U.S. patent application number 10/413763 was filed with the patent office on 2003-09-25 for foldable intraocular lenses with highly flexible optic and rigid fixation members.
This patent application is currently assigned to Allergan Sales, Inc.. Invention is credited to Brady, Daniel G..
Application Number | 20030181977 10/413763 |
Document ID | / |
Family ID | 25479847 |
Filed Date | 2003-09-25 |
United States Patent
Application |
20030181977 |
Kind Code |
A1 |
Brady, Daniel G. |
September 25, 2003 |
Foldable intraocular lenses with highly flexible optic and rigid
fixation members
Abstract
An intraocular lens having an ultrathin and highly pliable optic
and relatively more rigid fixation members extending outward
therefrom. The optic desirably includes a flange to which a common
arm of a pair of joined fixation members attaches. The fixation
members extend on opposite sides of the optic in U-shaped flex
portions spanning a distance larger than the diameter of the optic.
The fixation members may be flexed inward so as to overlap within
the diameter of the optic and define an insertion profile of less
than about 5 mm. For anterior implantation, four relatively evenly
circumferentially spaced pods are provided by the pair of fixation
members. The optic center desirably has a thickness of less than
about 0.5 mm for meniscus type optics, and may be made of silicone,
hydrophilic acrylic, or hydrophobic acrylic. The fixation members
have a thickness of about 0.25 mm and are desirably made of poly
methyl methacrylate (PMMA) or polyether sulfone. The arm common to
the fixation members extends radially inward to the flange and is
attached thereto by heat staking, laser welding, or ultrasonic
welding, preferably using a separate coupling member. The coupling
member may be made of the same material as the arm and desirably
has a projection that fits through an aperture in the flange and
directly contacts a portion of the arm for a more secure bond.
Inventors: |
Brady, Daniel G.; (San Juan
Capistrano, CA) |
Correspondence
Address: |
STOUT, UXA, BUYAN & MULLINS LLP
4 VENTURE, SUITE 300
IRVINE
CA
92618
US
|
Assignee: |
Allergan Sales, Inc.
Irvine
CA
|
Family ID: |
25479847 |
Appl. No.: |
10/413763 |
Filed: |
April 15, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10413763 |
Apr 15, 2003 |
|
|
|
09943549 |
Aug 30, 2001 |
|
|
|
Current U.S.
Class: |
623/6.46 ;
623/6.43; 623/6.49 |
Current CPC
Class: |
A61F 2002/1683 20130101;
A61F 2/1616 20130101; A61F 2002/169053 20150401; A61F 2/16
20130101; A61F 2002/1686 20130101 |
Class at
Publication: |
623/6.46 ;
623/6.49; 623/6.43 |
International
Class: |
A61F 002/16 |
Claims
What is claimed is:
1. A foldable intraocular lens for implantation in the eye, the
intraocular lens comprising: an optic centered on an optical axis
and made of a highly pliable material, the optic having a generally
circular periphery and an integral flange extending radially
outward therefrom; a cantilevered arm extending radially outward
from the periphery of the optic made of a material that is flexible
but more rigid than the material of the optic, the arm being
attached to the optic; and a pair of fixation members integral with
the cantilevered arm for supporting the optic centered on the
optical axis of the eye, each fixation member having a proximal end
at the outer end of the cantilevered arm, a distal end, and a flex
portion intermediate the proximal and distal ends, wherein the flex
portions extend generally away from one another adjacent to their
respective proximal ends on diametrically-opposed sides of the
optic.
2. The intraocular lens of claim 1, wherein the material of the
optic is selected from the group consisting of: silicone;
hydrophilic acrylic; and hydrophobic acrylic.
3. The intraocular lens of claim 2, wherein the material of the
cantilevered arm and fixation members is selected from the group
consisting of: PMMA; and polyether sulfone.
4. The intraocular lens of claim 1, wherein the optic is a meniscus
type of optic and has a center thickness of less than about 0.5
mm.
5. The intraocular lens of claim 1, wherein the fixation members
have a thickness and flexibility that enables them to be folded
inward toward one another so as to overlap the optic and present a
smaller insertion profile than the diameter of the optic.
6. The intraocular lens of claim 1, wherein the cantilevered arm
includes a main elongate portion and a paddle that overlaps one
side of the flange, the intraocular lens further including: a
coupling member separate from the optic and cantilevered arm, the
coupling member including a portion that overlaps the flange on the
side opposite the paddle, and a stepped edge that has approximately
the same thickness as the flange, the coupling member and paddle
sandwiching the flange therebetween and the stepped edge of the
coupling member directly contacting the cantilevered arm, wherein
the cantilevered arm, flange, and coupling member define an
attachment assembly, the assembly being bonded together.
7. The intraocular lens of claim 6, wherein the assembly is bonded
together using a method selected from the group consisting of: heat
staking; laser welding; and ultrasonic welding.
8. The intraocular lens of claim 1, wherein the cantilevered arm
and flange are attached together using a method selected from the
group consisting of: heat staking; laser welding; and ultrasonic
welding.
