U.S. patent application number 10/271120 was filed with the patent office on 2003-02-20 for iris fixated intraocular lens and method of implantation.
Invention is credited to Laguette, Stephen W., Weinschenk, Joseph I. III.
Application Number | 20030036796 10/271120 |
Document ID | / |
Family ID | 23922852 |
Filed Date | 2003-02-20 |
United States Patent
Application |
20030036796 |
Kind Code |
A1 |
Laguette, Stephen W. ; et
al. |
February 20, 2003 |
Iris fixated intraocular lens and method of implantation
Abstract
Iris fixated intraocular lenses include an optic and at least
one fixation member or haptic. The fixation member is joined to the
optic and has a distal segment including a through-iris portion
adapted to extend through an iris hole, and an anchor portion. The
anchor portion has or is adapted to have an anchor structure
positioned to be disposed proximate to a side of the iris so as to
be effective in fixating the intraocular lens to the iris. The
anchor structure may be formed prior to inserting the intraocular
lens in the eye or may be formed after the intraocular lens is
inserted in the eye. Methods for inserting such intraocular lenses
in the eye are also provided.
Inventors: |
Laguette, Stephen W.; (Santa
Barbara, CA) ; Weinschenk, Joseph I. III; (Laguna
Niguel, CA) |
Correspondence
Address: |
Advanced Medical Optics, Inc.
1700 E. St. Andrew Place
Santa Ana
CA
92705
US
|
Family ID: |
23922852 |
Appl. No.: |
10/271120 |
Filed: |
October 14, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10271120 |
Oct 14, 2002 |
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09484126 |
Jan 12, 2000 |
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6478821 |
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Current U.S.
Class: |
623/6.36 ;
623/6.43; 623/6.59 |
Current CPC
Class: |
A61F 2/1608 20150401;
A61F 2/1602 20130101; A61F 2002/1683 20130101 |
Class at
Publication: |
623/6.36 ;
623/6.43; 623/6.59 |
International
Class: |
A61F 002/16 |
Claims
What is claimed is:
1. An intraocular lens for fixation to an iris of an eye, the iris
having a side and a hole extending from the iris side and through
the iris, the intraocular lens comprising: an optic; and at least
one fixation member joined to the optic comprising a distal segment
including a through-iris portion adapted to extend through the iris
hole and an anchor portion having or adapted to have an anchor
structure positioned to be disposed proximate to the iris side so
as to be effective in fixating the intraocular lens to the
iris.
2. The intraocular lens of claim 1, wherein: the eye includes an
anterior chamber in front of the iris and a posterior chamber
behind the iris; the optic is adapted to be disposed in the
anterior chamber; and the anchor portion is adapted to be disposed
in the posterior chamber or the anterior chamber.
3. The intraocular lens of claim 2, wherein the at least one
fixation member includes a plate element joined to the optic and
adapted to be disposed in the anterior chamber.
4. The intraocular lens of claim 1, wherein the anchor portion has
the anchor structure prior to the intraocular lens being placed in
the eye.
5. The intraocular lens of claim 1, wherein the anchor portion is
adapted to form the anchor structure after the intraocular lens is
placed in the eye.
6. The intraocular lens of claim 5, wherein the anchor portion
comprises a hydrophilic material adapted to form the anchor
structure in the eye.
7. The intraocular lens of claim 6, wherein the hydrophilic
material comprises an acid-treated polymer or a base-treated
polymer.
8. The intraocular lens of claim 6, wherein the hydrophilic
material comprises a hydrogel-forming polymeric material.
9. The intraocular lens of claim 5, wherein the anchor portion
comprises an elastic memory material adapted to form the anchor
structure in the eye.
10. The intraocular lens of claim 1, wherein the anchor structure
has a transverse cross-sectional area that is larger than a
transverse cross-sectional area of the through-iris portion.
11. The intraocular lens of claim 1, which includes at least three
of the fixation members.
12. The intraocular lens of claim 1, wherein the optic has a
thickness in a range of about 200 microns to about 500 microns.
13. The intraocular lens of claim 1, wherein: the hole in the iris
extends between the side and a substantially opposing side of the
iris; and the distal segment includes another anchor portion having
or adapted to have another anchor structure positioned to be
disposed proximate to the substantially opposing iris side.
14. The intraocular lens of claim 13, which has at least one of the
anchor structure and the other anchor structure prior to the
intraocular lens being placed in the eye.
15. The intraocular lens of claim 13, wherein at least one of the
anchor structure and the other anchor structure is adapted to be
formed after the intraocular lens is placed in the eye.
16. The intraocular lens of claim 13, wherein at least one of the
anchor structure and the other anchor structure has a transverse
cross-sectional area that is larger than a transverse
cross-sectional area of the through-iris portion.
17. The intraocular lens of claim 13, wherein: the eye comprises an
anterior chamber in front of the iris, and a posterior chamber
behind the iris; the optic is adapted to be disposed in the
anterior chamber; the anchor structure is adapted to be disposed in
the posterior chamber; and the other anchor structure is adapted to
be disposed in the anterior chamber.
18. The intraocular lens of claim 17 wherein the anchor structure
is adapted to be formed after the intraocular lens is placed in the
eye and the other anchor structure is adapted to be present prior
to the intraocular lens being placed in the eye.
19. The intraocular lens of claim 13, wherein: the anchor portion:
is adapted to enlarge in the eye and form the anchor structure; or
comprises an elastic memory material adapted to form the anchor
structure in the eye; or has a transverse cross-sectional area that
is larger than a transverse cross-sectional area of the
through-iris portion; and the other anchor portion: is adapted to
enlarge in the eye and form the other anchor structure; or
comprises an elastic memory material adapted to form the other
anchor structure in the eye; or has a transverse cross-sectional
area that is larger than a transverse cross-sectional area of the
through-iris portion.
20. The intraocular lens of claim 1 wherein the anchor structure is
adapted to be disposed in a posterior chamber of the eye and has a
generally elliptical transverse cross-sectional area.
21. The intraocular lens of claim 1 wherein the optic is deformable
so that the intraocular lens can be inserted into an eye through a
small incision.
