U.S. patent application number 13/769064 was filed with the patent office on 2013-11-21 for intraocular lens with accommodation.
The applicant listed for this patent is Anew Optics, Inc. Invention is credited to Robert E. Kellan.
Application Number | 20130310932 13/769064 |
Document ID | / |
Family ID | 38576437 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130310932 |
Kind Code |
A1 |
Kellan; Robert E. |
November 21, 2013 |
Intraocular Lens with Accommodation
Abstract
An intraocular lens (IOL) assembly for correcting myopia,
hyperopia and astigmatism using the intraocular lens assembly are
provided. In particular, the intraocular lens assembly comprises a
lens extending along an optical axis between an anterior optical
surface and a posterior optical surface. The IOL has a
circumferential edge disposed about the optical axis at a junction
of anterior and posterior optical surfaces. The IOL assembly
further has N haptics, where N is an integer greater than 1. Each
haptic extends from an associated portion of the circumferential
edge and along an associated haptic axis. In addition, each haptic
is loop-like or paddle-like and extends between end portions at
opposite ends thereof. The end portions are joined to the lens at
the circumferential edge. The resultant vaulted structure provides
an intraocular lens assembly that, when implanted in the eye,
allows accommodation.
Inventors: |
Kellan; Robert E.; (North
Andover, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Anew Optics, Inc |
Bristol |
TN |
US |
|
|
Family ID: |
38576437 |
Appl. No.: |
13/769064 |
Filed: |
February 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11398412 |
Apr 5, 2006 |
8377125 |
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13769064 |
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13361688 |
Jan 30, 2012 |
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11398412 |
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12626473 |
Nov 25, 2009 |
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13361688 |
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61118085 |
Nov 26, 2008 |
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61157781 |
Mar 5, 2009 |
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61184655 |
Jun 5, 2009 |
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61500203 |
Jun 23, 2011 |
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61437291 |
Jan 28, 2011 |
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Current U.S.
Class: |
623/6.37 ;
623/6.51 |
Current CPC
Class: |
A61F 2/1629 20130101;
A61F 2/1616 20130101; A61F 2002/1681 20130101; A61F 2/1602
20130101 |
Class at
Publication: |
623/6.37 ;
623/6.51 |
International
Class: |
A61F 2/16 20060101
A61F002/16 |
Claims
1. An intraocular lens assembly comprising: a lens extending along
an optical axis between an anterior optical surface and a posterior
optical surface and having a circumferential edge disposed about
said optical axis at a junction of said anterior and posterior
optical surfaces, and having N haptics, each of said haptics
extending from an associated portion of said circumferential edge
and along an associated haptic axis, where N is an integer greater
than 1, wherein each of said haptics has a smooth, curved
peripheral edge and extends between end portions at opposite ends
thereof, said end portions being joined to said lens at said
circumferential edge.
2. An intraocular lens assembly according to claim 1, wherein said
haptics are loop-like.
3. An intraocular lens assembly according to claim 1, wherein said
haptics are paddle-like.
4. An intraocular lens assembly according to claim 1, having a
first pair of haptics extending from opposite portions of said
circumferential edge along an associated first pair of haptic axes,
and having a second pair of haptics extending from opposite
portions of said circumferential edge along an associated second
pair of haptic axes, wherein said first pair of haptic axes and
said optic axis are coplanar in a first haptic plane wherein said
second pair of haptic axes and said optic axis are coplanar in a
second haptic plane.
5. An intraocular lens assembly according to claim 4 wherein said
first haptic plane is perpendicular to said second haptic
plane.
6. An intraocular lens assembly according to claim 5 wherein said
haptics are angularly displaced with respect to said optical axis
in a direction away from said anterior optical surface by an angle
A from a plane transverse to said optical axis.
7. An intraocular lens assembly according to claim 6 wherein A is
in the approximate range 4-7 degrees.
8. An intraocular lens assembly according to claim 4 wherein each
of said haptics includes M footplates extending therefrom
symmetrically about its associated haptic axis, where M is an
integer greater than 0.
9. An intraocular lens assembly according to claim 8 where M=1 for
each of said haptics.
10. An intraocular lens assembly according to claim 4 wherein each
of said haptics includes M footplates, where M=0.
11. An intraocular lens assembly according to claim 5 wherein each
of said haptics includes M footplates extending therefrom
symmetrically about its associated haptic axis, where M is an
integer greater than 0.
12. An intraocular lens assembly according to claim 11 where M=1
for each of said haptics.
13. An intraocular lens assembly according to claim 5 wherein each
of said haptics includes M footplates, where M=0.
14. An intraocular lens assembly according to claim 6 wherein each
of said haptics includes M footplates extending therefrom
symmetrically about its associated haptic axis, where M is an
integer greater than 0.
15. An intraocular lens assembly according to claim 14 where M=1
for each of said haptics.
16. An intraocular lens assembly according to claim 6 wherein each
of said haptics includes M footplates, where M=0.
17. An intraocular lens assembly according to claim 7 wherein each
of said haptics includes M footplates extending therefrom
symmetrically about its associated haptic axis, where M is an
integer greater than 0.
18. An intraocular lens assembly according to claim 17 where M=1
for each of said haptics.