9. The intraocular lens of claim 1, wherein the flex portions of
each fixation member extend generally away from one another
adjacent to their respective proximal ends and then turn about 90
degrees to form substantial U-shapes that have lengths greater than
the diameter of the optic, the U-shapes being oriented generally in
parallel on diametrically-opposed sides of the optic.
10. The intraocular lens of claim 9, wherein the lens is adapted
for anterior chamber implantation and each flex portion of each
fixation member includes a pair of spaced apart pods for contacting
the iridio-corneal angle in the anterior chamber.
11. The intraocular lens of claim 10, wherein each pair of pods is
spaced apart at least seven mm.
12. The intraocular lens of claim 1, wherein the lens is adapted
for anterior chamber implantation and each flex portion of each
fixation member includes a pair of spaced apart pods for contacting
the iridio-corneal angle in the anterior chamber, wherein the four
pods are arranged on the flex portions so that upon inward
compression of between about 0.5-1.5 mm, they form a square in the
iridio-corneal angle so as to reduce the chance of pupil
ovalization.
13. A foldable intraocular lens for implantation in the eye, the
intraocular lens comprising: an optic centered on an optical axis
and made of a highly pliable material, the optic having a generally
circular periphery; a cantilevered arm extending radially outward
from the optic periphery made of a material that is flexible but
more rigid than the material of the optic, the arm being attached
to the optic periphery using a method selected from the group
consisting of: heat staking; laser welding; and ultrasonic welding;
and a pair of fixation members integral with the cantilevered arm
for supporting the optic centered on the optical axis of the eye,
each fixation member having a proximal end at the outer end of the
cantilevered arm, a distal end, and a flex portion intermediate the
proximal and distal ends, the flex portions being oriented
generally in parallel on diametrically-opposed sides of the
optic.
14. The intraocular lens of claim 13, wherein the fixation members
have a thickness and flexibility that enables them to be folded
inward toward one another so as to overlap the optic and present a
smaller insertion profile than the diameter of the optic.
15. The intraocular lens of claim 13, wherein the optic has an
integral flange extending radially outward therefrom, and the
cantilevered arm includes a main elongate portion and a paddle that
overlaps one side of the flange, the intraocular lens further
including: a coupling member separate from the optic and
cantilevered arm, the coupling member including a portion that
overlaps the flange on the side opposite the paddle and a stepped
edge that has approximately the same thickness as the flange, the
coupling member and paddle sandwiching the flange therebetween and
the stepped edge of the coupling member directly contacting the
cantilevered arm, wherein the cantilevered arm, flange, and
coupling member define an attachment assembly, the assembly being
bonded together using the aformentioned methods.
16. The intraocular lens of claim 13, wherein the flex portions of
each fixation member extend generally away from one another
adjacent to their respective proximal ends and then turn about 90
degrees to form substantial U-shapes that have lengths greater than
the diameter of the optic, the U-shapes being oriented generally in
parallel on diametrically-opposed sides of the optic.
17. The intraocular lens of claim 16, wherein the lens is adapted
for anterior chamber implantation and each flex portion of each
fixation member includes a pair of spaced apart pods for contacting
the iridio-corneal angle in the anterior chamber.
18. The intraocular lens of claim 17, wherein each pair of pods is
spaced apart at least seven mm.
19. The intraocular lens of claim 13, wherein the lens is adapted
for anterior chamber implantation and each flex portion of each
fixation member includes a pair of spaced apart pods for contacting
the iridio-corneal angle in the anterior chamber, wherein the four
pods are arranged on the flex portions so that upon inward
compression of between about 0.5-1.5 mm, they form a square in the
iridio-corneal angle so as to reduce the chance of pupil
ovalization.
20. A foldable intraocular lens for implantation in the eye, the
intraocular lens comprising: an optic centered on an optical axis
and made of a highly pliable material, the optic having a generally
circular periphery and an integral flange extending radially
outward therefrom; a fixation member for supporting the optic
centered on the optical axis of the eye, the fixation member having
a proximal end, a distal end, and a flex portion intermediate the
proximal and distal ends, the proximal end having an arm extending
toward the optic and a paddle on the end thereof that overlaps the
flange and is connected thereto; and a coupling member separate
from the optic and fixation member and including a portion that
overlaps the flange, and a stepped edge that has approximately the
same thickness as the flange, the coupling member and paddle
sandwiching the flange therebetween and the stepped edge of the
coupling member directly contacting the arm, wherein the arm,
flange, and coupling member define an attachment assembly, the
assembly being bonded together.
21. The intraocular lens of claim 20, wherein the material of the
optic is selected from the group consisting of: silicone;
hydrophilic acrylic; and hydrophobic acrylic.
22. The intraocular lens of claim 21, wherein the fixation member,
arm and paddle are integrally formed of a material that is flexible
but more rigid than the material of the optic.
23. The intraocular lens of claim 22, wherein the material of the
arm and fixation members is selected from the group consisting of:
PMMA; and polyether sulfone.
24. The intraocular lens of claim 20, wherein the optic is a
meniscus type of optic and has an edge thickness of less than about
0.5 mm.
25. The intraocular lens of claim 20, wherein there are a pair of
fixation members integral with the arm for supporting the optic
centered on the optical axis of the eye, and wherein the flex
portions are oriented generally in parallel on
diametrically-opposed sides of the optic.