22. An intraocular lens for fixation to an iris of an eye having an
anterior chamber in front of the iris and a posterior chamber in
back of the iris, the iris having a side and a plurality of spaced
apart holes extending from the iris side and through the iris, the
intraocular lens comprising: an optic adapted to be disposed in the
anterior chamber of the eye; and a plurality of spaced apart
fixation members, each of the fixation members including a plate
element joined to the optic and adapted to be disposed in the
anterior chamber of the eye, and a distal segment including a
through-iris portion adapted to extend through one of the iris
holes and an anchor portion having or adapted to have an anchor
structure positioned to be disposed in the posterior chamber
proximity to the iris side so as to be effective in fixating the
intraocular lens to the iris.
23. The intraocular lens of claim 22 including at least 3 of the
fixation members.
24. The intraocular lens of claim 22, wherein each of the anchor
portions has the anchor structure prior to the intraocular lens
being placed in the eye or is adapted to form the anchor structure
after the intraocular lens is placed in the eye.
25. The intraocular lens of claim 22, wherein the optic and the
plate elements are deformable so that the intraocular lens can be
inserted into the eye through a small incision.
26. A method for fixating an intraocular lens to an iris of an eye,
the method comprising the steps of: inserting the intraocular lens
into the eye; directing a distal segment of a fixation member of
the intraocular lens through a through-hole extending through the
iris such that a through-iris portion of the distal segment is
disposed in the hole; and disposing an anchor structure of the
distal segment proximate to a side of the iris, whereby the anchor
structure is effective in fixating the intraocular lens to the
iris.
27. The method of claim 26, wherein the anchor structure is a
preformed anchor structure and the disposing step includes passing
the preformed anchor structure through the through hole of the
iris.
28. The method of claim 26, wherein the disposing step includes
changing the shape of an anchor portion of the distal segment in
the eye to form the anchor structure.
29. The method of claim 28, wherein the anchor portion comprises a
hydrophilic material and the changing step includes causing the
anchor portion to absorb aqueous fluid and form the anchor
structure.
30. The method of claim 28, wherein the anchor portion comprises an
elastic memory material, and the changing step comprises directing
energy to the anchor portion, whereby the anchor portion absorbs
the energy and the anchor structure is formed.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to intraocular lenses (IOLs) and in
particular to IOLs that reduce or even eliminate irritation of the
ciliary band or angle and the sulcus in the eye and reduce the
incidence of pupillary block, and, if a natural crystalline lens is
present, to reduce the risk of cataract formation.
[0002] IOLs are commonly used to modify vision. For example, IOLs
are used to replace the natural lens of the eye when warranted by
medical conditions. A common practice is to implant an IOL in a
region of the eye known as the capsular bag or posterior bag or
capsule. However, in this practice, a potential risk exists that
cells from the eye may grow in front of and/or in back of the
optical portion of the IOL. Such cell growth tends to block the
optical portion of the IOL and impair vision.
[0003] IOLs may be implanted in regions of the eye other than in
the capsular bag. Anterior chamber IOLs (AIOLs) and posterior
chamber IOLs (PIOLs) are known in the prior art. These prior art
IOLs are designed such that a portion of the haptics of the IOLs
are located against the angle or ciliary band of the eye for the
AIOLs or against the sulcus of the eye for the PIOLs.
[0004] A disadvantage of the prior art AIOLs is the risk that the
fixation members or haptics of the AIOLs may irritate the ciliary
band. A disadvantage of the PIOLs is the risk that the optic of the
PIOLs may irritate the natural crystalline lens, if such lens is
present, and possibly result in cataract formation.
[0005] Referring now to Prior Art FIG. 1, a posterior/anterior
chamber intraocular lens (APACL@) 10 combines the advantage of an
optic 12 positioned in the anterior chamber 14 of an eye 16 and
haptics 18 that position the lens resting in the sulcus 20. The
PACL 10 reduces the opportunity of irritation to the angle or
ciliary band 22 and the natural lens 24. Such PACLs are disclosed
in U.S. patent application Ser. No. 09/166,328 filed Oct. 5, 1998,
which is commonly assigned with the present application and is
incorporated herein in its entirety by reference.
[0006] The eye 16 is comprised of a cornea 26 shown to the left and
an iris 28 shown in the middle of the eye. It is to be understood
that the cornea 26 is at the front of the eye 16. The iris 28
divides the eye 16 into the anterior chamber 14 at the front of the
eye and the posterior chamber 30 in the back of the eye. The iris
28 also defines the pupil 32, which is the opening in the middle of
the iris. In front of the iris 28 is the sclera spur 34. The sclera
spur 34 and the iris 28 delimit the ciliary band 22. Behind the
iris 28 is the ciliary process 36, from which extends the ciliary
muscle 38. The ciliary muscle 38 supports the natural crystalline
lens 24 of the eye 16. The iris 28 and the ciliary process 36
define the sulcus 20.
[0007] The haptics 18 of the PACL 10 are two opposing elongated
fixation members that extend from the optic 12. The optic 12
defines an optical axis 50 that extends through the center 52 of
the optic. The haptics 18 have a proximal segment 54 attached to
the optic 12, an intermediate segment 56, and terminates in a
distal segment 58. The optic 12 and the proximal segment 54 are
located in the eye anterior chamber 14. The haptic distal segment
58 rests against the sulcus 20.
[0008] The intermediate segment 56 of the haptic 18 extends through
a hole 60 in the periphery of the iris 28. The intermediate segment
56 is substantially parallel to the optical axis 50. The holes 60
may be formed by an iridectomy, or be naturally occurring openings
in the iris 28. The holes 60 have an additional benefit of
improving fluid flow between the anterior chamber 14 and the
posterior chamber 30. Other details of the PACL 10 are disclosed in
the above-incorporated U.S. Patent Application.
[0009] Recently developed AlOLs for insertion in eyes which contain
the natural crystalline lens (Aphakic@ eyes) include the Nuvita.TM.