19. An intraocular lens assembly according to claim 7 wherein each
of said haptics includes M footplates, where M=0.
20. An intraocular lens assembly according to claim 1 wherein each
of said haptic axis is coplanar with said optic axis in an
associated haptic plane.
21. An intraocular lens assembly according to claim 1 where N is
odd.
22. An intraocular lens assembly according to claim 21 where
N=3.
23. An intraocular lens assembly according to claim 21 where
N=5.
24. An intraocular lens assembly according to claim 1 where N is
even.
25. An intraocular lens assembly according to claim 24 where
N=2.
26. An intraocular lens assembly according to claim 24 where
N=4.
27. An intraocular lens assembly according to claim 1 wherein each
of said haptics includes M footplates extending therefrom
symmetrically about its associated haptic axis, where M is an
integer greater than 0.
28. An intraocular lens assembly according to claim 27 where M=1
for each of said haptics.
29. An intraocular lens assembly according to claim 1 wherein each
of said haptics includes M footplates, where M=0.
30. An intraocular lens assembly according to claim 20 wherein each
of said haptics includes M footplates extending therefrom
symmetrically about its associated haptic axis, where M is an
integer greater than 0.
31. An intraocular lens assembly according to claim 30 where M=1
for each of said haptics.
32. An intraocular lens assembly according to claim 20 wherein each
of said haptics includes M footplates, where M=0.
33. An intraocular lens assembly according to claim 1, wherein the
intraocular lens assembly includes either a monofocal or multifocal
lens.
34. A method for implanting a phakic intraocular lens assembly in
an eye, comprising: inserting into the eye, a lens extending along
an optical axis between an anterior optical surface and a posterior
optical surface and having a circumferential edge disposed about
said optical axis at a junction of said anterior and posterior
optical surfaces, and N haptics, each of said haptics extending
from an associated portion of said circumferential edge and along
associated haptic axis, where N is an integer greater than 1,
wherein each of said haptics has a smooth, curved peripheral edge
and extends between end portions at opposite ends thereof, said end
portions being joined to said lens at said circumferential
edge.
35. An intraocular lens assembly according to claim 34, wherein
said haptics are loop-like.
36. An intraocular lens assembly according to claim 34, wherein
said haptics are paddle-like.
37. The method of claim 34 wherein said haptic axis are angulated
away from said anterior surface by angle A with respect to a plane
transverse to said optical axis.
38. The method of claim 37 wherein A is in the approximate range
4-7 degrees.
39. The method of claim 34 wherein the intraocular lens assembly
includes an aphakic intraocular lens assembly.
40. The method of claim 34 permitting the eye to heal in the
absence of a ciliary muscle relaxant; wherein the implanted
intraocular lens provides an accommodating lens to the eye.
Description
TECHNICAL FIELD
[0001] The present invention relates to implantable intraocular
lenses ("IOL") suitable for the correction of myopia, hyperopia,
and astigmatism. More particularly, the invention relates to IOLs
which are adapted to provide accommodation.
BACKGROUND ART
[0002] Implantation of artificial lenses into the human eye has
been a standard technique for many years, both to replace the
natural crystalline lens (aphakic eye) and to supplement and
correct refractive errors of the natural lens (phakic eye).
However, accommodation provided by such replacement lenses is
minimal or non-existent.
[0003] The human eye includes an anterior chamber between the
cornea and iris, a posterior chamber, defined by a capsular bag
containing a crystalline lens, a ciliary muscle, a vitreous chamber
behind the lens containing the vitreous humor, and a retina at the
rear of this chamber. The human eye has a natural accommodation
ability. The contraction and relaxation of the ciliary muscle
provides the eye with near and distant vision, respectively. This
ciliary muscle action shapes the natural crystalline lens to the
appropriate optical configuration for focusing light rays entering
the eye on the retina.
[0004] After the natural crystalline lens is removed, for example,
because of cataract or other condition, a conventional, monofocal
IOL can be placed in the posterior chamber. Such a conventional IOL
provides very limited, if any, accommodation. However, the wearer
of such an IOL continues to require the ability to view both near
and distant objects. Corrective spectacles may be employed as a
useful solution. Recently, multifocal IOLs, defractive or
refractive, divide light entering the eye and have been used to
provide near and distant vision correction. Though they do provide
some accommodation, they decrease contrast sensitivity and cause
photopic problems such as glare and halos.
[0005] Examples of implantable intraocular lenses include various
design configurations without providing significant accommodation.
Generally, the lenses are attached in some manner to the eye,
usually by the use of sutures or some other supporting means, such
as arms or haptics, extending from the optical lens portion of the
intraocular lens.
[0006] U.S. Pat. No. 6,241,777 describes a phakic intraocular lens
assembly that has a lens with a circumferential edge, and a first
haptic and a second haptic, which extend from the edge of the lens.
Each of the haptics has a first leg extending from the lens edge to
a distal end, and a second leg extending from the lens edge to a
distal end, and a transverse member extending between the distal
ends of each first and second leg. The transverse member can be
substantially straight or bowed inward toward the lens. Each leg
has a footplate at its distal end.