26. The intraocular lens of claim 25, wherein the flex portions of
each fixation member extend generally away from one another
adjacent to their respective proximal ends and then turn about 90
degrees to form substantial U-shapes that have lengths greater than
the diameter of the optic, the U-shapes being oriented generally in
parallel on diametrically-opposed sides of the optic.
27. The intraocular lens of claim 20, wherein the attachment
assembly is bonded together using a method selected from the group
consisting of: heat staking; laser welding; and ultrasonic
welding.
28. The intraocular lens of claim 20, wherein the flange includes
an aperture and coupling member has a projection that fits through
the aperture and contacts the paddle on the other side of the
flange.
29. The intraocular lens of claim 20, wherein the fixation member
arm and paddle and coupling member are made of the same material,
and the attachment assembly is bonded together using heat such that
the portions in direct contact fuse together.
30. A method of folding and inserting an intraocular lens in an
eye, comprising: providing an intraocular lens having: an optic
centered on an optical axis and made of a highly pliable material,
the optic having a generally circular periphery; a cantilevered arm
extending radially outward from the optic periphery made of a
material that is flexible but more rigid than the material of the
optic, the arm being bonded to the optic periphery; and a pair of
fixation members integral with the cantilevered arm for supporting
the optic centered on the optical axis of the eye, each fixation
member having a proximal end at the outer end of the cantilevered
arm, a distal end, and a flex portion intermediate the proximal and
distal ends, the flex portions being oriented generally in parallel
on diametrically-opposed sides of the optic; flexing both of the
fixation members toward one another so that they overlap within the
diameter of the optic and define an insertion profile of less than
about 5 mm; and passing the intraocular lens with the fixation
members overlapping one another through an incision in the cornea
of 5 mm or less without otherwise manipulating the optic into a
fold.
31. The method of claim 30, wherein the flex portions are oriented
generally in parallel on diametrically-opposed sides of the optic,
and the flex portions of each fixation member extend generally away
from one another adjacent to their respective proximal ends and
then turn about 90 degrees to form substantial U-shapes that have
lengths greater than the diameter of the optic, the U-shapes being
oriented generally in parallel on diametrically-opposed sides of
the optic and having inner arms and outer arms, the method
including flexing both of the fixation members toward one another
so that the outer arms overlap the diameter of the optic.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to intraocular lenses (IOLs). More
particularly, the invention relates to foldable IOLs having highly
pliable optics and relatively less flexible haptics that may be
placed in either the anterior or posterior chamber of the eye
through very small incisions.
[0002] Intraocular lenses (IOLs) are commonly used to modify or
enhance vision. IOLs can be placed at various positions or
locations within the eye. For example, IOLs can be placed in the
anterior chamber (AC) of the eye, that is, the region of the eye
posterior of the cornea and anterior of the iris. Alternatively, a
posterior chamber (PC) IOL is implanted behind the iris, typically
in the capsular bag from which the natural lens has been
removed.
[0003] IOLs advantageously have been foldable for insertion through
small incisions (less than about 6 mm), particularly for insertion
in the capsular bags in the posterior chamber of the eye. IOLs may
generally be classed by material. Hard or rigid IOLs are
distinguished from soft IOLs that may be folded to facilitate
implantation through a small incision in the cornea (and capsular
bag for posterior lenses).
[0004] A typical IOL has a disk-shaped optic with 2 to 4 fixation
members extending outward therefrom. For purpose of orientation,
3:00, 6:00, 9:00, and 12:00 positions around the optic may be
defined, thus locating perpendicular 3/9 o'clock and 6/12 o'clock
axes. As a matter of convention, a three-piece IOL (i.e., an optic
and 2 haptics) is oriented along the 6/12 o'clock axis such that
the haptics project outward generally along that axis (so that the
haptics are often opposite mirror images of one another across the
3/9 o'clock axis). Four- or five-piece IOLs are oriented likewise.
Such IOLs are normally introduced through the incision using a
Bartell-style injector, for example as described in Bartell U.S.
Pat. No. 4,681,102, the disclosure of which is hereby incorporated
herein in its entirety by reference.
[0005] A Bartell-style injector folds the optic along the 6/12
o'clock axis, thus defining leading and trailing haptics. The
profile of the haptics along the 3/9 o'clock axis is less than
about 6 mm so as to fit through small incisions. This means that
either a single haptic has a length dimension of less than about 6
mm or that the outermost portions of two haptics are spaced apart
less than about 6 mm. Unfortunately, this size limitation reduces
the implanted stability of the IOL, increases forces transmitted to
the optic which may increase optic displacement, hinders symmetric
placement of the IOL within the capsular bag in PC implants, and
potentially increase the severity and occurrence of pupil
ovalization in anterior chamber implants.
[0006] IOLs may be oversized relative to the peripheral anatomical
structure and flexible in the plane of the IOL such that they are
placed in compression when implanted. Both soft and rigid IOLs
exert retention forces on their outer ends that are desirable so
that the lens is held in place or centered, otherwise a loose fit
might cause vision and other problems. However, a balance must be
observed between sufficient compression for a good fit and
excessive compression that adversely affects the IOL performance.