MA-20 lens, which has a four-point haptic for fixation in the
angle, and is made of rigid polymethyl methacrylate (PMMA). Another
AIOL used in phakic eyes is known as the Artisan lens and is
disclosed in Worst U.S. Pat. No. 5,192,319, which is incorporated
in its entirety herein by reference. This AIOL is fixated on the
iris by Apinching@ the iris tissue. Made of rigid PMMA, the
Artisan.TM. lens is difficult to implant due to the delicacy of the
iris tissue. Worst U.S. Pat. No. 4,215,440, which is incorporated
in its entirety herein by reference, discloses another iris-fixated
AIOL, which uses one or more fixation members, each having a pair
of pincer arms that pinch an anterior surface of the iris. This
AIOL detachably attaches the IOL to the iris such that the optic is
positioned in the iris opening and has many of the same
disadvantages as does the Artisan lens. Suzuki U.S. Pat. No.
5,628,796, which is incorporated in its entirety herein by
reference, discloses an AIOL with fixation arms or support legs
that are inserted in and through fine bores or apertures made by
incision in a peripheral site of the iris.
[0010] Disadvantages associated with these IOLs for phakic
implantation include a requirement for large incisions in the
cornea for non-foldable IOLs and potential for damage and
inflammation to delicate tissue from rigid haptics. Also involved
are one or more of the complications which include corneal
endothelial cell loss due to mechanical abrasion against the
cornea, inflammation, pupil ovalization, problems with aqueous flow
in the iridio-comeal angle, and implant decentration.
[0011] There continues to be a need for new IOLs.
SUMMARY OF THE INVENTION
[0012] New iris fixated intraocular lenses (IFIOLs) have been
discovered. The present IFIOLs are relatively easy and
straightforward to implant in the eye and effectively fixate to the
iris of the eye. The present IFIOLs are adapted to be firmly
fixated to the iris, for example, so as to prevent accidental
dislodgement. These IFIOLs can be sized and structured so as not to
interfere with the zonules and sulcus angle of the eye, and with
the natural lens of the eye, if such natural lens is present.
[0013] The iris to which the present IFIOL is fixated has a side
and a hole, for example, a iridectomy hole or opening, extending
from the iris side and through the iris. In one broad aspect, the
present IFIOLs comprise an optic and at least one fixation member
or haptic. The fixation member is joined to the optic and includes
a distal segment including a through-iris portion adapted to extend
through the iris hole and an anchor portion. The anchor portion has
or is adapted to have an anchor structure positioned to be disposed
proximate to the iris side so as to be effective in fixating the
IFIOL to the iris.
[0014] In one aspect of the invention, the optic is adapted to be
disposed in the anterior chamber while the anchor portion is
adapted to be disposed in the posterior chamber or the anterior
chamber, preferably in the posterior chamber.
[0015] The anchor portion may have the anchor structure prior to
the intraocular lens being placed in the eye or the anchor portion
may be adapted to form the anchor structure after the intraocular
lens is placed in the eye.
[0016] In one embodiment, the anchor portion adapted to form the
anchor structure after insertion or placement in the eye may be
comprised of hydrophilic material adapted to absorb aqueous fluid
and form the anchor structure in the eye. The hydrophilic material
used may be any suitable such material, for example, a material
suitable for use in the eye. Examples of useful hydrophilic
materials include, but are not limited to, acid-treated polymers,
base-treated polymers, hydrogel-forming polymeric materials and the
like and mixtures and combinations thereof.
[0017] In another embodiment of the invention, the anchor portion
adapted to form the anchor structure after insertion in the eye may
be comprised of an elastic memory material adapted to form the
anchor structure in the eye. Any suitable elastic memory material
may be employed, provided that such material is useful in the eye
and can be treated in the eye to form the anchor structure at
conditions which do not detrimentally affect the eye. Examples of
useful elastic memory materials are well known in the art.
[0018] In one embodiment, the anchor structure has a transverse
cross-sectional area that is larger than a transverse
cross-sectional area of the through-iris portion of the fixation
member. Also, the through-iris portion may, and preferably does,
have a longitudinal axis oriented in a direction other than normal
to an optical axis of the optic.
[0019] The IFIOLs of the invention may have at least three fixation
members, for example, three or four fixation members, but may also
have any number of such members. Further, not all of the fixation
members need be adapted to fixate to the iris.
[0020] In one particularly useful embodiment, fixation member or
members include a plate, or plate-like, element joined to the
optic. Such plate elements have been found to effectively
facilitate fixating the present IFIOLs to the iris. For example,
the plate elements are effective in reducing, or even substantially
eliminating, movement of the optic in the eye which can
disadvantageously cause vision distortion. One important feature of
these plate elements is in facilitating the placement of the IFIOLs
in the eye. Thus, the relatively large and strong plate elements
provide a degree of structural rigidity and are adapted to
facilitate passing the distal segments of the fixation members into
and through the holes in the iris. Such facilitation increases the
ease with which the IOL is installed in the eye and, thereby
advantageously, reduces patient trauma and/or surgeon stress.
[0021] In one aspect of the invention, the distal segment of the
fixation member includes an other or an additional anchor portion
having or adapted to have an other or an additional anchor
structure. In this aspect, the first anchor portion is adapted to
be disposed on one side of the iris, the second anchor portion
preferably is adapted to be disposed on the other side of the iris,
and the through-iris portion of the distal segment extends through
the iris hole and between the two anchor portions. One or both of
the two anchor structures may be formed prior to insertion of the
IFIOL into the eye or may be formed after the IFIOL is placed in
the eye. One of the anchor structures preferably is adapted to be
disposed in the posterior chamber while the other anchor structure
preferably is adapted to be disposed in the anterior chamber. In a
very useful embodiment, the anchor structure is adapted to be
formed after the IFIOL is placed in the eye and the other anchor
structure is adapted to be present prior to the intraocular lens
being placed in the eye. The two anchor structures may have
substantially the same or different configurations.
[0022] In one embodiment, one or both of the anchor portion and the
other anchor portion are adapted to enlarge in the eye and form an
anchor structure, or comprise an elastic memory material adapted to
form an anchor structure in the eye, or have a transverse
cross-sectional area that is larger than a transverse
cross-sectional area of the through-iris portion of the fixation
member.