[0007] U.S. Pat. No. 6,261,321 (Continuation-in-part of U.S. Pat.
No. 6,241,777) describes a phakic or aphakic intraocular lens
assembly that has a lens with a circumferential edge, and a first
haptic and a second haptic, which extend from the edge of the lens.
Each of the haptics has a first leg extending from the lens edge to
a distal end, and a second leg extending from the lens edge to a
distal end, and a transverse member extending between the distal
ends of each first and second leg. The transverse member can be
substantially straight or bowed inward toward the lens. Each leg
has a footplate at its distal end. Each leg of each haptic may be
inwardly bowing, straight, and outwardly bowing. Additionally, each
leg may have the same or different shape from the other legs.
[0008] U.S. Pat. No. 6,015,435 describes a self-centering phakic
intraocular lens inserted in to the posterior chamber lens for the
correction of myopia, hyperopia, astigmatism, and presbyopia.
Haptic bodies are attached to optical body and extend outward from
tangent points at the edge of lens in at least two generally
opposite directions. Protruding surfaces protrude into pupil such
that the iris interferes slightly with lens movement and provides
the centering force to keep lens in place.
[0009] U.S. Pat. No. 5,133,747 describes an intraocular lens device
that is partially or completely within the anterior capsular
surface of the human crystalline lens. In one embodiment, the optic
body has asymmetrical haptics extending outwardly from opposite
sides of the circumferential edge of the optic body. In one
embodiment, "J" shaped haptics extend from the circumferential edge
of the optic body in a manner that encircles optic body. In another
configuration, the haptics extend tangentially away from body, then
reverse direction, giving the device an overall "S" shape with the
lens at center portion of the S. The device is secured in place
with an adhesive.
[0010] Attempts have been made to provide IOLs with accommodation,
using movement along the optical axis of the eye as an alternative
to shape changing. Examples of such attempts are set forth in Levy
U.S. Pat. No. 4,409,691 and several patents to Cumming, including
U.S. Pat. Nos. 5,674,282 and 5,496,366. These lenses are biased to
be located in the posterior-most position in the eye under rest or
resting conditions. When near focus is desired, the ciliary muscle
contracts and the lens moves forwardly (positive accommodation). In
the absence of ciliary muscle contraction, the lens moves rearward
to its posterior-most resting position. Because of this posterior
bias and the configuration of the lens, the posterior wall of the
capsular bag is subjected to a substantial degree of stretching
when the lens is in the posterior-most position. One problem that
exists with such IOLs is that they often cannot move sufficiently
to obtain the desired accommodation.
[0011] Therefore, it would be advantageous to provide IOLs which
can achieve an acceptable amount of accommodation with reduced risk
of damaging the capsular bag.
SUMMARY OF THE INVENTION
[0012] An intraocular lens (IOL) assembly and method for correcting
myopia, hyperopia and astigmatism using the intraocular lens
assembly are provided. In particular, the intraocular lens assembly
relates to intraocular lenses which provide accommodation. The
intraocular lens assembly comprises a lens extending along an
optical axis between an anterior optical surface and a posterior
optical surface. The lens has a circumferential edge disposed about
the optical axis at a junction of anterior and posterior optical
surfaces. The lens further has N haptics, where N is an integer
greater than 1. Furthermore, each haptic extends from an associated
portion of the circumferential edge and along an associated haptic
axis. In addition, each haptic is "loop-like" or "paddle-like" and
extends between end portions at opposite ends thereof joined to the
lens at the circumferential edge. It should be noted that each of
the haptics may include M footplates extending symmetrically about
its associated haptic axis, where M is an integer greater than 0.
Alternatively, each of the haptics may not include any
footplates.
[0013] In one embodiment of the present invention, an intraocular
lens assembly may include a first pair of haptics extending from
opposite portions of circumferential edge along an associated first
pair of haptic axes, and having a second pair of haptics extending
from opposite portions of circumferential edge along an associated
second pair of haptic axes, wherein first pair of haptic axes and
optic axis are coplanar in a first haptic plane wherein second pair
of haptic axes and optic axis are coplanar in a second haptic
plane. In addition, the first haptic plane may be perpendicular to
second haptic plane, although angle arrangements other than
perpendicular may be used in other forms of the invention. The
haptics are angularly displaced with respect to optical axis in a
direction away from the anterior optical surface by an angle A from
a plane P transverse to optical axis. In an embodiment, an
intraocular lens assembly can have an angle A with an approximate
range of 4-7 degrees. It should also be noted that each haptic may
include at least one footplate extending therefrom symmetrically
about its associated haptic axis. Alternatively, each of the
haptics may not include any footplates.
[0014] The invention also provides a method for implanting in an
eye an intraocular lens assembly which provides accommodation. This
includes the insertion of an intraocular lens (IOL) assembly into
the eye, where the IOL assembly extends along an optical axis
between an anterior optical surface and a posterior optical
surface. The lens of the IOL has a circumferential edge disposed
about an optical axis at a junction of the anterior and posterior
optical surfaces. The lens further includes N haptics, where N is
an integer greater than 1. Each haptic extends from an associated
portion of the circumferential edge and along an associated haptic
axis. Each of the haptics is "loop-like" or "paddle-like" and
extends between end portions at opposite ends thereof. The end
portions are joined to the lens at the circumferential edge. Also,
the haptic axis is angulated away from anterior surface by angle A
with respect to a plane P transverse to the optical axis. In one
embodiment, angle A may be in an approximate range of 4-7
degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention, and the various features thereof, may be more
fully understood from the following description, when read together
with the accompanying drawings, in which:
[0016] FIGS. 1 and 1A show a top view and a perspective view of the
lens assembly of an embodiment of the present invention.