For example, problems of corneal touch and further endothelial cell
loss may arise in some current anterior chamber IOLs, whether
formed of soft or rigid materials, which may deflect along the
optical axis even with only a small magnitude of compressive
fit.
[0007] A common technique for placement of an intraocular lens in
the anterior chamber is within the iridio-corneal angle, in a
so-called "angle-supported" configuration. A number of non-foldable
angle-supported anterior chamber intraocular lenses are fabricated
from rigid materials, such as polymethyl methacrylate (PMMA). These
rigid anterior chamber intraocular lenses are typically based upon
a Kelman design of thin, flexible haptics or fixation members with
3 or 4 footplates or pods. Unfortunately, some designs provide less
than desirable foldability, or else have minimal compressive
retention forces that permits unwanted intraocular lens
movement.
[0008] It would be advantageous to provide foldable IOLs which
provide one or more of the following: reduced incidences of one or
more known complications caused by prior anterior chamber IOLs,
effective and safe folding for insertion in the eye, safe and
effective fit to a range of sizes of eyes, a minimum of
translational movement of the optic of the IOL along the optical
axis from the compressive fit in the eye, and an otherwise stable
optic to avoid unwanted movement.
SUMMARY OF THE INVENTION
[0009] New IOLs for implantation in eyes have been discovered. The
present IOLs, are sized and structured to reduce the incidence of
one or more known complications in the eye caused by prior
IOLs.
[0010] The present invention provides a foldable intraocular lens
for implantation in the eye, comprising an optic centered on an
optical axis and made of a highly pliable material, the optic
having a generally circular periphery and an integral flange
extending radially outward therefrom. A cantilevered arm extends
radially outward from the periphery of the optic and is made of a
material that is flexible but more rigid than the material of the
optic, the arm being attached to the optic. A pair of fixation
members integral with the cantilevered arm support the optic
centered on the optical axis of the eye. Each fixation member has a
proximal end at the outer end of the cantilevered arm, a distal
end, and a flex portion intermediate the proximal and distal ends.
The flex portions extend generally away from one another adjacent
to their respective proximal ends on diametrically-opposed sides of
the optic.
[0011] Desirably, the material of the optic is selected from the
group consisting of, silicone, hydrophilic acrylic, and hydrophobic
acrylic. The material of the cantilevered arm and fixation members
may being selected from the group consisting of PMMA, and polyether
sulfone. If the optic is a meniscus type of optic its desirably has
a center thickness of less than about 0.5 mm. The fixation members
preferably have a thickness and flexibility that enables them to be
folded inward toward one another so as to overlap the optic and
present a smaller insertion profile than the diameter of the
optic.
[0012] The cantilevered arm may include a main elongate portion and
a paddle that overlaps one side of the flange, and the intraocular
lens further includes a coupling member separate from the optic and
cantilevered arm. The coupling member preferably includes a portion
that overlaps the flange on the side opposite the paddle, and a
stepped edge that has approximately the same thickness as the
flange. The coupling member and paddle sandwich the flange
therebetween and the stepped edge of the coupling member directly
contacts the cantilevered arm, wherein the cantilevered arm,
flange, and coupling member define an attachment assembly that is
bonded together. The attachment assembly is preferably bonded
together using a method selected from the group consisting of heat
staking, laser welding, and ultrasonic welding.
[0013] The flex portions of each fixation member may extend
generally away from one another adjacent to their respective
proximal ends and then turn about 90 degrees to form substantial
U-shapes that have lengths greater than the diameter of the optic,
the U-shapes being oriented generally in parallel on
diametrically-opposed sides of the optic. When the lens is adapted
for anterior chamber implantation, each flex portion of each
fixation member includes a pair of spaced apart pods for contacting
the iridio-corneal angle in the anterior chamber. Each pair of pods
is desirably spaced apart at least seven mm. When the lens is
adapted for anterior chamber implantation, each flex portion of
each fixation member includes a pair of spaced apart pods for
contacting the iridio-corneal angle in the anterior chamber. The
four pods are desirably arranged on the flex portions so that upon
inward compression of between about 0.5-1.5 mm, they form a square
in the iridio-corneal angle so as to reduce the chance of pupil
ovalization.
[0014] A further aspect of the present invention is a foldable
intraocular lens for implantation in the eye, comprising an optic
centered on an optical axis and made of a highly pliable material,
the optic having a generally circular periphery. A cantilevered arm
extends radially outward from the optic periphery and is made of a
material that is flexible but more rigid than the material of the
optic, the arm is attached to the optic periphery using a method
selected from the group consisting of, heat staking, laser welding,
and ultrasonic welding. A pair of fixation members integral with
the cantilevered arm support the optic centered on the optical axis
of the eye. Each fixation member has a proximal end at the outer
end of the cantilevered arm, a distal end, and a flex portion
intermediate the proximal and distal ends, the flex portions being
oriented generally in parallel on diametrically-opposed sides of
the optic. Desirably, the fixation members have a thickness and
flexibility that enables them to be folded inward toward one
another so as to overlap the optic and present a smaller insertion
profile than the diameter of the optic.