[0023] In one embodiment, the anchor structure adapted to be
disposed in a posterior chamber of the eye has a generally
elliptical transverse cross-sectional area. This is particularly
useful when the anchor structure is formed prior to the IFIOL being
placed in the eye. Such elliptical cross-sectional area facilitates
placing the preformed anchor structure through the hole in the
iris.
[0024] Methods of fixating an IOL, for example, the present IFIOLs,
to an iris of an eye have been discovered. Such methods comprise
inserting or placing the IOL into the eye, for example, through an
incision in the eye. A distal segment of a fixation member of the
IOL is directed through a through-hole extending through the iris
such that a through-iris portion of the distal segment is disposed
in the hole. The hole in the iris may be formed as part of the
present methods, for example, employing conventional iridectomy
techniques. An anchor structure of the distal segment is disposed
or placed proximate to a side of the iris so that the anchor
structure is adjacent the through-iris portion and the anchor
structure is effective in fixating the intraocular lens to the
iris.
[0025] In one embodiment, the anchor structure is a preformed
anchor structure and the disposing step includes passing the
preformed anchor structure through the through hole in the iris.
Alternately, the present methods may include a step of changing the
shape of an anchor portion of the distal segment in the eye to form
the anchor structure. In this embodiment, the anchor portion may
comprise a hydrophilic material and the changing step includes
causing the anchor portion to absorb aqueous fluid, for example,
from the eye, and form the anchor structure. The anchor portion may
comprise an elastic memory material, and the changing step includes
directing energy to the anchor portion, whereby the anchor portion
absorbs the energy and the anchor structure is formed.
[0026] Each and every feature described herein, and each and every
combination of two or more of such features is included with the
scope of the present invention provided that the features included
in such a combination are not mutually inconsistent.
[0027] These and other aspects of the present invention are
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
[0028] Prior Art FIG. 1 is a cross-sectional view of an eye with a
posterior/anterior intraocular lens implanted therein.
[0029] FIG. 2 is a perspective view of an iris fixated intraocular
lens before implantation in an eye according to an embodiment of
the invention.
[0030] FIG. 3 is a cross sectional view of the iris fixated
intraocular lens of FIG. 2 implanted in an eye with formed anchor
structures of hydrogel at the ends of the fixation members.
[0031] FIG. 4 is a detail view of the formed anchor structure of
the iris fixated intraocular lens fixation member of FIG. 3.
[0032] FIGS. 5 and 6 are detail views of formed anchor structures
of the iris fixated intraocular lens made of elastic memory
material.
[0033] FIG. 7 is a perspective view of an iris fixated intraocular
lens before implantation in an eye according to an embodiment of
the invention.
[0034] FIG. 8 is a cross sectional view of the iris fixated
intraocular lens of FIG. 7 implanted in an eye with formed anchor
structures at the ends and intermediate portions of the fixation
members.
[0035] FIG. 9 is a perspective view of an iris fixated intraocular
lens before implantation in an eye according to an embodiment of
the invention.
[0036] FIG. 10 is a cross sectional view of the iris fixated
intraocular lens of FIG. 9 implanted in an eye with formed anchor
structures at the ends and preformed anchor structures at the
intermediate portions of the fixation members.
[0037] FIG. 11 is a perspective view of an iris fixated intraocular
lens before implantation in an eye according to an embodiment of
the invention.
[0038] FIG. 12 is a side view of the iris fixated intraocular lens
of FIG. 11 showing the vaulting of the optic relative to the
fixation members.
[0039] FIG. 13 is a cross sectional view of the iris fixated
intraocular lens of FIG. 11 implanted in an eye with preformed
anchor structures at the ends at the intermediate portions of the
fixation members.
[0040] FIGS. 14 and 15 are detail views of anchor portions of
fixation members of the iris fixated intraocular lens of FIG. 11
according to embodiments of the invention.
[0041] FIG. 16 is a front view of an alternate iris fixated
intraocular lens before implantation in an eye according to an
embodiment of the present invention.
[0042] FIG. 17 is a side view of the iris fixated intraocular lens
of FIG. 16.
DETAILED DESCRIPTION OF THE DRAWINGS
[0043] Referring now to drawings, FIG. 2 shows an iris fixated
intraocular lens (AIFIOL@) 110 according to an embodiment of the
invention in which the fixation members 118 come into contact with
neither the sulcus nor the angle or ciliary band of the eye. The
IFIOL 110 is comprised of an optic 112 and three fixation members
or haptics 118. The optic 112 has an optical axis 150 extending
through the center 152 of the optic and is generally normal to the
optic. Each fixation member 118 has an elongated proximal segment
154 attached to the optic 112 near the periphery 113 of the optic.
Each fixation member also has a distal segment 156 joined to the
proximal segment 154, comprising a through-iris portion 157 and
preferably terminating in a shape-changeable end 158.
[0044] The optic 112 in the shown embodiment is circular in plan
and bi-convex (see FIG. 3). Other embodiments of the invention may
have other configurations and shapes, such as convex-concave,
bi-concave, planar-convex, planar concave, toric, and multifocal,
for example, as disclosed in Portney U.S. Pat. No. 5,225,858, which
is incorporated in its entirety herein by reference.
[0045] The optic 112 may be constructed of any commonly employed
material or materials used for rigid optics, such as
polymethylmethacrylate (PPMA), or commonly used for resiliently
deformable or foldable optics, such as silicone polymeric
materials, acrylic polymeric materials, hydrogel-forming polymeric
materials, such as polyhydroxyethylmethacrylat- e,
polyphosphazenes, polyurethanes, and mixtures thereof and the like.
The particular material should form an optically clear optic 112
and exhibit biocompatability in the environment of the eye 16.
Selection parameters for suitable intraocular lens materials are
well known to those of skill in the art. See, for example, David J.
Apple, et al., Intraocular Lenses. Evolution, Design,
Complications, and Pathology, (1989) William & Wilkins.