[0017] FIG. 2 shows a cross sectional view of the lens assembly of
FIG. 1 along axis A.
[0018] FIG. 3 shows a top view of an alternative embodiment of the
lens assembly with orientation tabs.
[0019] FIG. 4A shows a cross-sectional view of an eye with an
phakic intraocular lens assembly of an embodiment of the present
invention.
[0020] FIG. 4B shows a cross-sectional view of an eye with an
aphakic intraocular lens assembly of an embodiment of the present
invention.
[0021] FIG. 5A-5I show top views of alternative embodiments of lens
assemblies of the present invention, with examples of haptic
placement along a circumferential edge of a lens.
DETAILED DESCRIPTION OF THE INVENTION
[0022] In the eye, the natural lens of the eye separates the
aqueous humor from the vitreous body. The iris separates the region
between the cornea or anterior of the eye and the lens into an
anterior chamber and a posterior chamber. The natural crystalline
lens is contained in a membrane known as the capsule or capsular
sac. When the natural lens is removed from the eye, the capsule may
also be removed (intracapsular excision), or the anterior portion
of the capsule may be removed with the natural crystalline lens,
leaving the posterior portion of the capsule intact (extracapsular
extraction), often leaving small folds or flaps from the anterior
portion of the capsule. In an intraocular implant, an artificial
lens may be inserted in the anterior chamber, the posterior
chamber, or the capsular sac.
[0023] The design of intraocular lens assembly of the present
invention and particularly the loop-like or paddle-like, flexible
haptics, preferably with angulation, overcomes the lack of
accommodation provided by prior intraocular devices. The
intraocular lens assembly of the invention is primarily designed
for placement in the anterior chamber of the eye and use as a
refractive lens for the phakic eye. However, the unique design of
the intraocular lens assembly also permits its use in the aphakic
eye, and placement in the posterior chamber sulcus and the
posterior chamber bag. The intraocular lens assembly described
herein is suitable for correction of myopia, hyperopia, and
astigmatism without compromising the anatomy or physiology of the
eye.
[0024] The intraocular lens assembly of the invention is made from
a biocompatible, flexible material. In one embodiment, the material
is also a foldable material, which allows insertion of the device
through small incisions, usually 3 mm or less. Since the device is
preferably inserted into the anterior chamber of the eye, there is
no contact with the natural crystalline lens, so that cataract
formation is minimized. The design provides minimal contact with
other tissues in the eye. Furthermore, the device can be easily
removed and reinserted as needed. The combination of flexible
materials and the haptic design allows the device to withstand some
deforming forces, such as the patient rubbing his eyes, without the
device breaking, warping, or becoming disengaged from the eye.
[0025] In one embodiment of the present invention, as illustrated
in FIG. 1, an intraocular lens assembly 10 includes a lens portion
(the "optic") 12 extending along an optical axis OA between an
anterior optical surface and a posterior optical surface. The lens
12 of the IOL has a circumferential edge 8 (disposed about the
optical axis OA) at a junction of anterior and posterior optical
surfaces. The lens 12 has two pairs of opposed, flexible haptics
14A, 14B, and 15A, 15B extending from circumferential edge 8 of
optic 12. The haptics extend along an associated haptic axis HA:
haptic 14A extends along haptic axis HA-14A, haptic 14B extends
along haptic axis HA-14B, haptic 15A extends along haptic axis
HA-15A and haptic 15B extends along haptic axis HA-15B. In the
illustrated embodiment, each haptic axis HA is coplanar with
optical axis OA in an associated haptic plane. In other
embodiments, a different number of haptics may be employed. For
example there may be N haptics, where N is an integer.
[0026] Each of the flexible, haptics 14A, 14B, 15A and 15B are
flexible and "loop-like" or "paddle-like". As used here, the term
"loop-like" refers to a smooth, curved portion of a loop, for
example, having a "C-shaped" or U-shaped peripheral edge, with
uniform or non-uniform width. As used herein, the term
"paddle-like" refers to a solid element (without a central
aperture) bounded by a C-shaped or U-shaped peripheral edge. The
haptics extend between end portions thereof which are joined to
lens 12 at associated portions of circumferential edge 8. For
example, haptic 14A extends between EP-14A and EP-14B, extending
along haptic axis, HA-14A.
[0027] In the illustrated embodiments of FIG. 1, two pairs of
opposed, flexible, loop-like haptics are spaced equidistant around
circumferential edge 8 of optic 12. This symmetry provides the
comfort to the patient and stability of the lens. Alternatively,
two or more loop-like, flexible haptics may be attached at
differently spaced, non-equidistant points or asymmetrically on a
circumferential edge 8 extending along haptic axis HA, see FIGS.