[0015] In a still further aspect, a foldable intraocular lens for
implantation in the eye is provided. The intraocular lens includes
an optic centered on an optical axis and made of a highly pliable
material, the optic having a generally circular periphery and an
integral flange extending radially outward therefrom. A fixation
member supports the optic centered on the optical axis of the eye,
the fixation member having a proximal end, a distal end, and a flex
portion intermediate the proximal and distal ends, the proximal end
having an arm extending toward the optic and a paddle on the end
thereof that overlaps the flange and is connected thereto. A
coupling member separate from the optic and fixation member
includes a portion that overlaps the flange, and a stepped edge
that has approximately the same thickness as the flange. The
coupling member and paddle sandwich the flange therebetween and the
stepped edge of the coupling member directly contacts the arm,
wherein the arm, flange, and coupling member define an attachment
assembly, the assembly being bonded together.
[0016] The fixation member, arm and paddle may being integrally
formed of a material that is flexible but more rigid than the
material of the optic. Desirably, the material of the arm and
fixation members is selected from the group consisting of PMMA and
polyether sulfone. The attachment assembly is preferably bonded
together using a method selected from the group consisting of, heat
staking, laser welding, and ultrasonic welding. The flange may
include an aperture and the coupling member has a projection that
fits through the aperture and contacts the paddle on the other side
of the flange. Preferably, the fixation member arm and paddle and
coupling member are made of the same material, in the attachment
assembly is bonded together using heat such that the portions in
direct contact fuse together.
[0017] In accordance with present invention, a method of folding
and inserting an intraocular lens in an eye comprises:
[0018] providing an intraocular lens having:
[0019] an optic centered on an optical axis and made of a highly
pliable material, the optic having a generally circular
periphery;
[0020] a cantilevered arm extending radially outward from the optic
periphery made of a material that is flexible but more rigid than
the material of the optic, the arm being bonded to the optic
periphery; and
[0021] a pair of fixation members integral with the cantilevered
arm for supporting the optic centered on the optical axis of the
eye, each fixation member having a proximal end at the outer end of
the cantilevered arm, a distal end, and a flex portion intermediate
the proximal and distal ends, the flex portions being oriented
generally in parallel on diametrically-opposed sides of the
optic;
[0022] flexing both of the fixation members toward one another so
that they overlap within the diameter of the optic and define an
insertion profile of less than about 5 mm; and
[0023] passing the intraocular lens with the fixation members
overlapping one another through an incision in the cornea of 5 mm
or less without otherwise manipulating the optic into a fold.
[0024] The flex portions are desirably oriented generally in
parallel on diametrically-opposed sides of the optic, and the flex
portions of each fixation member extend generally away from one
another adjacent to their respective proximal ends and then turn
about 90 degrees to form substantial U-shapes that have lengths
greater than the diameter of the optic, the U-shapes being oriented
generally in parallel on diametrically-opposed sides of the optic
and having inner arms and outer arms. The method of thus includes
flexing both of the fixation members toward one another so that the
outer arms overlap the diameter of the optic.
[0025] These and other aspects and advantages of the present
invention will become apparent in the following detailed
description and claims, particularly when considered in conjunction
with the accompanying drawings in which like parts bear like
reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a plan view of an optic of the intraocular lens of
the present invention;
[0027] FIG. 2 is a plan view of an exemplary intraocular lens of
the present invention;
[0028] FIG. 2A is a plan view of an alternative intraocular lens of
the present invention;
[0029] FIG. 3 is a perspective view of a portion of the intraocular
lens of the present invention showing an area of attachment between
the optic and a cantilevered arm extending outward therefrom;
[0030] FIG. 4 is a perspective view of the underside of a coupling
member used to attach the optic to the cantilevered arm; and
[0031] FIG. 5 is a plan view of the intraocular lens of present
invention shown folded in a manner that facilitates implantation
through a relatively small incision in the eye.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The present invention provides intraocular lenses having
flexible optic portions enabling folding, and relatively more rigid
fixation members or haptics for sufficient and symmetric fixation
force.
[0033] The present invention provides an intraocular lens that is
suitable for implantation in either the anterior or posterior
chambers of the eye. In general, lenses of the present invention
include ultrathin and highly pliable optics and relatively more
rigid haptics, and are suitable for introduction through extremely
small incisions in the cornea and in the capsular bag. Lenses of
the present invention may be implanted in the eye using
conventional injectors (i.e., Bartell-style injectors), or using
forceps, or other similar expedient. Various materials may be used
in the construction of the lenses described herein, and any
particularly preferred construction should not be considered
necessarily limiting.
[0034] FIG. 1 illustrates an optic 24 used in an intraocular lens
22 of the present invention as seen in FIG. 2. The optic 20 is
generally disk-shaped having a circular periphery 24 centered about
an optical axis OA. In addition, a small flange 26 projects
outwardly from the periphery 24, and is desirably integrally formed
therewith such as by molding from a homogeneous material. The
flange 26 may take a variety of forms, and is shown having a
generally trapezoidal shape in plan view extending from the three
o'clock position on the optic 20. An alternative flange
configuration is seen in FIG. 3. The flange 26 desirably includes
an aperture 28 therein, to assist in bonding fixation members
(described below) to the optic 20.
