U.S. patent application number 13/366165 was filed with the patent office on 2012-10-04 for intraocular accommodating lens and methods of use.
Invention is credited to Yair Alster, Eugene de Juan, JR., Cary Reich.
Application Number | 20120253459 13/366165 |
Document ID | / |
Family ID | 45768299 |
Filed Date | 2012-10-04 |
United States Patent
Application |
20120253459 |
Kind Code |
A1 |
Reich; Cary ; et
al. |
October 4, 2012 |
INTRAOCULAR ACCOMMODATING LENS AND METHODS OF USE
Abstract
Described herein are intraocular lenses and methods of
implantation. In one aspect, the lens includes a shape changing
optical element; a force translation element having a first end
region coupled to the optical element and a second end region
extending towards a ciliary structure, and an attachment portion
coupled to the second end region of the force translation element
and configured to contact the ciliary structure. The force
translation element is configured to functionally transmit
movements of the ciliary structure into a force exerted upon the
optical element to effect an accommodating and a disaccommodating
change of the optical element.
Inventors: |
Reich; Cary; (Menlo Park,
CA) ; de Juan, JR.; Eugene; (Menlo Park, CA) ;
Alster; Yair; (Menlo Park, CA) |
Family ID: |
45768299 |
Appl. No.: |
13/366165 |
Filed: |
February 3, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61439767 |
Feb 4, 2011 |
|
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|
Current U.S.
Class: |
623/6.46 |
Current CPC
Class: |
A61F 2/1602 20130101;
A61F 2/1648 20130101; A61F 2/1635 20130101; A61F 2250/0018
20130101; F04C 2270/041 20130101; A61F 2002/1682 20150401; A61F
2/1624 20130101 |
Class at
Publication: |
623/6.46 |
International
Class: |
A61F 2/16 20060101
A61F002/16 |
Claims
1. An intraocular lens, comprising: a shape changing optical
element; a force translation element having a first end region
coupled to the optical element and a second end region extending
towards a ciliary structure, wherein the force translation element
is configured to functionally transmit movements of the ciliary
structure into a force exerted upon the optical element to effect
an accommodating and a disaccommodating change of the optical
element; and an attachment portion coupled to the second end region
of the force translation element and configured to contact the
ciliary structure.
2. The lens of claim 1, wherein the force translation element can
be customized for fit during implantation.
3. The lens of claim 2, wherein the mechanism for customizing the
fit is selected from the group consisting of sliding, twisting,
turning, cutting, rolling, expanding, bending, and applying energy
to the force translation element.
4. The lens of claim 1, wherein the force translation element is
coated with an expandable material.
5. The lens of claim 1, wherein at least one of the optical
element, the force translation element, and the attachment portion
is coated with an agent having biological activity.
6. The lens of claim 5, wherein the agent is selected from the
group consisting of heparin, a steroid and rapamicin.
7. The lens of claim 1, wherein the first end region of the force
translation element is coupled to an equator of the optical
element.
8. The lens of claim 1, further comprising a plurality of force
translation elements coupled near an equator of the optical
element.
9. The lens of claim 1, wherein the attachment portion is
configured to contact the ciliary structure.
10. The lens of claim 1, wherein the attachment portion is
configured to abut and not penetrate the ciliary structure.
11. The lens of claim 1, wherein the ciliary structure is selected
from the group consisting of the ciliary muscle, the ciliary body,
a ciliary process, and a zonule.
12. The lens of claim 1, wherein the attachment portion is formed
of an elastic material.
13. The lens of claim 1, wherein the attachment portion comprises
one or more rods.
14. The lens of claim 13, wherein the one or more rods are
curved.
15. The lens of claim 1, wherein the attachment portion comprises a
three dimensional element that fills a space adjacent the ciliary
structure.
16. The lens of claim 1, wherein the attachment portion comprises a
fillable element.
17. The lens of claim 1, wherein the attachment portion comprises a
glue, hydrogel or fixation material.