5D-5G. In addition, two or more flexible haptics may be attached,
depending upon the individual eye anatomy or vision requirements,
to maximize accommodation and stability of the lens assembly.
[0028] As shown in FIG. 1A, the intraocular lens assembly 10
includes a first pair of haptics 14A, 14B extending from opposite
portions of circumferential edge 8 (in a plane P) along an
associated first pair of haptic axes HA-14A, HA-14B and a second
pair of haptics 15A, 15B extending from opposite portions of
circumferential edge 8 along an associated second pair of haptic
axes HA-15A, HA-15B, wherein first pair of haptic axes and optic
axis OA are coplanar in a first haptic plane HP1 and wherein second
pair of haptic axes and optic axis OA are coplanar in a second
haptic plane HP2. In addition, the first haptic plane HP1 is
perpendicular to second haptic plane HP2. The haptics are angularly
displaced with respect to optical axis in a direction away from
anterior optical surface by an angle A from the plane P transverse
to optical axis OA. Preferably, the intraocular lens assembly uses
an angle A with an approximate range of 4-7 degrees. It should also
be noted that each haptic includes at least one footplate FP
extending therefrom symmetrically about its associated haptic axis
HA. Alternatively, each of the haptics may not include any
footplates extending symmetrically about its associated haptic
axis.
[0029] Each haptic includes M footplates FP extending symmetrically
about its associated haptic axis HA, where M is an integer greater
than 0. In one embodiment, M equals 1. Alternatively, each of the
haptics may not include any footplates. In FIGS. 1 and 1A, the
footplates FP are integrally formed on the distal end of each
haptic HA, preferably at the apex of the haptic. As illustrated in
FIG. 1, each haptic 14A, 14B, 15A, and 15B includes an associated
one of footplates FP-14A, FP-14B, FP-15A, and FP-15B disposed
symmetrically about its associated haptic axis HA-14A, HA-14B,
HA-15A, and HA-15B. In other embodiments, there may be multiple
footplates symmetrically disposed about the associated haptic axis.
By way of example, various footplate configurations are shown in
FIGS. 5A-5I. Note, in one embodiment, the configurations may not
have any footplates. It should also be noted that footplates FP are
preferably lenticular-shaped in cross-section to allow for minimal
contact with the eye structures yet provide the required stability
for the desired visual results. FIGS. 5A-5E and 5I show loop-like
haptics, where FIGS. 5A-5C show uniform width haptics and FIGS.
5D-5G show non-uniform width haptics. FIG. 5H shows paddle-like
haptics.
[0030] FIG. 2 shows an intraocular lens assembly, similar to
intraocular lens assembly 10 of FIG. 1, along plane HP1 defined by
optical axis OA and haptic axis HA-14A and HA-14B. Optic 22
constitutes the optical portion of the lens assembly. The optic 22
comprises an anterior optical surface 24 and posterior optical
surface 26. The combination of surface 24 and surface 26 may result
in the optic being substantially planar, convex, plano-convex
(illustrated in FIG. 2) and concave, bi-convex, concave-convex, or
other known form. The diameter of optic 22 can vary as needed to
accommodate the angle-to-angle measurement of the eye and curvature
of the eye. The overall length of the intraocular lens (optic and
haptics) to be inserted into an individual patient's eye is
determined by adding a 1 mm white-to-white measurement of the
patient's eye. In one embodiment, Optic 22 has a 6 mm optical
zone.
[0031] Optic 22 may be ground to the required diopter measurements
necessary for vision correction. The lens may be a negative or
positive meniscus lens and may include correction for astigmatism.
Depending on the refractive index of the material used, and the
required vision correction, optic 22 may have the same thickness at
central portion 27 and circumferential edge 28, or central portion
27 may be thinner than circumferential edge 28. In one embodiment,
the thickness of optic 22 is 1 mm.
[0032] In another embodiment, still referring to FIG. 2, flexible
haptics 14A and 14B extend from circumferential edge 28 of optic 22
at a slight angle A from a plane P transverse to the optical axis
OA. Vault distance V for assembly 20 is defined as the height of
the lens assembly measured from a line Q, which is drawn
horizontally (as shown) between footplates FP, to the apex 29 of
inner optical surface 24 and along the optical axis OA. Angle A is
in the approximate range 4 to 7 degrees, or more, as desired, to
maximize accommodation of lens assembly 20. Preferably angle A is
one that, when in combination with the size and shape of the optic
and the flexible haptics and the assembly 20, and the anatomical
angle of the eye, provides a 1 mm vault distance V, although other
vault distances can be used. The vault distance insures adequate
clearance for the intraocular lens assembly to be situated between
the natural crystalline lens and the cornea in the anterior
chamber.
[0033] As illustrated in FIG. 3, there is shown an intraocular lens
assembly, similar to intraocular lens assembly 10 in FIG. 1, that
includes a tab A and a tab B, extending from the circumferential
edge 38 of optic 32. Those tabs assist the user (surgeon) in the
identification of orientation of the lens assembly during
implantation. The "left diagonal" orientation of the tabs is shown
in FIG. 3, as viewed by the surgeon, indicate that the lens
assembly is correctly implanted, with the lens being
vaulted-forward. A left-diagonal orientation of tabs A and B would
indicate that lens assembly 30 has been implanted in a backwards or
reversed manner.