[0035] The optic 24 may be bi-convex, concave-convex (meniscus
type), plano-convex, or concave-concave, and have optical powers of
between -15 to +30. Again, the optic 20 may be made of a variety of
materials, although highly pliable materials such as silicone,
hydrophilic acrylic, or hydrophobic acrylic are preferred. Lenses
of the present invention have optics that fold and fit through
relatively small incisions (less than 5 mm in length).
Advantageously, the optics are so thin that they need not be
pre-folded before advancing through the incision, but rather
inherently fold as they are pushed through the incision, without
harming the corneal or capsular bag tissue. Importantly, such thin
lenses have not previously been made with the optic separate from
the fixation members, but have instead been molded or machined from
a single piece.
[0036] Quantification of the thickness dimension of the lenses
depends on the shape, be it bi-convex, concave-convex (meniscus
type), etc, and the diopter power, among other factors. For the
concave-convex (meniscus type) of lenses, which are typically
favored in the anterior chamber, having negative Diopter values,
the optic 20 has a minimum center thickness in the axial direction
of between 0.0762 mm to 0.127 mm (0.003-0.005 inches). Therefore,
for meniscus type optics, the center thickness may be as small as
about 0.13 mm, desirably around 0.1 mm. The edge thickness of such
ultra thin meniscus type optics is about 4 mm. Meniscus type optics
of the present invention have a maximum center thickness (for
optics having Diopter powers of 5 or 6) of less than about 0.5 mm.
Bi-convex optics of the present invention, in contrast, have a
center thickness of around 1.0 mm, and an edge thickness of less
than about 0.1 mm.
[0037] The intraocular lens 22 seen in FIG. 2 in its relaxed,
uncompressed state, includes the aforementioned optic 20 and a pair
fixation members 30a, 30b adapted to support the optic in the
center of the eye (whether placed in the anterior chamber, or in
the capsular bag in the posterior chamber). For purpose of
orientation, perpendicular axes 32, 34 along the horizontal and
vertical planes, respectively, are shown. Stated another way, the
horizontal axis 32 extends along the 3/9 o'clock plane, while the
vertical axis 34 extends along the 6/12 o'clock plane.
[0038] Desirably, the fixation members 30a, 30b are formed in a
single piece connected at their proximal ends 36a, 36b to the
flange 26 via a cantilevered arm 38. In an exemplary embodiment,
the fixation members 30a, 30b and cantilevered arm 38 are
integrally formed such as by molding from a homogeneous material
that is more rigid than that of the optic 20, although still
somewhat flexible to enable folding during implantation (described
below). Preferred materials are poly methyl methacrylate (PMMA) or
polyether sulfone, although other similar materials may be
used.
[0039] The flange 26 extends along the three o'clock direction, and
thus both of the fixation members 30a, 30b initially extend
generally vertically in opposite directions from the outermost end
of the cantilevered arm 38. From their proximal ends 36a, 36b, the
fixation members 30a, 30b each define an elongated, curvilinear
inside leg 40, a U-bend 42, and an outside leg 44 that terminates
at a distal end 46. The combination of the inside leg 40, U-bend
42, and outside leg 44 together define generally U-shaped flex
portions 50a, 50b, respectively, for each of the fixation members
30a, 30b.
[0040] Each of the U-shaped flex portions 50a, 50b has a
longitudinal dimension or depth, generally horizontally aligned in
FIG. 2, that is larger than the diameter of the optic 20. In other
words, the horizontal distance between the proximal end 36a, 36b
and the U-bend 42a, 42b in each fixation member 30a, 30b is longer
than the diameter of the optic 20. Indeed, in the relaxed state of
the IOL 22, the inside leg 40a, 40b of each of the fixation members
generally circumscribes the optic 20, covering an arc of
approximately 135 degrees. The outside leg 44a, 44b of each of the
fixation members is also arcuate, albeit in the opposite direction,
but generally traverses a horizontal line.
[0041] When implanted, the fixation members 30a, 30b compress
inward a slight amount, though not so much that the respective
elongate sections thereof touch each other or the optic. Because of
the elongated nature of each of the fixation members 30a, 30b, and
because of their indirect connection to the optic 20 via the
cantilevered arm 38 and flange 26, relatively little of the
compressive forces imparted by the eye are transferred to the
optic. This reduces bowing or axial displacement of the optic.
Further advantages of the configuration of the fixation members
30a, 30b will be described below with respect to FIG. 5.
[0042] Furthermore, due to the length of each of the flex portions
50a, 50b, a pair of outwardly directed footplates or pods 52, 54 is
spaced apart a relatively long distance in comparison to IOLs of
the prior art. In particular, the pods 52, 54 are spaced greater
than 6 mm apart, and preferably between 7 and 9 mm apart. There are
thus four pods 52, 54 in the exemplary embodiment generally evenly
circumferentially spaced around the optical axis OA. This increased
spacing and positioning provides increased stability to the
intraocular lens 22, lowers the forces imparted to the optic 20 via
the fixation members 30a, 30b which can be designed to decrease
optic displacement along the optical axis OA, facilitates symmetric
placement of a PC lens in the capsular bag, and potentially reduces
the severity and occurrence of pupil ovalization.
