U.S. patent application number 10/934654 was filed with the patent office on 2005-04-28 for method and apparatus for alignment of intracorneal inlay.
Invention is credited to Peyman, Gholman A..
Application Number | 20050090895 10/934654 |
Document ID | / |
Family ID | 25532728 |
Filed Date | 2005-04-28 |
United States Patent
Application |
20050090895 |
Kind Code |
A1 |
Peyman, Gholman A. |
April 28, 2005 |
Method and apparatus for alignment of intracorneal inlay
Abstract
A method of correcting refractive error in an eye, comprising
the steps of marking at least one axis on the surface of the
cornea. A portion of the cornea is then separated, forming a first
anterior facing surface and a second posterior facing surface. An
inlay having at least one axis indicated on the surface thereof is
positioned between the first and second surfaces, and the at least
one axis on the inlay is aligned with the at least one axis on the
surface of the cornea. This results in precise positioning and
orientation of the inlay and thus correction of astigmatic error in
the cornea.
Inventors: |
Peyman, Gholman A.; (New
Orleans, LA) |
Correspondence
Address: |
BELL, BOYD, & LLOYD LLC
P. O. BOX 1135
CHICAGO
IL
60690-1135
US
|
Family ID: |
25532728 |
Appl. No.: |
10/934654 |
Filed: |
September 3, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10934654 |
Sep 3, 2004 |
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09986775 |
Nov 9, 2001 |
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6786926 |
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Current U.S.
Class: |
623/5.11 ;
623/905 |
Current CPC
Class: |
A61F 9/0136 20130101;
A61F 9/013 20130101; A61F 2/1451 20150401; A61F 2/145 20130101;
Y10S 623/906 20130101 |
Class at
Publication: |
623/005.11 ;
623/905 |
International
Class: |
A61F 002/14 |
Claims
1. A method of aligning an intracorneal inlay relative to a cornea
for the purpose of correcting refractive error in an eye,
comprising the steps of marking at least one axis on the outer
surface of the cornea, separating a portion of the cornea, forming
a first anterior facing surface and a second posterior facing
surface, positioning an inlay having at least one axis indicated on
the surface thereof between the first and second surfaces, and
aligning the at least one axis on the inlay with the at least one
axis on the surface of the cornea.
2. A method according to claim 1, wherein the marking step includes
marking at least five axes on the outer surface of the cornea.
3. A method according to claim 2, wherein the marking step includes
marking the outer surface of the cornea with a marking tool having
at least five axes thereon.
4. A method according to claim 3, wherein the marking step includes
positioning the marking tool adjacent the outer surface of the
cornea and marking a line along each of the five axes of the
marking tool.
5. A method according to claims 1, wherein the separating step
includes separating a portion of the cornea to form a flap thereon,
the flap attached to the cornea at an outer peripheral area
thereof.
6. A method according to claim 5, further comprising the step of
pivoting the flap about the area attached to the cornea to expose
the first anterior facing surface of the cornea.
7. A method according to claim 6, wherein the positioning step
includes positioning an inlay having a removable, pliable sheet
overlying the inlay indicating the at least one axis.
8. A method according to claim 7, further comprising the steps of
marking the main optical axis of the eye on the outer surface of
the cornea prior to marking the at least one axis on the surface of
the cornea, marking the main optical axis of the eye on the first
anterior facing surface of the cornea, and marking the first
anterior facing surface of the cornea with at least five axes in
about the same orientation as the markings on the surface of the
cornea.
9. A method according to claim 8, further comprising the steps of
repositioning the flap over the inlay, aligning the markings on the
outer surface of the eye and the marking on the first anterior
facing surface with the marking on the removable, pliable sheet,
and removing the removable, pliable sheet overlying the inlay.
10. A method according to claim 9, wherein the positioning step
includes positioning an inlay adapted to correct astigmatic error
in the eye between the first and second surface.
11. A method according to claim 1, wherein the positioning step
includes positioning a ring shaped inlay between the first and
second surfaces.
12. A method according to claim 11, wherein the positioning step
includes positioning a ring shaped inlay having at least two
separable portions between the first and second surfaces.
13. A method according to claim 1, wherein the positioning step
includes positioning an inlay adapted to correct astigmatic error
in the eye between the first and second surface.