[0034] The preferred embodiment intraocular lens assembly of the
invention is designed to be foldable to facilitate insertion
through small incisions, generally 3 mm in length or less. The
device can be folded along axis A, transverse to axis A, at an
angle offset from axis A, or in multiple directions. The device can
be folded in the optic body, at any point in the flexible haptics,
at the junction points between the optic body and the flexible
haptics, or all of the above. The device can be folded with single
or multiple folds along each direction.
[0035] Suitable materials for the lens assembly of the invention
are solid, flexible, foldable optical, non-biodegradable materials
such as hydrogel, collamer, collagel (hydrogel-collagen blends)
acrylic polymers, polymethylmethacrylate (PMMA) and silicone
polymers. The lens assembly may also be made of a composite of
materials, i.e. where the flexible haptics are fabricated from one
material and the optics from another material, for example, acrylic
optics and hydrogel haptics. Where the lens assembly is used in the
aphakic eye, flexible, but less foldable, materials may be
preferred. For example, for the aphakic eye, the lens assembly may
be made of all PMMA or a composite of PMMA optics and prolene
haptics.
[0036] By way of example, the lens assembly may be made as a
sterile UV-absorbing acrylic foldable form, for example using the
same material as the AcrySof.TM. IOL manufactured by Alcon
Laboratories, Inc. Moreover, in various forms the lens may be used
in the anterior chamber, the posterior chamber sulcus and the
posterior chamber bag.
[0037] In FIG. 4A, a phakic intraocular lens assembly 40 of the
invention implanted is shown, in the anterior chamber of the eye 43
and fixated in the angle 44. Alternatively, the phakic IOL of the
invention may be implanted in the posterior chamber of the eye and
fixated in the angle. Lens assembly 40 is positioned in anterior
chamber C, between cornea 45 and iris 46. An optic 47 of assembly
40 is positioned over pupil 48. Flexible haptics 49 extend from
optic 47, with footplates FP (distal from optic 47), extending into
angle 44. With the configuration, movement of natural crystalline
lens 50 is unobstructed in the posterior chamber 42. The relatively
low vault height of lens assembly 40 insures that it does not
contact cornea 44.
[0038] In FIG. 4B, an aphakic intraocular lens assembly 40 of the
invention is shown, implanted in the capsular bag of the eye 43.
Alternatively, the aphakic IOL of the invention may be implanted in
the sulcus of the eye. Lens assembly 40 is positioned in capsular
bag P, behind the iris 46 and cornea 45. An optic 47 of assembly 40
has flexible haptics 49, along with footplates FP (distal from
optic 47), extending into angle 44. The relatively low vault height
of lens assembly 40 insures that it does not contact cornea 44.
[0039] As mentioned above, the intraocular lens assembly of the
invention can be usefully implanted into the eye as either a
refractive phakic intraocular lens assembly or an aphakic
intraocular lens assembly. Phakic intraocular lens implantation is
becoming more popular because of their good refractive and visual
results and because they are relatively easy to implant in most
cases (Zaldivar & Rocha, 36 Int. Ophthalmol. Clin. 107-111
(1996); Neuhann et al., 14 J. Refract. Surg. 272-279 (1998); Rosen
& Gore, 24 J. Cataract Refract. Surg. 596-606 (1998); Sanders
et al., 24 J. Cataract Refract. Surg. 607-611 (1998). The
implantation can be performed by an ordinarily skilled
ophthalmologist. Little surgical injury occurs to the ocular
tissues during such implantation. When the surgical quality is not
compromised, the results are highly predictable, immediate, and
lasting.
[0040] Phakic lens assembly implantation using the intraocular lens
assembly of the invention has advantages over other forms of
surgical vision enhancement. Unlike laser surgery, the implants are
removable. The natural crystalline lens remains, and the patient
doesn't lose the ability to accommodate. Refractive surgery by
phakic intraocular lenses among patients with hyperopia is not yet
as popular as patients with myopia, but primarily because such
surgery has not been available for as long (Fechner et al., 24(1)
J. Cataract Refract. Surg. 48-56 (1998)).
[0041] For a phakic lens assembly implantation, the intraocular
lens assembly of the invention is preferably located in the
anterior chamber of the eye. Following the appropriate
implantation, the intraocular lens of the assembly invention can be
either an angle-supported phakic intraocular lens located in front
of the iris or a sulcus-supported phakic intraocular lens located
behind the iris. The haptic lens features of the intraocular lens
assembly of the invention fixate the distal haptic portions of the
lens, thus preventing dislocation and slipping or shifting of the
intraocular lens from its proper position.
[0042] The implantation assembly of the intraocular lens assembly
of the invention can generally be performed as provided by (Singh,
emedicine Ophthalmology (2000)
http://www.emedicine.com/cgi-bin/foxweb.exe/showsection@d:/em/ga?book=oph-
&topicid=662):
[0043] First, the administration of local antibiotic drops is
begun. A useful antibiotic is Tobramycin 0.3%, 1 drop, 6 times a
day. Then, the pupil of the eye is contracted with 1% pilocarpine
drops, administered for example at 15-minute intervals, starting 45
minutes before surgery. Drops (such as NSAID drops) are
administered 2 times before surgery to minimize inflammation.
