alter iris pigment in a human which can permanently alter
iris color.
SUMMARY
According to one embodiment of the present invention, there is provided a
method for
altering iris pigment in a human or animal, thereby altering iris color of a
first iris from a
first iris color to a second iris color. The method comprises, first,
selecting one or more than
one laser capable of generating one or more than one laser beam that will
remove
substantially similar amounts of iris pigment of at least two different iris
pigment colors from
the first iris, and then applying the one or more than one laser beam to the
first iris of a first
iris color to remove the iris pigment. The removal of the iris pigment causes
an alteration in
the color of the first iris from the first iris color to the second iris
color. The second iris
color is substantially the same hue as the first iris color but is less
saturated than the first iris
color, or the second iris color is both a different hue and less saturated
than the first iris
color.
In one embodiment, the human or animal is a human patient, and the method
further
comprises consulting with the patient to determine the second iris color
before applying the
one or more than one laser beam. In a preferred embodiment, the method further
comprises
repeating the selecting and applying steps at least one day after applying the
one or more than
one laser beam. In another preferred embodiment, the method further comprises
repeating
the selecting and applying steps at after a time between about 1 day and about
2 years after
applying the one or more than one laser beam. In another preferred embodiment,
the method
further comprises repeating the selecting and applying steps at least one day
after a time
between about 1 week and about 1 month after applying the one or more than one
laser beam.
In one embodiment, the second iris color does not naturally occur in a human
iris. In
another embodiment, the method further comprises creating an opening in the
cornea of the
human or animal before applying the one or more than one laser beam, and then
applying the
one or more than one laser beam through the opening.
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In one embodiment, the one or more than one laser selected is a pulse dye
laser. In
another embodiment, the one or more than one laser beam generated has a
wavelength of
between about 300 nm and about 900 nm.
In a preferred embodiment, the method further comprises altering iris pigment
in the
human or animal, thereby altering iris color of a second iris from a third
iris color to a fourth
iris color. The method comprises selecting one or more than one laser capable
of generating
one or more than one laser beam that will remove iris pigment from the second
iris, and then,
applying the one or more than one laser beam to the second iris of the third
iris color to
remove iris pigment. The removal of the iris pigment of the second selected
color causes an
alteration in the color of the second iris from the third iris color to the
fourth iris color. In a
particularly preferred embodiment, the second iris color is substantially same
as the fourth
iris color. In another particularly preferred embodiment, the second iris
color is substantially
different than the fourth iris color.
DESCRIPTION
According to one embodiment of the present invention, there is provided a
method for
altering iris pigment in a human, and thereby altering iris color from a first
iris color to a
second iris color. In one embodiment, the method comprises selecting one or
more than one
laser capable of generating one or more than one laser beam that will
selectively remove iris
pigment substantially of only a first pigment color, or that will remove iris
pigment
substantially uniformly of all iris pigment colors to decrease the overall
density of all colors
of iris pigment, or that will remove iris pigment of a first pigment color and
a second
pigment color while removing more iris pigment of the first pigment color than
iris pigment
of the second pigment color. Next, the one or more than one laser beam is
applied to an iris
of a first iris color to remove iris pigment. The removal of iris pigment
causes an alteration
in the color of the iris from the first iris color to the second iris color,
where the second iris
color is a different hue than the first iris color, or is a different
saturation than the first iris
color or is both a different hue and a different saturation than the first
iris color. The method
will now be explained in greater detail.
According to another embodiment of the present invention, there is provided a
method
for altering the iris pigment in the iris of an animal or a human to change
the color of the iris
from a first iris color to a second iris color. The method of the present
invention is
performed as follows. First, the human patient or animal is examined and, if a
human
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patient, a determination is made in consultation with the human patient as to
the patient's
desired iris color. Next, a determination is made as to whether the patient's
desired iris color
can be obtained using the method of the present invention by virtue of laser
alteration of the
patient's existing iris pigment as will be understood by those in the art with
reference to this
disclosure. For example, if the patient has brown irises and desires to have
green irises, then
laser alteration of the patient's iris pigment using the present method can
alter the patient's
irises to green. Similarly, if the patient has brown irises and desires to
less saturated brown
irises, then laser alteration of the patient's iris pigment using the present
method can alter the
patient's irises to less saturated brown irises. Further, if the patient has
brown irises and
desires to have green irises that are also less saturated, then laser
alteration of the patient's
iris pigment using the present method can alter the patient's irises to less
saturated green
irises. If, however, the patient has blue irises and desires to have brown
irises, then laser
alteration of the patient's iris pigment using the present method cannot alter
the patient's
irises to brown, as will be understood by those in the art with reference to
this disclosure.
Next, the method comprises selecting one or more than one laser capable of
generating one or more than one laser beam. Depending on the first iris color
and the
desired second iris color, as will be understood by those in the art with
reference to this
disclosure, the one or more than one Iaser beam is selected that will either
selectively remove
iris pigment substantially of only a first selected pigment color, or that
will remove iris
pigment substantially uniformly of all iris pigment colors to decrease the
overall density all
colors of iris pigment, or that will remove iris pigment of a first pigment
color and a second
pigment color while removing more iris pigment of the first pigment color than
iris pigment
of the second pigment color.
For example, if the second iris color is the substantially the same hue but
less
saturated than the first iris color, than the one or more than one laser is
selected that will
remove iris pigment substantially uniformly of all iris pigment colors to
decrease the overall
density of all colors of iris pigment. Alternately, if the second iris color
is a different hue
than the first iris color, than the one or more than one laser is selected
that will selectively
remove iris pigment substantially of only a first selected pigment color.