14. A method according to claim 1, wherein the positioning step
includes positioning the inlay between the first and second
surfaces using a holding tool.
15. A method of aligning an intracorneal inlay relative to a cornea
for the purpose of correcting refractive error in an eye,
comprising the steps of separating a portion of the cornea, forming
a first anterior facing surface and a second posterior facing
surface, marking at least one of the first and second surfaces with
a first axis, positioning an inlay having a second axis indicated
on the surface thereof between the first and second surfaces, and
aligning the second axis with the first axis.
16. A method according to claim 15, further comprising the step of
marking at least four additional axes on at least one of the first
and second surfaces of the cornea.
17. A method according to claim 16, wherein the marking step
includes marking at least one of the first and second surfaces of
the cornea with a marking tool having at least five axes
thereon.
18. A method according to claim 17, wherein the marking step
includes positioning the marking tool adjacent the first surface of
the cornea and marking a line along each of the five axes of the
marking tool.
19. A method according to claims 15, wherein the separating step
includes separating a portion of the cornea to form a flap thereon,
the flap attached to an area of the cornea at the circumference
thereof.
20. A method according to claim 19, further comprising the step of
pivoting the flap about the area attached to the cornea to expose
the first anterior facing surface of the cornea.
21. A method according to claim 20, wherein the positioning step
includes positioning an inlay having a removable, pliable sheet
overlying the inlay indicating the second axis between the first
and second surfaces.
22. A method according to claim 21, further comprising the steps of
marking the main optical axis of the eye on the external surface of
the cornea, marking the external surface of the cornea with a third
axis in about the same orientation as the markings on the first
anterior surface, and marking the main optical axis of the eye on
at least one of the first and second surfaces of the cornea prior
to marking the first axis on the at least one of the first and
second surfaces of the cornea.
23. A method according to claim 22, further comprising the steps of
repositioning the flap over the inlay, aligning the first axis and
the third axis with the second axis, and removing the pliable sheet
overlying the inlay.
24. A method according to claim 23, wherein the positioning step
includes positioning an inlay adapted to correct astigmatic error
in the eye between the first and second surfaces.
25. A method according to claim 15, wherein the positioning step
includes positioning a ring shaped inlay between the first and
second surfaces.
26. A method according to claim 25, wherein the positioning step
includes positioning a ring shaped inlay having at least two
separable portions between the first and second surfaces.
27. A method according to claim 15, wherein the positioning step
includes positioning an inlay adapted to correct astigmatic error
in the eye between the first and second surface.
28. (canceled)
29. (canceled)
30. (canceled)
31. (canceled)
32. (canceled)
33. A method positioning an inlay on the cornea to correct
refractive error in the cornea of the eye, the cornea having a
first corneal surface and a second corneal surface, the method
comprising the steps of positioning an inlay having a first surface
and a second surface on the first corneal surface, and positioning
a removable, pliable sheet of material directly adjacent the second
surface of the inlay, said sheet overlying and conforming to the
second surface of the inlay and having markings thereon for
accurately positioning the inlay on the first corneal surface.
34. A method according to claim 33, further comprising the steps of
separating a portion of the cornea to expose the first and second
corneal surfaces and form a flap; and marking at least one of the
first and second corneal surfaces with a first axis.
35. A method according to claim 34, further including the step of
aligning the markings on the removable, pliable sheet with the
first axis.
36. A method according to claim 35, further comprising the step of
removing the removable, pliable sheet.
37. A method according to claim 36, further comprising the step of
replacing the flap such that the second corneal surface is
immediately adjacent and overlying the second surface of the inlay.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method and apparatus for
correcting the astigmatic refractive, error in the cornea of the
eye. In particular, the cornea is modified by forming a flap in the
cornea and exposing a portion of the cornea underlying the flap.
The exposed portion is marked and an asymmetric inlay having a thin
removable, transparent sheet with markings indicated thereon is
positioned on the exposed portion of the cornea. The markings on
the cornea and those on the sheet are aligned to ensure proper
positioning of the asymmetric inlay.
BACKGROUND OF THE INVENTION
[0002] A normal emetropic eye includes a cornea, a lens and a
retina. The cornea and lens of a normal eye cooperatively focus
light entering the eye from a far point, i.e., infinity, onto the
retina. However, an eye can have a disorder known as ametropia,
which is the inability of the lens and cornea to focus the far
point correctly on the retina Typical types of ametropia are
myopia, hypermetropia or hyperopia, and astigmatism.