[0043] In addition, the four pods 52, 54 are arranged on the flex
portions 50a, 50b so that upon inward compression of between about
0.5-1.5 mm, the pods form a square in the iridio-corneal angle so
as to reduce the chance of pupil ovalization. Desirably, each pod
flexes inward about 1 mm, and the shape of the the fixation members
30a, 30b is such that the initially rectangular pod distribution as
shown (in the relaxed, unimplanted state of the IOL) converts to a
square. It should be noted that the relative movement of the two
flex portions 50a, 50b is greater than the relative movement of the
two pods 52, 54 on either flex portion, given their connection
along the respective outside legs 44a, 44b. Therefore, the
rectangular distribution of the pods 52, 54 (elongated along the
6/12 o'clock axis) converts to a square distribution upon
implantation.
[0044] Each outside leg 44a, 44b spans from a first pod 52a, 52b
adjacent the U-bend 42a, 42b to a second pod 54a, 54b at the distal
end 46a, 46b of the respective fixation member 30a, 30b. Each pod
52, 54 is formed by an enlarged cross-section (in plan view)
relative to the rest of the fixation member 30 and has an outer
face (not numbered) with rounded corners that is angled so as to
provide maximum comfort and stability to the patient. The outer
faces are desirably angled so as to be generally concentric about
the optical axis OA. That is, if the intraocular lens 22 is
implanted in the anterior chamber, the outer faces of the pods 52,
54 present relatively large cross-sectional surfaces that contact
the iridio-corneal angle. If the lens 22 is implanted in the
posterior chamber, the outer faces of the pods 52, 54 provide large
and symmetric surface area contact with the interior of the
capsular bag. Because of their relatively great spacing and
preferred outer face orientation, the combined four pods 52, 54
reduce irritation to the soft tissue of the iridio-corneal angle or
the capsular bag.
[0045] An alternative intraocular lens 22' seen in FIG. 2A in its
relaxed, uncompressed state, includes an optic 20' and a pair
fixation members 30a', 30b' adapted to support the optic in the
center of the eye (whether placed in the anterior chamber, or in
the capsular bag in the posterior chamber). Again, for purpose of
orientation, perpendicular axes 32', 34' along the horizontal and
vertical planes, respectively, are shown. The intraocular lens 22'
is in many ways similar to the lens 22 of FIG. 2, and like parts
will be denoted with the same numbers with the addition of a prime
(').
[0046] As the earlier embodiment, the fixation members 30a', 30b'
are desirably formed in a single piece connected at their proximal
ends 36a', 36b' to a flange 26' via a cantilevered arm 38'. In an
exemplary embodiment, the fixation members 30a', 30b' and
cantilevered arm 38' are integrally formed such as by molding from
a homogeneous material that is more rigid than that of the optic
20, although still somewhat flexible to enable folding during
implantation (described below). Preferred materials are poly methyl
methacrylate (PMMA) or polyether sulfone, although other similar
materials may be used. It should be understood that any aspects of
the invention described herein with respect to the earlier IOL 22
shown in FIG. 2 may apply to the alternative IOL 22' in FIG.
2A.
[0047] The flange 26' extends along the three o'clock direction,
and thus both of the fixation members 30a', 30b' initially extend
generally vertically in opposite directions from the outermost end
of the cantilevered arm 38'. From their proximal ends 36a', 36b',
the fixation members 30a', 30b' have elongated curvilinear legs
40a', 40b' defining flex portions of the IOL 22'. In contrast to
the earlier embodiment, there is no outside leg, and no U-shaped
flex portions.
[0048] The curvilinear legs 40a', 40b' have lengths that are
greater than 6 mm, and preferably between 7 and 9 mm. This length
provides increased stability to the intraocular lens 22', lowers
the forces imparted to the optic 20' via the fixation members 30a',
30b' which can be designed to decrease optic displacement along the
optical axis OA, facilitates symmetric placement of a PC lens in
the capsular bag, and potentially reduces the severity and
occurrence of pupil ovalization.
[0049] As mentioned above, the means of attaching the fixation
members 30a, 30b to the optic 20 reduces the transmission of
external forces on the fixation members to the optic. Indeed, the
nature of the attachment is such that the fixation members are
substantially decoupled from the optic. As seen in FIG. 2, the
proximal ends 36a, 36b of the fixation members 30a, 30b come
together at the outermost end of the cantilevered arm 38. The
cantilevered arm 38, in turn, extends radially inward toward the
optic 20 and attaches to the flange 26, as best seen in FIG. 3. It
should be noted that the flange 26 illustrated in FIG. 3 is
substantially rectangular in plan view, in contrast to the
trapezoidal shape of the flange shown in FIGS. 1 and 2, although
the structure and function is essentially the same.