[0044] General anesthesia can be performed on the patient, but
local anesthesia is preferred. For local anesthesia, 2% lidocaine
with 7.5 U/ml hyaluronidase can be given 10 minutes before surgery.
Orbital compression is applied to make the eye soft and to reduce
orbital pressure.
[0045] For preparation of the surgical field, the periorbital skin
of the patient is painted with iodine, then 5% povidine is applied.
5% povidine is also applied two-three times to the lid margin and
the conjunctival fornices. Then, the eye is washed with saline.
[0046] An eye speculum is used for exposure of the surgical field.
Upper and lower lid sutures, as well as superior rectus sutures can
be applied in place of the speculum. (A sutureless procedure can
also be used.) Adhesive plastic, applied to the surface of the
eyelids, is used to pull the eyelashes.
[0047] For making small intraoperative incisions, an side port (for
example, 0.6 mm) is made in the anterior chamber. This injection is
started at the opposite limbus. As the aqueous fluid drains, it is
replaced, for example, with a viscoelastic agent. The depth of the
anterior chamber is not reduced at any time.
[0048] In one embodiment, for implantation of the intraocular lens
assembly of the invention into the eye, two side ports are made to
introduce the instruments that are used to fix the iris to the
haptics. The width of the incision depends on the diameter of the
intraocular lens assembly of the invention (being, for example, 4-5
mm). The incision may be made at the limbus or in the clear cornea.
If a pocket section is made, wound closure (see, below) can be made
without sutures. The intraocular lens assembly of the invention can
then be introduced in the pre-crystalline space with angled-suture
forceps the lens is positioned, for example, behind the iris on a
horizontal axis with a cyclodialysis spatula. The intraocular lens
assembly of the invention is then manipulated to center the optic
on the pupil. During implantation of the phakic intraocular lens
assembly of the invention into the anterior chamber, the lens is
centered and fixed so that it does not slip out of position. The
lens can be positioned between the cornea and the iris, but
avoiding contact with either to prevent corneal damage,
proliferation of corneal epithelium on the anterior surface of the
lens causing opacification, or iris. If the lens is not positioned
properly with respect to the pupil, too much light may be admitted
to the retina, causing serious vision difficulties. The haptics
generally lodge in the angle of the anterior chamber. Also, the
anterior chamber of the eye is filled with the aqueous humor, a
fluid secreted by the ciliary process, passing from the posterior
chamber to the anterior chamber through the pupil, and from the
angle of the anterior chamber it passes into the spaces of Fontana
to the pectinate villi through which it is filtered into the venous
canal of Schlemm. The implanted lens is positioned so the flow of
fluid is not blocked.
[0049] After the intraocular lens assembly of the invention is
implanted, the viscoelastic material (if previously introduced into
the eye chambers) is removed from the anterior and posterior
chambers of the eye with an aspiration syringe (such as a 24-gauge
cannula). The intraocular lens assembly of the invention is fixed
to the anterior surface of the iris by the haptics of the lens. To
achieve fixation, the haptic holds a fold of the iris on either
side of the pupil. The anterior chamber is washed thoroughly with
saline. The pupil is contracted with intraocular acetylcholine 1%,
carbachol 0.01%, or pilocarpine 0.5% solution. The incision is
closed by hydrating the corneal incisions. A suture rarely is
needed.
[0050] In another embodiment, for implantation of the intraocular
lens assembly of the invention, the main incision is made at the
ventral area of the eye (at the "top" of the eye, at "12 o'clock").
The width is preferably equal to the size of the optic, which may
be 4-5 mm. Side incisions are made, approximately 1 mm wide. The
lens assembly of the invention is inserted then vertically. The
lens assembly of the invention is rotated inside the
viscoelastic-filled anterior chamber; the haptics are placed
horizontally.
[0051] Fixating the lens assembly of the invention is a bimanual
procedure. Lens assemblies are implanted using special tools to
compress the haptics, such as forceps or cannulae, or rely on
microhooks to manipulate the optic through a hole in the surface of
the optic (see discussion in U.S. Pat. No. 6,142,999). A
vertically-holding lens forceps, which enters the anterior chamber
through the main incision, centers the optic on the pupil and holds
it steadily. A thin forceps is introduced from the side incision
and grasps the iris close to the claw, passing a fold of the iris
through the claw, and results in fixing one of the haptics. Both
instruments are withdrawn, and the surgeon changes hands for
holding each tool. The anterior chamber of the eye is again
deepened with viscoelastic material, and the lens-fixation
instruments are reintroduced. The second haptic-fixation maneuver
is performed through the incision on the opposite side.
[0052] A peripheral iridectomy can then be performed. Then, the
introduced viscoelastic material (if any) is aspirated through the
three incisions. The anterior chamber is gently irrigated and
inflated with air to remove all viscoelastic material.
[0053] For closure of the incision line, the apposition of the
sides of the incision may be achieved by one or two superficial
sutures. Alternatively, a large air bubble may be left inside the
anterior chamber to effect an apposition. If the limbal incision
was made without a pocket, then a closure of the incision line
should be performed using sutures.