[0003] A myopic eye has either an axial length that is longer than
that of a normal emetropic eye, or a cornea or lens having a
refractive power stronger than that of the cornea and lens of an
emetropic eye. This stronger refractive power causes the far point
to be projected in front of the retina
[0004] Conversely, a hypermetropic or hyperopic eye has an axial
length shorter than that of a normal emetropic eye, or a lens or
cornea having a refractive power less than that of a lens and
cornea of an emetropic eye. This lesser refractive power causes the
far point to be focused behind the retina.
[0005] An eye suffering from astigmatism has a defect in the lens
or shape of the cornea. Therefore, an astigmatic eye is incapable
of sharply focusing images on the retina.
[0006] Optical methods are known which involve the placement of
lenses in front of the eye, for example, in the form of eyeglasses
or contact lenses, to correct vision disorders. A common method of
correcting myopia is to place a "minus" or concave lens in front of
the eye to decrease the refractive power of the cornea and lens. In
a similar manner, hypermetropic or hyperopic conditions can be
corrected to a certain degree by placing a "plus" or convex lens in
front of the eye to increase the refractive power of the cornea and
lens. Lenses having other shapes can be used to correct
astigmatism. The concave, convex or other shaped lenses are
typically configured in the form of glasses or contact lenses.
[0007] Although these optical methods can be used to correct vision
in eyes suffering from low myopia, or in eyes suffering from
hypermetropic, hyperopic or astigmatic conditions which are not
very severe, these methods are ineffective in correcting vision in
eyes suffering from severe forms of ametropia.
[0008] However, surgical techniques exist for correcting these more
severe forms of ametropia to a certain degree. For example, in a
technique known as myopic keratomileusis, a microkeratome is used
to cut away a portion of the front of the live cornea from the main
section of the live cornea. The cut portion of the cornea is frozen
and placed in a correlate where it is cut and reshaped. Altering
the shape of the cut portion of the cornea changes the refractive
power of this cut portion, which thus affects the location at which
light entering the cut portion of the cornea is focused. The
reshaped cut portion of the cornea is then thawed and reattached to
the main portion of the live cornea. Hence, it is intended that the
reshaped cornea will change the position at which the light
entering the eye through the cut portion is focused, so that
hopefully the light is focused directly on the retina, thus
remedying the ametropic condition.
[0009] The myopic keratomileusis technique is known to be effective
in curing myopic conditions within a high range. However, the
technique is impractical because it employs very complicated and
time consuming freezing, cutting and thawing processes.
[0010] Keratophakia is another known surgical technique for
correcting severe ametropic conditions of the eye by altering the
shape of the eye's cornea. In this technique an artificial, organic
or synthetic lens is implanted inside the cornea to thereby alter
the shape of the cornea and thus change its refractive power.
Accordingly, as with the myopic keratomileusis technique, it is
desirable that the shape of the cornea be altered to a degree that
allows light entering the eye to be focused correctly on the
retina.
[0011] However, the conventional lenses and methods for type of
correction are often impractical for correcting astigmatic error in
the eye. Since an irregular shaped cornea or eye generally causes
astigmatic error, to correct astigmatism an implanted lens must be
a specific asymmetrical shape that would negate the irregularity.
Often is difficult to properly position and maintain the lens in
the correct orientation relative to the cornea, thereby making the
procedure difficult and time consuming.
[0012] Examples of known techniques for modifying corneal
curvature, such as those discussed above, are described in U.S.
Pat. No. 4,994,058 to Raven et al., U.S. Pat. No. 4,718,418 to
L'Esperance, U.S. Pat. No. 5,336,261 to Barrett et al., and a
publication by Jose I. Barraquer, M.D. entitled "Keratomileusis and
Keratophakia in the Surgical Correction of Aphakia". The entire
contents of each of these patents are incorporated herein by
reference.
[0013] Surgical techniques involving the use of ultraviolet and
shorter wavelength lasers to modify the shape of the cornea also
are known. For example, excimer lasers, such as those described in
U.S. Pat. No. 4,840,175 to Peyman, which emit pulsed ultraviolet
radiation, can be used to decompose or photoablate tissue in the
live cornea so as to reshape the cornea.