Foldable/deformable materials are particularly advantageous since
optics made from such deformable materials may be rolled, folded or
otherwise deformed and inserted into the eye through a small
incision. It is preferred that the lens material has a refractive
index allowing a relatively thin, and preferably flexible optic
section, for example, having a thickness in the range of about 150
microns to about 1000 microns, and preferably about 150 microns or
about 200 microns to about 500 microns. Further, the optic 112 may
have a diameter of about 4.5 mm or less to about 6.6 mm or more,
preferably about 5.0 mm to about 6.0 mm or about 6.5 mm, to avoid
edge glare and be properly sized for placement in an adult human
eye. In comparison, the distal segments 156 lie on a circle having
a diameter of about 8 mm or less to about 11 mm or more, for
example, about 9.5 mm, in an embodiment of the invention.
[0046] The fixation members 118 preferably are flexible yet
sufficiently strong and resilient to hold the optic 112 in place
yet permit the fixation members to flex in response to iris 28
movement. The fixation member may have a substantially circular
transverse area diameter in a range of about 0.1 mm or less and
about 0.2 mm or more, for example about 0.15 mm. Other embodiments
of the invention may have fixation members with transverse areas of
other shapes, such as oval, rectangular and the like. The fixation
members 118 preferably are designed to flex so as to restrict or
substantially eliminate movement of the optic 112 in the direction
of the optical axis 150.
[0047] Optics and haptics in accordance with the present invention
having the above-noted thicknesses and diameters can be produced
using manufacturing methodologies which are conventional and well
known in the IOL art.
[0048] The fixation members 118 may be formed integrally with the
optic 102 or may be separately attached to the optic. The fixation
members 118 may comprise any of a variety of materials which
exhibit sufficient supporting strength and resilience, and which
are substantially biologically inert in the intended in vivo or
in-the-eye environment. Suitable materials for this purpose
include, for example, polymeric materials such as polypropylene,
PMMA, polycarbonates, polyamides, polyimides, polyacrylates,
2-hydroxymethylmethacrylate, poly(vinylidene fluoride),
polytetrafluoreothylene and the like; and metals such as stainless
steel, platinum, titanium, tantalum, shape-memory alloys, e.g.,
nitonal, and the like.
[0049] More preferably, the fixation members 118 comprise a
polymeric material, in particular selected from polypropylene, PMMA
and polyimides, and especially polypropylene. The fixation members
118 can be produced using conventional and well known forming
techniques. For example, the preferred polymeric fixation members
can be formed in accordance with known thermoplastic polymer
forming techniques, such as by injection molding or by extrusion.
Further, selection parameters for suitable intraocular lens
materials are well known to those skilled in the art.
[0050] Each fixation member proximal segment 154 defines an arc
that extends generally normal to the optical axis 150. Each
fixation member 118 has a discontinuity 160 where the proximal
segment 154 joins the distal segment 156. In the shown embodiment
of the invention, the proximal and distal segments 154 and 156 form
a right angle 162, resulting in the iris-through portion 157 being
parallel to the optical axis 150. Other embodiments of the
invention may have the through-iris portion 157 oriented in a
direction other than normal to the optical axis 150. Still other
embodiments of the invention may have proximal segments 154 of any
suitable configuration.
[0051] In the shown embodiment, the three fixation members 118 are
symmetrical. Other embodiments of the invention may have
non-symmetrical fixation members. In the shown embodiment of the
invention, the fixation members 118 extend generally tangentially
away from the optic periphery 113. Other embodiments of the
invention may have fixation members 118 attached to the optic 112
which extend in a non-tangential fashion. Still other embodiments
of the invention may have any number of fixation members of similar
or different design. The shown embodiment of the invention has
three fixation members 118 to increase stability of the IFIOL in
the eye. Embodiments of the invention may have optics and fixation
members that are essential unitary or may be assembled.
[0052] In an embodiment of the invention, the fixation members 118
are made of two or more materials. In a further embodiment of the
invention, the shape-changeable end 158 may be comprised of a
different material than the remainder of the fixation member
118.
[0053] Referring now to FIGS. 3 and 4 as well, the shape-changeable
end 158 of the fixation member 118 is adapted to form an anchor
structure 158a once the IFIOL 110 is implanted in the eye 16. The
cross-sectional view shown in FIG. 3 is such that two of the three
fixation members 118 are represented for clarity, although a
straight cross-section would only show one of the three fixation
members.
[0054] Prior to implantation, an iridectomy is performed to form
the holes 60 that extend through the iris 28. The iridectomy is
surgically formed using methods and instruments well known in the
art. See, for example, the Apple et al, publication noted
previously. The hole 60 is formed through the iris 28 so that the
hole 60 receives the fixation member 118 and the fixation member
fixably engages the IFIOL 110 to the iris. Fixed to the iris 28,
the optic 112 of the IFIOL 110 is aligned with the pupil 32. In
some embodiments of the invention, the fixation member 118 deforms
the hole 60 while being inserted and in other embodiments the
fixation member does not deform the hole, as described below. The
iridectomy facilitates fluid flow between the anterior chamber 14
and the posterior chamber 30. In a preferred embodiment of the
invention, the holes 60 are near the outer periphery of the iris 28
because the radial positions of the holes do not substantially
change during dilation and contraction of the iris compared to
portions of the iris nearer the pupil. Other embodiments of the
invention may have the holes 60 located other than the outer
periphery of the iris 28. The holes 60 extend generally parallel to
the optical axis 150. Other embodiments of the invention may have
the holes 60 extending other than parallel to the optical axis 150.
The holes 60 may be of any shape, including circular, oval, or
slit.
[0055] In the shown embodiment of the invention, the IFIOL 110 is
implanted such that the optic 112 and the proximal segments 154 of
the fixation members 118 are disposed in the anterior chamber 14.
With the optic 112 in the anterior chamber 14, there is a reduced
opportunity for the IFIOL 110 to contact the natural lens 24 and
initiate pupillary block and cataract formation. However, it should
be understood that IFIOL 110 can be implanted in and function
satisfactorily in an eye in which the natural lens has been
extracted, e.g., using conventional techniques, or in an eye in
which the natural lens has been extracted and replaced by an
intraocular lens, e.g., of conventional design, located in the
posterior chamber. Additionally, embodiments of the invention
include IFIOLs adapted for the optic to be in the posterior chamber
30.