[0054] At the end of the surgery, 20 mg of gentamycin and 2 mg of
dexamethasone are subconjunctivally injected. A sterile pad and a
protective shield are applied.
[0055] Alternatively, the intraocular lens assembly of the
invention can be located in the posterior chamber of the eye, using
methods known to those of skill in the ophthalmic art (see, U.S.
Pat. No. 6,110,202; Pesando et al., 15(4) J. Refract Surg. 415-23
(1999); Sanders et al., 15(3) J. Refract Surg 309-15 (1999). In
posterior chamber implants, the haptics normally lodge in the
ciliary sulcus.
[0056] Aphakic intraocular lens assembly implantation is also
usefully provided for by the intraocular lens assembly of the
invention. The lens assembly can be surgically implanted in the
evacuated capsular bag of the lens of an eye (for example, through
the anterior capsule opening in the bag) in a position such that
the lens optic of the intraocular lens assembly is aligned with the
opening defined by the anterior capsular remnant, and the outer
ends of the lens distal portions are disposed within the outer
perimeter of the bag. The intraocular lens assembly of the
invention has a radial dimension from the outer end of each distal
or extended portion to the axis of the intraocular lens assembly.
Thus, with the intraocular lens assembly implanted within the
capsular bag, the outer ends of the extended portions engage the
inner perimetrical wall of the capsular bag with no or minimal
stretching of the bag. After implantation of the intraocular lens
assembly in the capsular bag, active ectodermal cells on the
posterior surface of the anterior capsule rim of the bag cause
fusion of the rim to the elastic posterior capsule of the bag by
fibrosis about the lens extended portions. Because of the haptic
design, the intraocular lens assembly of the invention can, when
placed in the capsular bag of the eye, provide accommodation for
the patient.
[0057] Advantageously, post-operative atropinization of the optic
ciliary muscle is not required for the intraocular lens assembly of
the invention (when implanted either as a refractive phakic
intraocular lens or an aphakic intraocular lens) to achieve
accommodation. During surgery, especially for implantation of
aphakic intraocular lenses, the ciliary muscle of the eye had
previously and typically been paralyzed with a ciliary muscle
relaxant to place the muscle in its relaxed state. Ciliary muscle
relaxants include anticholinergics such as atropine, scopolamine,
homatropine, cyclopentolate and tropicarnide. Atropine is
preferred. Proprietary preparations of atropine include Isopto
Atropine (eye drops); Minims Atropine Sulphate (single-dose eye
drops); Min-I-Jet Atropine (injection); Actonorm Powder (combined
with antacids and peppermint oil); Atropine-1; Atropine-Care;
Atropisol; Isopto Atropine; Ocu-tropine; Atropair; Atropine Sulfate
S.O.P.; Atrosulf; I-Tropine; Isopto Atropine; and Ocu-Tropine.
Prior to this invention (i.e., while implanting intraocular lenses
not having the advantages of the foldable intraocular lens assembly
of the invention), the patient's eye would be atropinized following
surgery, to allow for accommodation of the lens of the implanted
aphakic intraocular lens assembly to the eye (see discussion, U.S.
Pat. No. 6,051,024). Following surgery, the ciliary muscle relaxant
(such as atropine) would be periodically introduced throughout a
post-operative fibrosis and healing period (such as two to three
weeks) to maintain the ciliary muscle in its relaxed state until
fibrosis was complete. This drug-induced relaxation of the ciliary
muscle prevented contraction of the ciliary muscle and immobilized
the capsular bag. Thus, the implanted intraocular lens optic fixed
during fibrosis in its distant vision position within the eye
relative to the retina (accommodation). The implanted lens pressed
backward against and thereby forwardly stretched the elastic
posterior capsule of the capsular bag. By contrast, because of the
haptic design of the intraocular lens assembly of the invention,
the lens can, when placed in the capsular bag of the eye, provide
accommodation for the patient without the administration of
post-operative atropinc.
[0058] In another form of the present invention, there is also
provided a method for implanting an intraocular lens assembly in an
eye which provides accommodation. This includes the insertion of an
intraocular lens (IOL) assembly into the eye, where the IOL
assembly extends along an optical axis between an anterior optical
surface and a posterior optical surface. The lens has a
circumferential edge disposed about an optical axis at a junction
of the anterior and posterior optical surfaces. The lens further
includes N haptics where n is an integer greater than 1. Each
haptic extends from an associated portion of the circumferential
edge and along associated haptic axis. Each of the haptics is
loop-like or paddle-like and extends between end portions at
opposite ends thereof. The end portions are joined to the lens at
the circumferential edge. Also, the haptic axis is angulated away
from anterior surface by angle A with respect to a plane transverse
to optical axis. In one embodiment, angle A may be in an
approximate range of 4-7 degrees.
[0059] It will be apparent to those skilled in the art that other
changes and modifications can be made in the above-described
invention and methods for making and using the same, without
departing from the scope of the invention herein, and it is
intended that all matter contained in the above description shall
be interpreted in an illustrative and not in a limiting sense.
* * * * *
References