[0014] Specifically, a laser surgical technique known as laser in
situ keratomileusis (LASIK) has been previously developed by the
present inventor. In this technique, apportion of the front of a
live cornea can be cut away in the form of a flap having a
thickness of about 160 microns. This cut portion is removed from
the live cornea to expose an inner surface of the cornea. A laser
beam is then directed onto the exposed inner surface to abate a
desired amount of the inner surface up to 150-180 microns deep. The
cut portion is then reattached over the ablated portion of the
cornea and assumes a shape conforming to that of the ablated
portion.
[0015] However, because only a certain amount of cornea can be
ablated without the remaining cornea becoming unstable or
experiencing outward bulging (eklasia), this technique is not
especially effective in correcting very high myopia or large
astigmatic error. That is, a typical live cornea is on average
about 500 microns thick. The laser ablation technique requires that
at least about 200 microns of the corneal stroma remain after the
ablation is completed so that instability and outward bulging does
not occur. Hence, this method typically cannot be effectively used
to correct high myopia or large astigmatic error, because, in order
to reshape the cornea to the degree necessary to alter its
refractive power to sufficiently correct the focusing of the eye,
too much of the cornea would need to be ablated.
[0016] Other techniques exist for correcting astigmatic error using
markings on a lens. However, these techniques generally only have a
mark or multiple marks on a portion of the lens. This type of
marking may indicate what direction the lens should be implanted in
the cornea; however, they generally do not do not indicate where on
the cornea they should be placed. For example, astigmatic
correction is a relatively precise procedure and the lens must be
placed both centrally on the cornea or at least in a predetermined
position and oriented radially in the correct position, to negate
the asymmetric shape of the cornea. The conventional procedures do
not allow the proper alignment of the cornea surface and the lens
implanted thereon. Therefore, existing procedures are inadequate to
correct astigmatic error. Furthermore, many of these procedures
have permanent markings on the lens, which may hinder the sight of
the patient.
[0017] Therefore, it is apparent that a need therefore exists for
improved methods for further modifying the cornea to better correct
ametropic conditions, and more specifically to correct astigmatic
error.
SUMMARY OF THE INVENTION
[0018] Accordingly, it is an object of the present invention to
provide a method for adjusting the shape of a live cornea to
correct high ametropic conditions.
[0019] Another object of the invention is to provide a method for
modifying the shape of a live cornea to correct astigmatic
conditions.
[0020] Yet another object of the present invention is to provide a
method for adjusting the shape of a live cornea to correct
astigmatic conditions by aligning the inlay with markings on the
cornea.
[0021] Still another object of the present invention is to provide
an intracorneal inlay having removable alignment markings
thereon.
[0022] Still yet another object of the present invention is to
provide an intracorneal inlay for correcting the refractive error
in the eye having a removable, pliable sheet with markings thereon
overlying at least a portion of the inlay to indicate the alignment
of the inlay.
[0023] Further still it is another object of the present invention
to provide an inlay for correcting the refractive error in the eye
that is positioned under a flap in the cornea and aligned with
markings on an exposed surface of the cornea.
[0024] The foregoing objects are basically attained by a method of
correcting refractive error in the cornea of an eye, comprising the
steps of marking at least one axis on the surface of the cornea,
separating a portion of the cornea, forming a first anterior facing
surface and a second posterior facing surface, positioning a inlay
having at least one axis indicated on the surface thereof between
the first and second surfaces, and aligning the at least one axis
on the inlay with the at least one axis on the surface of the
cornea.
[0025] The foregoing objects are further attained by an inlay for
correcting the refractive error in the cornea of the eye,
comprising a first surface for placement onto an exposed surface of
the cornea, a second surface opposite the first surface, and a
removable sheet of material overlying the second surface, the sheet
having markings thereon for accurately positioning the inlay on the
exposed surface of the cornea
[0026] Other objects, advantages, and salient features of the
present invention will become apparent to those skilled in the art
from the following detailed description, which, taken in
conjunction with the annexed drawings, discloses preferred
embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Referring to the drawings which form a part of this
disclosure:
[0028] FIG. 1 is an elevational front view of an eye with the
cornea marked along the main optical axis;
[0029] FIG. 2 is a plan top view of a marking device having 5 axes,
according to the present invention;
[0030] FIG. 3 is a side view in section of the marking device taken
along lines 3-3 of FIG. 2.