[0056] Further, the IFIOL 110 is implanted such that the fixation
member distal segments 156 extend through the iris hole 60. More
specifically, the through-iris portion 157 is disposed in the iris
hole 60 and the formed anchor structure 158a is disposed in the
posterior chamber 30 and proximate to an iris side 28a that defines
the posterior chamber.
[0057] The formed anchor structure 158a has a diameter 170 that is
greater than a diameter 172 of the hole 60. When the distal segment
156 was originally inserted through the hole 60, the
shape-changeable end 158 (see FIG. 2) is able to pass through the
hole without substantially deforming the walls 61 of the hole and
potentially enlarging or tearing the hole.
[0058] In the shown embodiment of the invention, the
shape-changeable end 158 comprises a hydrophilic material that
absorbs aqueous fluid in the eye 16 and swells to form the bulbous
anchor structure 158a after passing through the hole 60. The formed
anchor structure 158a cannot pass back through the hole 60 due to
its diameter 170 relative to the diameter 172 of the hole without
deforming the iris hole walls 61. Further, as the anchor structure
diameter 170 is greater than the hole diameter 172, the
cross-sectional area of the anchor structure 158a is greater than
the cross-sectional area of the hole 60. The cross-sectional area
of the hole 60 is taken normal to the axis 173 of the hole. The
cross-sectional area of the anchor structure 158a is taken normal
to the centerline 175 of the fixation member at the anchor
structure.
[0059] Embodiments of the invention include any suitable
arrangement of any hydrophilic material that results in the formed
anchor structure 158a that cannot pass through the hole 60 without
deforming the walls 61 of the hole. The shown embodiment of the
invention has a bulbous shape, but embodiments of the invention are
not limited to hydrophilic material that forms a bulbous shape upon
absorption of fluid. For example, the formed anchor structure of
other embodiments may be any rotational shape, partial rotational
shape, or non-rotational shape that has a width greater than a
width of the hole 60, whereby the anchor structure cannot be
directed through the hole without distorting the hole.
[0060] It is understood that Awidth@ is a length of the span of the
opening of the hole 60 or the anchor portion in a direction normal
to the axis of the hole. In the case of a circular anchor structure
and a circular opening of the hole 60, the width is a diameter. In
the cases of non-circular holes and anchor structures, the width is
any span. Additionally, when the IFIOL 110 is installed in the eye
16, the widths of respective anchor structures and holes are
oriented such that the anchor structure cannot be directed through
the hole without distorting the hole.
[0061] Examples of hydrophilic materials of the
shape-changeable-end 158a of embodiments of the invention include
acid or base treated polymeric materials. The shape-changeable end
158a may comprise a hydrogel-forming polymeric material, either
entirely or a portion, such as a coating on a non-hydrogel-forming
component of the shape-changeable end. Examples of suitable
hydrogel-forming polymeric materials include poly(2-hydroxyethyl
methacrylate) and a copolymer of ethyl methacrylate and
N,N-dimethylacrylamide.
[0062] The shape-changeable end 158a may be the result of treating
the end of the fixation member 118 with acid or base, which reacts
with the fixation member material, such as PMMA or other suitable
material effective when treated with an acid and/or base to provide
a useful hydrophilic material, to form a hydrophilic outer layer.
In further embodiments of the invention, the hydrophilic material
is coated with a dissolvable or otherwise removable or breachable
biocompatible sealer to temporarily inhibit the material absorbing
the fluid, thereby providing a period of time before the material
swells to form the anchor structure.
[0063] Referring now to FIG. 5 as well, in another embodiment of
the invention, the shape-changeable end 158 of the fixation member
118 is comprised of an elastic memory material that changes from a
linear state to a curled state to form the anchor structure 158b.
Attention is drawn to the curled formed anchor 158b structure
having an end 159b that is not in contact with the iris side 28a,
which reduces irritation to the iris 28. The formed anchor
structure 158b is also curled in a direction parallel to the
through-iris portion 157.
[0064] Referring now to FIG. 6, an anchor structure 158c is formed
of elastic memory material that forms a curl that is normal to the
direction of the through-iris portion (not shown). Other
embodiments of the invention may include shape-changeable ends of
elastic memory material that form any suitable formed anchor
structure i.e., an anchor structure that cannot be directed through
the iris hole 60 without deforming the iris hole walls 61 or an
anchor structure having a width greater than a width of the iris
hole. In a preferred embodiment of the invention, the formed anchor
structures 158b and 158c are the result of pinpoint heating of the
shape-changeable end 158 by use of an appropriate energy source,
such as a laser. The shape-changeable end 158 absorbs the energy
and forms the anchor structure.
[0065] In an embodiment of the invention, the elastic memory
material is a polymeric material having a glass transition
temperature (Tg) of at least about 40.quadrature.C. to about
45.quadrature.C., preferably in the range of about 40.quadrature.C.
to about 80.quadrature.C., and more preferably in the range of
about 45.quadrature.C. to about 60.quadrature.C. The polymeric
material should be such that the Tg is sufficiently high to avoid
any changes in the material caused by the physiological environment
of the eye. On the other hand, the Tg of the polymeric material
should not be excessively high, since heating the material to
excessively high temperatures may result in damage or injury to the
eye. Suitable polymeric materials are disclosed in the Weinschenk,
III et al U.S. Pat. No. 5,567,365, which is incorporated herein in
its entirety by reference.
[0066] The elastic memory polymeric material, as well as the
material from which the optic is derived, used should be compatible
with the eye 16 so implantation of the IFIOL 110 does not cause any
significant harm or damage to the eye. Further, the optic 112 and
the fixation members 118 may also comprise the polymeric
material.