Similarly, if the
second iris color is both a different hue and less saturated than the first
iris color, than the
one or more than one laser is selected that will remove iris pigment of a
first pigment color
and a second pigment color while removing more iris pigment of the first
pigment color than
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iris pigment of the second pigment color, depending on the first iris color
and the desired
second iris color, as will be understood by those in the art with reference to
this disclosure.
Next, the one or more than one laser beam is applied to the iris of the first
iris color
at a sufficient intensity and for a sufficient time to remove iris pigment,
where the removal of
the iris pigment causes an alteration in the color of the iris from the first
iris color to the
second iris color. If more than one laser beam is used, the laser beams can be
applied
sequentially or simultaneously. The second iris color is a different hue than
the first iris
color, or is substantially the same hue as the first iris color but less
saturated than the first iris
color, or is both a different hue and less saturated than the first iris
color. Further, it is
possible using methods according to the present invention to alter iris
pigment of a patient to
result in an iris color which is not naturally occurring, such as violet, or
to alter iris pigment
differently between two eyes of a patient to result in the patient having
irises of different
colors by differentially treating each iris of a patient according to one
method of the present
invention or by treating only one iris of the patient according to the present
invention.
Preferably, the intensity of the laser beam is set to a level that minimizes
the damage
to any ocular tissue while still allowing satisfactory removal of the required
iris pigment.
The method of the present invention can further include creating an opening in
the cornea of
the human before applying the one or more than one laser beam, and then
applying the one or
more than one laser beam through the opening in order to minimize damage to
the anterior
ocular structures. If necessary, a temporary contact lens can be applied to
reduce post-
procedure discomfort.
Additionally, the method of the present invention can be repeated at a time
spaced
apart from the original application of the one or more than one laser, in
order to further alter
the iris pigment, after allowing the iris and associated tissue to heal from
the original
application. For example, the method can be repeated at least one day after
applying the one
or more than one laser beam to the iris. In a preferred embodiment, the method
is repeated
at a time between about 1 day and about 2 years after applying the one or more
than one laser
beam to the iris. In a particularly preferred embodiment, the method is
repeated at a time
between about 1 week and about 1 month after applying the one or more than one
laser beam
to the iris.
The use of lasers to remove iris pigment is advantageous because specific
lasers can
be selected which create laser beams which are selectively absorbed by iris
pigment of
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specific colors. This property allows the selection of lasers to selectively
destroy iris pigment
of specific colors while not destroying iris pigment of other colors. For
example, the one or
more than one laser beam generated could be selected to substantially remove
only eumelanin
or substantially remove only pheomelanin. Alternately, one or more than one
laser beam can
be selected to remove iris pigment substantially uniformly of all iris pigment
colors to
decrease the overall density all colors of iris pigment. Additionally, the one
or more than
one laser beam can be selected to remove iris pigment of a first pigment color
and a second
pigment color while removing more iris pigment of the first pigment color than
iris pigment
of the second pigment color.
In a preferred embodiment, the one or more than one laser selected is a pulse
dye
lasers because the wavelength of the laser beam is determined by the color of
the material
through which the laser beams pass. This advantageously increases the
specificity of iris
pigment destruction by the laser beams by selecting appropriate dyes.
Moreover, the
intensity of the laser beams can be adjusted to minimize damage to ocular
tissue and iris
pigments that are not specifically targeted. In another preferred embodiment,
the one or
more than one laser is a pulse dye laser and the wavelength generated by the
one or more
than one laser is between about 300 nm and about 900 nm. For example, suitable
lasers
includes the Due-220, DUO-221, and the DUO-210 models, as well as the DYE 120,
the
DYE 121, and the DYE 110 models ( Laser Science, Inc., Franklin, MA US).
In another preferred embodiment, the one or more than one laser selected is a
modified excimer laser which permits the operator to alter the nature and
quantity of the
material through which the laser beam passes. Preferably, the one or more than
one excimer
laser will generate a wavelength of between about 100 nm and 250 nm. For
example, the
ArF excimer laser used in ophthalmic photoablation produces a beam of
ultraviolet light with
a wavelength of 193 nm. The ArF excimer laser beam passes though a specified
quantity of
argon fluoride, and both the material and its quantity can be modified to
achieve.the desired
wavelength. Additionally, LaserSight Technologies, Inc. (Winter Park, FL US)
has devised
two solid state lasers: the LaserHarmonic-1 and LaserHarmonic-2. The
LaserHarmonic-1 is
flash lamp pumped and employs the fifth harmonic of a Nd:Yag at 213 nm. The
LaserHarmonic-2 is a diode pumped fifth harmonic Nd:YLF laser at 209 nm. While
a pulse
dye laser or an excimer laser are preferred, other lasers can be used in the
present method..
EXAMPLE I
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One method of the present invention is performed as follows. An adult male
patient is
selected who desires to change his brown iris color to green. He is found in
satisfactory
general and ocular health. After being counseled regarding the procedure and
being
prepared, a suitable laser is selected and is applied to each iris through the
patient's intact
corneas to remove pigment present in his irises until the remaining iris
pigment is to render
his irises green.
Although the present invention has been discussed in considerable detail with
reference to certain preferred embodiments, other embodiments are possible.
Therefore, the
scope of the appended claims should not be limited to the description of
preferred
embodiments contained in this disclosure.