[0031] FIG. 4 is an elevational front view of the marking device of
FIG. 2 overlying the eye of FIG. 1;
[0032] FIG. 5 is an elevational front view of the eye of FIG. 4
after markings were applied thereto by the marking device of FIG.
3;
[0033] FIG. 6 is an elevational front view of the eye of FIG. 5
with a flap formed in the surface of the cornea;
[0034] FIG. 7 is an elevational front view of the eye of FIG. 6
with a device marking the main optical axis under the flap;
[0035] FIG. 8 is an elevational front view of the eye of FIG. 7
with the flap pivoted to expose a surface of the cornea and the
marking device of FIG. 3 adjacent thereto;
[0036] FIG. 9 is an elevational front view of the eye of FIG. 8
after markings are applied thereto by the marking device of FIG.
3;
[0037] FIG. 10 is plan top view of an inlay according to the
present invention with a pliable material overlying the inlay;
[0038] FIG. 11 is a side view in cross section taken along lines
11-11 of the inlay of FIG. 10;
[0039] FIG. 12 is a plan top view of a tool for holding the inlay
adjacent a corneal surface and positioning it thereon;
[0040] FIG. 13 is a side view on cross-section of the tool of FIG.
12 taken along lines 13-13;
[0041] FIG. 14 is a elevational front view of the eye of FIG. 9
with the inlay of FIG. 10 positioned on an exposed surface of the
cornea using the tool of FIG. 13;
[0042] FIG. 15 is a side view in cross-section of the eye of FIG.
14 taken along
[0043] FIG. 16 is a elevational front view of the eye of FIG. 15
with the flap repositioned, the inlay aligned and a pair of forceps
removing the pliable material from the surface of the inlay;
[0044] FIG. 17 is a side view in cross section of FIG. 16, taken
along lines 17-17;
[0045] FIG. 18 is a side view in section of the eye if FIG. 17
after the pliable material has been removed;
[0046] FIG. 19 is a plan top view of a ring shaped inlay suitable
for the present procedure;
[0047] FIG. 20 is a side cross sectional view of the inlay of FIG.
19 taken along lines 20-20;
[0048] FIG. 21 is a plan top view of a two-piece ring shaped inlay
suitable for the present procedure; and
[0049] FIG. 22 is a side cross sectional view of the inlay of FIG.
21 taken along lines 22-22.
DETAILED DESCRIPTION OF THE INVENTION
[0050] As shown in FIGS. 1-17, the refractive properties of the eye
can be modified or altered by placing markings 26 and 28 on both
the external or outer surface 14 of the cornea 12 of an eye 10 and
an internal surface 16, respectively. Surface 16 is generally
exposed when a flap 18 is formed in the surface of the cornea. An
inlay or implant 20 having a removable, pliable sheet 22 with
markings 24 thereon is positioned on the exposed surface of the
cornea, and the markings on the inlay are aligned with the markings
26 and 28. Preferably, this procedure is used for astigmatic
correction, but may be used with any type of correction to the
vision of the eye.
[0051] To begin, the refractive error in the eye is measured using
wavefront technology, as is known to one of ordinary skill in the
art. The refractive error measurements are used to determine the
appropriate shape of lens or inlay 20 to best correct the error in
the patient's cornea. Preferably, the inlay 20 is manufactured or
shaped prior to the use of the wavefront technology and is stored
in a sterilized manner until that specific inlay shape or size is
needed. However, the information received during the measurements
from the wavefront technology can be used to form the inlay using a
cryolathe, or any other desired system or machine.
[0052] As seen in FIG. 1, the main optical axis or visual axis 30
of the eye is marked with a dot 32 or any other type of marking,
such as cross-hairs or an X. The exact position of visual axis 30
of the eye 10 is determined by asking the patient to focus on a
small beam of light, as is known in the art, and the location on
the corneal surface is marked, using a marker (such as ink).
Preferably, the ink is any conventional ink that is water-soluble
and will be washed away after several blinks of the eye or
application of water or any other suitable liquid, thus allowing
unhindered sight by the patient.