[0050] As seen in FIG. 3, the cantilevered arm 38 has a main
portion 60 that has a similar dimension in the plan view as in the
axial direction, a paddle 62 that is relatively thin in the axial
direction and wide in plan view, and a transition region 64
therebetween. The paddle 62 contacts one face of the flange 26
across a relatively large proportion of the surface area of the
paddle. Indeed, as illustrated in FIG. 3, the rectangular flange 26
and paddle 62 have substantially the same width in the
circumferential direction of the optic 20. The entire length of the
cantilevered arm 38 including the main portion 60, transition
region 64 and paddle 62 is desirably less than about 2 mm.
[0051] An attachment assembly seen in FIG. 3 includes the
aforementioned flange 26, the paddle 62 of the cantilevered arm 38,
and a coupling member 70. These three elements bond together using
conventional means such as heat staking, laser welding, or
ultrasonic welding. The coupling member 70 includes a relatively
thin (in the axial dimension) and wide (in plan view) cover 72 that
contacts the opposite side of the flange 26 from the paddle 62. In
addition, the coupling member 70 includes an elongate step 74
projecting axially from the cover 72 that contacts the paddle
62.
[0052] The coupling member 70 is desirably made of the same
material as the cantilevered arm 38, or at least of a material that
easily and securely bonds thereto upon heat staking, laser welding,
or ultrasonic welding. When these three elements are heated, laser
welded, or ultrasonically welded, they join together to form a
composite structure that is relatively strong and can withstand the
forces associated with manipulation during implantation and the
forces associated with normal use after implantation. Contact
between the coupling member 70 and cantilevered arm 38 by virtue of
the step 74 ensures direct bonding between these two elements, and
effectively locks the flange 26 that is sandwiched therebetween in
place.
[0053] FIG. 4 illustrates the underside of the coupling member 70
that is juxtaposed against the flange 26 and cantilevered arm 38.
With reference back to FIG. 1, the flange 26 preferably includes an
aperture 28. A similarly shaped projection 76 is provided on the
underside of coupling member 70. Although not shown, the projection
76 fits closely within the aperture 28 and extends the same axial
distance as the step 74 so as to contact the paddle 62. After heat
staking, laser welding, or ultrasonic welding, this additional
direct contact between the coupling member 70 and cantilevered arm
38, which are made of the same or very similar materials, further
ensures a secure bond for the attachment assembly. Moreover, the
projection 76 extends directly through the flange 26, and provides
a positive anchor thereto. An enlarged window 78 seen in the middle
of coupling member 70 may be useful in the mold process of forming
the coupling member 70, but also serves the purpose of providing a
cavity into which the material of the flange 26 may expand during
the process of heat staking or ultrasonic welding.
[0054] It should be understood by those of skill in the art that
various configurations of the attachment assembly in keeping with
the principles of the present invention are envisioned. Indeed, the
cantilevered arm 38 may include a forked end that fits around the
flange 26, rather than providing a separate coupling member 70.
Likewise, the coupling member 70 may be in the form of a sleeve
that fits entirely around the juxtaposed flange 26 and cantilevered
arm 38. Any of the configurations in accordance with the present
invention enables attachment of relatively rigid fixation members
to an ultrathin optic 20.
[0055] FIG. 3 illustrates the optic periphery 24 (for a meniscus
type lens) that has a thickness of around 0.4 mm. The flange 26 has
an even smaller thickness, and the sandwiched attachment assembly
has about the same thickness as the optic 20. As seen by the
transition region 64, the main portion 60 of the cantilevered arm
38 is somewhat thicker than the flange 26, as is the remainder of
the fixation members 30a, 30b, though still not as thick as the
optic periphery 24. Desirably, the fixation members 30a, 30b have a
thickness in the axial dimension of about 0.25 mm.
[0056] As mentioned previously, the intraocular lens 22 of the
present invention is particular well suited for minimally-invasive
implant techniques through extremely small incisions, typically
less than 5 mm, even as low as 3 mm. To enable this desirable
insertion method, the fixation members 30a, 30b flex inward as seen
by the arrow 80 in FIG. 5 on either side of the optic 20 to present
an insertion profile having a dimension A. The dimension A is
desirably less than 5 mm, and preferably about 3 mm. The fixation
members 30a, 30b are flexed inward toward the 3/9 o'clock axis (see
FIG. 2) using forceps, or other tools such as a Bartell-style
injector.
[0057] Because the fixation members 30a, 30b are relatively rigid
in comparison to the optic 20, they are the elements that must be
reduced in profile to less than the size of the incision. The optic
20, on the other hand, is highly pliable and ultrathin and thus may
be left unfolded during the insertion process. When the optic 20
passes through the incision, it naturally deforms and/or folds
through the incision without damage to the adjacent tissue. In
other words, the optic 20 is so thin and flexible that it deforms
through the incision without manipulation, and then springs outward
into its original disk shape in the anterior chamber or capsular
bag. As a result, the method includes flexing both of the fixation
members 30a, 30b toward one another so that they overlap within the
diameter of the optic 20 and define a profile of less than about 5
mm, and passing the intraocular lens 22 in the direction of the 3/9
o'clock axis through an incision of 5 mm or less without otherwise
manipulating the optic into a fold.
[0058] While this invention has been described with respect to
various specific examples and embodiments, it is to be understood
that the invention is not limited thereto and that it can be
variously practiced within the scope of the following claims.
* * * * *