[0067] Typical examples of useful elastic memory polymeric
materials include homopolymers of and copolymers derived from
methyl methacrylate, n-hexyl acrylate, ethyl methacrylate, ethyl
acrylate, 3,3-dimethylbutyl methacrylate, isobutyl methacrylate,
cyclohexyl methacrylate, sec-butyl methacrylate, benzyl
methacrylate, 4-tert-butylphenyl acrylate, 4-ethoxycarbonyl phenyl
acrylate, 2-methoxycarbonyl phenyl acrylate, 3-methoxycarbonyl
phenyl acrylate, 4-methoxycarbonyl phenyl acrylate, phenyl
acrylate, and the like and mixtures thereof. Elastic memory
polymeric materials other than acrylic-based materials, such as
certain acrylamides, polyolefins, polycarbonates and the like may
be used in embodiments of the invention. Copolymers are
particularly useful as they may be custom formulated to obtain
specific Tg and other properties desired.
[0068] FIGS. 7 and 8 show alternative IFIOL 210 of the present
invention. Alternative IFIOL 210 is structurally and functionally
similar to IFIOL 110 except as expressly described herein.
Components of alternative IFIOL 210 which correspond to components
of IFIOL 110 are identified by the same reference number increased
by 100.
[0069] Referring now to FIG. 7, IFIOL 210 is comprised of an optic
212 and three fixation members or fixation members 218. The optic
212 has an optical axis 250 extending through the center 252 of the
optic and is generally normal to the optic. Each fixation member
218 has a proximal segment 254 attached to the optic 212 near the
periphery 213 of the optic. Each fixation member also has a distal
segment 256 joined to the proximal segment 254, comprising a
through-iris portion 257, terminating in a shape-changeable end
258, and having a shape-changeable portion 259 between the
through-iris portion and the proximal segment.
[0070] The IFIOL 210 is similar to the IFIOL 110 described above
but for the shape-changeable portion 259. The shape-changeable
portion 259 is adapted to form an additional anchor structure 259a
once the IFIOL 210 is implanted in the eye 16 as shown in FIG.
8.
[0071] The formed additional anchor structure 259a is adapted to be
disposed in the proximity of the iris side 28b, which defines the
anterior chamber 14 and opposes iris side 28a. The anchor structure
258a and the additional anchor structure 259a straddle the iris 28
to hold the through-iris portion 257 in the iris hole 60. Other
embodiments of the invention may include any shape-changeable end
258 and shape-changeable portion 259 of elastic memory material or
hydrogel-forming polymeric material that forms any suitable formed
anchor structure i.e., an anchor structure that cannot be directed
through the iris hole 60 without deforming the iris hole walls 61
or an anchor structure having a width greater than a width of the
iris hole.
[0072] In embodiments of the invention, the shape-changeable end
258 and the shape-changeable portion 259 may comprise any of the
materials discussed above in connection with the shape-changeable
end 158 of IFIOL 110. It also follows that the anchor structure
258a and the additional anchor structure 259a may be formed in the
same manner as discussed above in connection with the
shape-changeable end 158. In the embodiment of the invention in
which the shape-changeable portion 259 is comprised of an elastic
memory material, the formed additional anchor structure 259a is
suitable as an intermediately positioned component of the fixation
member 218, as opposed to the terminally positioned anchor
structure 258a.
[0073] FIGS. 9 and 10 show additional IFIOL 310 of the present
invention. Additional IFIOL 310 is structurally and functionally
similar to IFIOL 110 and IFIOL 210 except as expressly described
herein. Components of additional IFIOL 310 which correspond to
components of IFIOL 110 and IFIOL 210 are identified by the same
reference number increased by 200 and 100, respectively.
[0074] Referring now to FIG. 9, IFIOL 310 is comprised of an optic
312 and three fixation members 318. The optic 312 has an optical
axis 350 extending through the center 352 of the optic and is
generally normal to the optic. Each fixation member 318 has a
proximal segment 354 attached to the optic 312 near the periphery
313 of the optic. Each fixation member also has a distal segment
356 joined to the proximal segment 354, comprising a through-iris
portion 357, terminating in a shape-changeable end 358, and having
a preformed anchor structure 359 between the through-iris portion
and the proximal segment.
[0075] Referring now to FIG. 10, the IFIOL 310 is similar to the
IFIOL 210 described above but for the preformed anchor structure
359 replacing the shape-changeable portion 259. The preformed
anchor structure 359 does not pass through the hole 60 in the iris
28 and, therefore, has a width greater than a width of the iris
hole or otherwise cannot pass through the iris hole without
deforming the iris hole wall 61. The resulting implanted IFIOL 310
is similar to the implanted IFIOL 210.
[0076] FIGS. 11-15 show further IFIOL 410 of the present invention.
Further IFIOL 410 is structurally and functionally similar to
IFIOLs 110, 210 and 310 except as expressly described herein.
Components of further IFIOL 410 which correspond to components of
IFIOLs 110,210, and 310 are identified by the same reference number
increased by 300, 200, and 100, respectively.
[0077] Referring now to FIG. 11, in an embodiment of the invention,
IFIOL 410 is comprised of an optic 412 and three fixation members
418. The optic 412 has an optical axis 450 extending through the
center 452 of the optic and is generally normal to the optic. Each
fixation member 418 has a proximal segment 454 attached to the
optic 412 near the periphery 413 of the optic. Each fixation member
418 also has a distal segment 456 joined to the proximal segment
454, comprising a through-iris portion 457, terminating in a
preformed anchor structure 358, and having another preformed anchor
structure 459 between the through-iris portion and the proximal
segment.
[0078] Referring now to FIGS. 12 and 13, the IFIOL 410 is shown
with an optical plane 480 that is normal to the optical axis 450.
The fixation members 418 extend posteriorly from the optical plane
480, such that the lens 412 is vaulted. The posteriorly positioning
of the fixation members 418 result in the fixation members and the
optic 412 being supported in a spaced apart position to the iris
28. This provides the advantage of mitigating inflammation of the
iris 28 by reducing or eliminating abrasion of the fixation members
418 against the iris surface 28b.