[0053] A marking device 34, as seen in FIGS. 2 and 3, can then be
positioned adjacent the surface 12 of the cornea (FIG. 4). Device
34 is preferably formed of metal or plastic and has a handle 36 and
a substantially circular head 38. Head 38 is formed of a
substantially tubular or cylindrical portion 40 that extends from
the handle 36 in a substantially circular manner, leaving an
opening or area 42 within the tubular portion. Ten spokes 44 extend
radially from a central portion 46 to the tubular portion 40 at
equal intervals. In other words, the angle between each spoke 44
and the adjacent spoke is substantially equal to the angle between
each other adjacent spoke. Spokes 44 define five separate axes or
lines that extend from one portion of the tubular portion 40 to a
side opposite or about 180 degrees therefrom. Each spoke is
preferably substantially circular and in substantially the same
plane as each other spoke. The spokes 44, however, do not
necessarily need to be circular and spaced equally apart from one
another and can number any number desired, for example they can
number from one to as many can be fit into the desired area 42.
[0054] Once the marking device 34 is positioned adjacent the
external surface, the device 34 is centered using mark or dot 32.
Waterbased or removable ink (substantially similar to the ink used
to mark the visual axis) is then used to mark the surface 14 of the
cornea 12 along the spokes 44. As seen in FIG. 5, this leaves, ten
lines 26 extending radially from dot 32 or five axes extending in
separate directions. The lines 26 are in substantially the same
configuration as the marking device spokes 44.
[0055] Preferably, flap or portion 18 can be formed in the surface
14 of the cornea 12, as seen in FIG. 6. The flap is formed in the
stromal layer of the cornea, but does not necessarily need to be
formed in the stromal layer and can be formed in any desired
portion of the cornea. By forming the flap in the stromal layer,
the cells of the cornea do not cause a gray to white response in
the cornea, or protein detanurization The flap may be formed be any
means desired, such as with a knife, microkeratome, or with a
laser, such as a femtosecond laser or any other suitable laser.
[0056] Preferably, an internal area of the cornea is separated into
first and second substantially circular shaped internal surfaces 16
and 50, respectively, as seen in FIG. 8, to form the circular
shaped corneal flap 18. First internal surface 16 faces in an
anterior direction of cornea 12 and the second internal surface 50
faces in posterior direction of the cornea 12. The flap 18
preferably has a uniform thickness of about 10-250 microns, and
more preferably about 80-100 microns, but can be any suitable
thickness. A portion 52 of flap 18 preferably remains attached to
the cornea by an area at the periphery of the flap. However, the
flap can be any suitable configuration, such as a flap attached to
the cornea at a location other than at the periphery or a flap that
is not attached to the cornea at all. Additionally, the flap may be
shaped or sized as desired, and does not need to be circular.
[0057] As seen in FIG. 7, a tool or device or spatula needle 54 is
inserted under the flap 18, in between surfaces 16 and 50 and marks
the main optical or visual axis 30. The mark 56 is preferably made
on the first surface 16 and is lined up or positioned directly
under or in about the same position as mark 32 on the external
surface of the cornea.
[0058] The flap is moved or pivoted about portion 52 using any
device known in the art, such as a spatula or micro forceps or any
other device, to expose the first and second corneal surfaces 16
and 50, respectively. The flap preferably exposes a portion of the
corneal surface that intersects the main optical axis 30 and allows
uninhibited access thereto.
[0059] Device 34 is positioned adjacent the exposed surface 16 and
radial lines or axes 28 are made thereon using the removable ink,
described above. Lines 28 are made in substantially the same
positioning and placement as lines 26. In other words, lines 28
underlie lines 26, so that if flap 18 were replaced, lines 26 would
overlie lines 28 and each overlying line would indicate
substantially the same radian or axes. Lines 28 are formed in
substantially the same manner as lines 26 and the description
thereof applies to lines 28.
[0060] As seen in FIGS. 10 and 11, inlay or lens 20 is preferably a
substantially circular intracorneal inlay. Additionally, inlay 20
is preferably any polymer or hydrogel having about 70% to about 95%
water content, and more preferably of about 78% to about 80% water
content; however, the water content can be any percentage desired.
The inlay may be formed from synthetic or organic material or a
combination thereof. For example, the inlay can be collagen
combined with or without cells; a mixture of synthetic material and
corneal stromal cells; silicone or silicone mixed with collagen;
methylmetacrylate; any transparent material, such as polyprolidine,
polyvinylpylidine, polyethylenoxyde, etc.; or any deformable
polymer, which can change its shape with radiation after
implantation.
[0061] Furthermore, inlay 20 has a first side or surface 58 and a
second side or surface 60, and is preferably shaped with an
asymmetrical cross-section, as seen specifically in FIG. 11, so
that it can correct astigmatic error in the eye. Preferably, as
stated above, inlay 20 may come in many configurations and not
necessarily that shown in FIG. 11, to correct any different degrees
and variations of astigmatic error. Furthermore, inlay 20 may be
used to correct hyperopia, myopia or any other vision problems or a
combination of these vision problems and astigmatism.
[0062] Second surface 60 preferably is curved and pliable, so that
it is able to conform to the first surface 16 of the cornea 12. The
implant is preferably substantially circular, having a diameter of
between about 2-10 mm and can have a refractive index different
than that of the cornea or the same as that of the cornea
Preferably, the inlay has a refractive index of about 1.2 to 1.4,
and more preferably of about 1.33. If the refractive index is the
same as the cornea, the total refractive index of the cornea is
altered after implantation of the inlay and repositioning of the
flap. However, the inlay can be any size and/or configuration
desired.
[0063] Furthermore, as seen in FIG. 11, a pliable or bendable sheet
or film of transparent material 62 is positioned to overlie and
conform to surface 58. Sheet 62 is preferably a synthetic material,
such as any suitable polymer, and is substantially circular with
markings or lines 24 thereon. Markings 24 have substantially the
same positioning and placement as lines 26 and 28, or are 10 lines
that radially extend from a center to form five separate axes. The
description of lines 26 and 28 applies to markings 24. In other
words, lines 24 are configured in such a manner that if the center
of the markings 24 was placed on the marking 32 the lines can be
adjusted or orientated so that markings 24 would overlie lines 28
and/or 26, each line indicating substantially the same radian or
axis. Furthermore the center 66 of the markings 24 is preferably in
the center of the inlay or positioned in any predetermined portion
of the inlay.
[0064] This configuration of the lines and markings 28 and 24
allows the inlay to be placed on the exposed surface of the cornea
directly over the visual axis 30 and oriented so that lines and
markings 28 and 24 are precisely or substantially matched, as seen
in FIG. 14. Furthermore, by placing the markings on the inlay and
the cornea as described, an asymmetric astigmatic inlay can be
correctly and accurately placed on the exposed surface of the
cornea It is generally crucial to the sight of the patient's eye,
especially during astigmatic correction, to have the inlay
precisely oriented to correct the existing error. If the inlay is
not both centered over the visual axis, or at least positioned in a
predetermined position over the visual axis, and oriented properly
with respect to radial position, the inlay will not correct the
desired astigmatic error and may even increase the refractive error
in the cornea Therefore, it can be seen that this inlay can be
accurately positioned both radially and centrally on the eye to
improve the vision of the eye.
[0065] Preferably, inlay 20 is positioned adjacent the surface of
the cornea, using tool or holding device 80, in-between first and
second corneal surfaces 16 and 50. As seen in FIGS. 12 and 13, tool
80 is preferably a plastic tool having a handle 82 and a
substantially circular head 84; however, tool 80 can be any
material and shape desired that would allow the placement of inlay
20 on a corneal surface. Head 84 has an open center portion 86
defined by an L-shaped holding portion 88, which is curved in a
similar configuration as the surface of the cornea to facilitate
positioning of the inlay; however, portion 88 can be straight or
any other configuration desired. Portion 88 has a bottom wall 90
and a sidewall 92 that are sized and configured to hold inlay 20
therein (FIGS. 14 and 15). Additionally, wall 90 has markings or
lines 91 that are substantially similar and oriented to the lines
or markings 24 on the inlay. These markings allow the inlay to be
aligned with the tool 80 when positioning the inlay adjacent the
cornea. Furthermore, the walls 86 and 88 have an opening 94 at one
end, preferably opposite or 180-degrees away from the handle 92.
The opening allows the resilient head to separate and the inlay to
be properly positioned in the exact or precise location desired on
the exposed corneal surface, after it is aligned with the markings
of the corneal surface, as described above.