[0079] Referring now to FIGS. 14 and 15, embodiments of the
invention have a distal segment 456 with a circular preformed
anchor structure 458a and an ellipsoidal preformed anchor structure
458b. The ellipsoidal preformed anchor structure 458b is relatively
easy to pass through the iris hole and, once through the hole,
remains posterior to the iris. In one embodiment, the through iris
portion 457b, or at least that part of the through iris portion
which is directly adjacent to ellipsoidal preformed anchor
structure 458b, may be made of an elastic memory material, as
described elsewhere herein. The through iris portion 457b is
produced and structured so that the ellipsoidal anchor structure
458b can be passed through a hole in the iris and, afterward,
because of the elastic memory characteristic of the through iris
portion, is effectively twisted to rotate the anchor structure
458b, for example, through an angle of about 90.degree., to make it
more difficult for the anchor structure to pass through the iris
hole. Thus, the anchor structure 458b is more securely positioned
posterior of the iris and the IOL is more securely fixated to the
iris. This is but one example of embodiments of the present
invention in which combinations of preformed anchor structures and
elastic memory materials can advantageously be used together. Other
embodiments of the invention may have preformed anchor structures
458 and 459 of any suitable shape, including shapes that minimize
contact with the iris 28 and shapes that permit fluid exchange
between the two chambers through the iris through-hole (see FIG.
13).
[0080] FIGS. 16 and 17 show alternate IFIOL 510 in accordance with
the present invention. Alternate IFIOL 510 is structurally and
functionally similar to the IFIOLs 110, 210, 310 and 410 except as
expressly described herein. Components of alternate IFIOL 510 which
correspond to components of IFIOLs 110, 210, 310 and 410 are
identified by the same reference number increased by 400, 300, 200
and 100, respectively.
[0081] The primary difference between IFIOL 510 and the earlier
illustrated IFIOLs relates to the structure of the fixation members
518.
[0082] Thus, referring now to FIGS. 16 and 17, alternate IFIOL 510
is comprised of an optic 512 and three fixation members 518
equidistantly spaced apart around the circular periphery 513 of the
optic. The optic 512 has an optical axis 550 extending through the
center 552 of the optic and is generally normal to the plane of the
optic.
[0083] Each fixation member has a plate or tab element 80 attached
to the optic 512 near the periphery 513 of the optic. The plate
elements 80 are adapted to be placed or disposed in the anterior
chamber of the eye when the IFIOL 510 is fixated to the iris of the
eye. In addition, each fixation member 518 has a distal segment 556
joined to plate element 80 near the distal end 824 of the plate
element. Each distal segment 556 includes a through-iris portion
557, terminating in a preformed anchor structure 559. The plate
elements 80 are shaped so that the distal end 82 is slightly
posterior of the regions of the plate elements 80 directly attached
to the optic 512. This shaping of the plate elements 80 allows the
distal end 82 to act as or be considered another preformed anchor
structure which facilitates maintaining the through-iris portion
557 of each of the fixation members 518 in the iris hole. It is to
be understood that the preformed anchor structures 559 can be
replaced by an anchor structure which is formed only after the
IFIOL 510 is in the eye, for example, as described elsewhere
herein. In addition, the number of fixation members 518 is not
critical to the present invention. However, it is preferred that at
least three, and more preferably three or four, fixation members
518 be provided.
[0084] In contrast to the elongated proximal segments of the
fixation members of the earlier illustrated IFIOLs, the plate
elements 80 are relatively stronger and provide enhanced stability.
However, the plate elements 80, like the optic 512, preferably are
made of a deformable material so that the optic and plate elements
can be rolled, folded or otherwise deformed for insertion into an
eye through a small incision.
[0085] The relatively strong plate elements 80 provide substantial
benefits. For example, such plate elements 80 facilitate, that is
make easier, the placement of IFIOL 510 into the eye. Such
placement in the eye requires less time and/or surgical technique
and/or is less traumatic to the patient and/or is less stressful to
the surgeon, relative to a substantially identical IFIOL in which
the plate elements 80 are replaced by thin filament-like members.
Additionally, after IFIOL 510 is in the eye, the plate elements 80
are effective in stabilizing the optic 512 against unwanted
movement, for example, which can cause distortion in the patient's
vision.
[0086] The plate elements 80 can be made of any suitable material,
many examples of which have been disclosed previously herein. The
plate elements 80 can be made separately from the optic 512 and
then bonded or secured to the optic, or the plate elements and the
optic can be made together as a single piece.
[0087] In a preferred embodiment of the invention, the iridectomy
results in through-iris holes that match the distal segments of the
IFIOL to be implanted in the eye. Further, the IFIOL preferably is
designed to prevent dislodgement of the fixation members from the
iris, and not to interfere with the natural crystalline lens,
zonules, or any other part of the eye. If desired or necessary, the
present IFIOL may be removed from the eye and replaced with another
IFIOL, a PACL, an AIOL, a PIOL, or another eye implant device.
[0088] In embodiments of the invention, at least the terminal ends
of the fixation members may be made of non-transparent material,
such as PMMA with a dye, to facilitate observing the fixation
member placement through the iris hole 60 under proper
illumination. In a preferred embodiment of the invention, the
remainder of the fixation members are made from visually
transparent material to minimize cosmetic issues.
[0089] Enlargement of one or more of the iris holes 60, for
example, after the IFIOL is implanted, may be performed to increase
fluid flow between the anterior and posterior chambers 14 and 30 of
the eye 16. In other embodiments of the invention, the formed or
preformed anchor structures are adapted to permit fluid flow
through the iris holes 60.
[0090] Embodiments of the invention include IFIOLs that are
implanted to address different refraction deficiencies, such as
hyperopia, astigmatism, myopia, and presbyopia.
[0091] In preferred embodiments of the invention, the fixation
members and anchor structures, both preformed and formed in the
eye, are adapted to avoid damaging the iris tissue during
insertion, fixation, and removal of the IFIOL from the eye.
[0092] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. For example, while FIG. 3 shows the IFIOL 110 implanted in
the eye 16 with a natural lens 34, other embodiments of the
invention may have an IFIOL implanted in an eye without a natural
lens, or with a replacement lens. Another example is a fixation
member having a distal end segment comprising both hydrogel
material and elastic memory material. Further, aspects of the
invention may have combinations of the above described embodiments
although these combinations may not be explicitly described.
[0093] 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.
* * * * *