[0066] It is noted that the inlay can be positioned without the use
of tool 80, in any convention manner desired or any other manner,
and does not necessarily need to be positioned on an internal
surface of the cornea but may be placed or positioned on the
external surface of the cornea.
[0067] Once tool 80 is removed and the inlay properly positioned,
the flap 18 is replaced so that it covers or lies over the sheet 62
in a relaxed state, as seen in FIGS. 16 and 17. In other words,
inlay 20 or sheet 62 does not force flap 18 away from the internal
surface 58 and therefore the refractive properties of the cornea
are not altered due to a tension force being applied to the flap.
Preferably, the flap 18, the inlay 20, the visual axis 30 and
surface 16 are all precisely lined up using the above described
markings and lines. If any markings are off, the inlay and/or the
flap can be repositioned by using small forceps. The forceps can be
extended underneath the flap 18 to move the inlay with respect to
the visual axis either in a: rotational or a linear manner.
[0068] As seen in FIGS. 16 and 17, forceps 68 are used in grasp the
sheet 62 and move the sheet from the surface of the inlay, thus
removing any markings on the inlay 20 that may hinder sight.
Additionally, the markings on the eye would wash away after a short
period of time due to the liquids developed naturally by the eye;
however, if desired the ink my be washed of manually with the
application of water or any other suitable liquid. Furthermore, it
is noted that the sheet does not necessarily need to be removed and
can remain on the inlay even after the procedure is completed. The
ink on sheet 62 may be removable in the same manner as the ink to
mark the cornea and would thus wash off after a short time
period.
[0069] Additionally, the markings may be placed directly on the
inlay and do not necessarily need to be on a sheet. This type of
marking would allow the same proper placement without the need to
remove the sheet. As stated above, the ink forming the markings
could be removable.
[0070] It is noted that the markings do not necessarily need to be
in the configuration described and can be any type of markings
desired. For example, the markings can be radial dots that are
positioned along the desired axes or radians or they can be
concentric circles or a single circle or any other polygon desired
or configuration of marks or dots desired that would allow the
matching of the inlay, flap and surface of the cornea in the manner
described above. Furthermore, the markings do not need to be
removable and can be permanent, whether they are made with ink or
actual alterations to the cornea and/or inlay, or the markings can
be any combination of removable and/or permanent markings.
[0071] As seen in FIGS. 19 and 20, the inlay can be a ring-shaped
inlay 120 with first and second surfaces 158 and 160 lay 120 is
formed from substantially similar materials and therefore would
have substantially similar properties to those of inlay 20 and
therefore, the description thereof applies to the material and
properties of inlay 120. As seen in FIG. 19, the inlay can have one
portion that is larger than another portion, or in other words an
asymmetric configuration that would correct astigmatic error as
described above.
[0072] Inlay 120 can be used for correction of myopia or
astigmatism or both. As with the above-described inlay, inlay 120
has a sheet of pliable, transparent material 162 overlying surface
158. However, sheet 162 is preferably ring-shaped and covers the
ring-shaped portion of inlay 120. Furthermore, as with sheet 62,
sheet 162 can be used to position and orientate inlay 120 relative
to both the corneal flap 18 and the corneal surface 16 and the
visual axis 30, as described above. Sheet 162 can also be removed
in a similar manner as to that described above for sheet 62.
[0073] As seen in FIGS. 21 and 22, inlay 220 can be a ring-shaped
inlay similar to inlay 120 but with portion portions 220a and 220b.
As seen specifically in FIG. 22, portion of the inlay 220a can be
larger than portion 220b for correction of astigmatic error, as
described above. Furthermore sheet 262 can overlie the inlay in a
similar manner as sheet 162. However, sheet 262 has two portions
262a and 262b, which overlie portions 220a and 220b, respectively.
Inlay 220 is substantially similar to inlay 120 and inlay 20 and
the descriptions thereof apply to inlay 220.
[0074] Additionally, the entire procedure for inlay 20 is
applicable to both inlay 120 and inlay 220 and any description
thereof is applicable to inlays 120 and 220.
[0075] While various advantageous embodiments have been chosen to
illustrate the invention, it will be understood by those skilled in
the art that various changes and modifications can be made therein
without departing from the scope of the invention as defined in the
appended claims.
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