18. The lens of claim 1, wherein the attachment portion elicits a
healing response in the ciliary structure to induce soft tissue
integration of the attachment portion.
19. The lens of claim 1, wherein the optical element has a power in
the range of about .+-.3 diopters to about .+-.5 diopters.
20. The lens of claim 1, wherein the accommodating change of the
optical element comprises a change from an ovoid shape to a more
spherical shape.
21. The lens of claim 1, wherein the accommodating change of the
optical element comprises a change in spatial configuration along
the optical axis in an anterior direction.
22. The lens of claim 1, wherein the force translation element is
formed of a material generally harder than a material of the
optical element.
23. The lens of claim 1, further comprising a second lens
positioned within the capsular bag of the eye.
24. The lens of claim 23, wherein the optical element is positioned
anterior to the second lens.
25. The lens of claim 24, wherein the optical element is positioned
within the capsular bag of the eye.
26. The lens of claim 24, wherein the optical element is positioned
posterior to the iris.
27. The lens of claim 24, wherein the optical element is positioned
anterior to the iris.
28. The lens of claim 23, wherein the second lens comprises an
implanted intraocular lens.
29. The lens of claim 1, further comprising a haptic coupled to and
extending outward from the optical element.
30. The lens of claim 29, wherein the haptic is positioned within a
sulcus.
31. The lens of claim 30, wherein the force translation element is
coupled to the haptic.
32. The lens of claim 1, wherein the force translation element is
coupled to the ciliary body and configured to push on the optical
element.
33. The lens of claim 1, wherein the force translation element is
coupled to the ciliary body and configured to pull on the optical
element.
34. The lens of claim 1, wherein the accommodating and
disaccommodating change comprises a shape change effected over the
entire surface of the optical element.
35. The lens of claim 1, wherein the accommodating and
disaccommodating change comprises a shape change effected over a
portion of the surface of the optical element.
36. The lens of claim 35, wherein the portion preferentially bulges
upon an accommodating change.
37. The lens of claim 35, wherein the shape change effected over a
portion is due to a difference in modulus of the portion of the
optical element compared to the modulus of another portion of the
optical element.
38. The lens of claim 37, wherein a center region of the optical
element comprises a lower modulus material than an outer region of
the optical element.
39. The lens of claim 38, wherein the lower modulus material gives
way causing a bulge and a change in dioptric effect.
Description
REFERENCE TO PRIORITY DOCUMENT
[0001] This application claims priority of co-pending U.S.
Provisional Patent Application Ser. No. 61/439,767, entitled
"Intraocular Accommodating Lens and Methods of Use," filed Feb. 4,
2011. Priority of the aforementioned filing date is hereby claimed
and the disclosure of the Provisional Patent Application is hereby
incorporated by reference in its entirety.
BACKGROUND
[0002] The present disclosure relates generally to the field of
ophthalmics, more particularly to ophthalmic devices, including
intraocular lenses (IDLs) such as accommodating intraocular
lenses.
[0003] A healthy young human eye can focus an object in far or near
distance, as required. The capability of the eye to change back and
forth from near vision to far vision is called accommodation.
Accommodation occurs when the ciliary muscle contracts to thereby
release the resting zonular tension on the equatorial region of the
capsular bag. The release of zonular tension allows the inherent
elasticity of the lens capsule to alter to a more globular or
spherical shape, with increased surface curvatures of both the
anterior and posterior lenticular surfaces.
[0004] The human lens can be afflicted with one or more disorders
that degrade its functioning in the vision system. A common lens
disorder is a cataract which is the opacification of the normally
clear, natural crystalline lens matrix. The opacification can
result from the aging process but can also be caused by heredity or
diabetes. In a cataract procedure, the patient's opaque crystalline
lens is replaced with a clear lens implant or IOL.
[0005] In conventional extracapsular cataract surgery, the
crystalline lens matrix is removed leaving intact the thin walls of
the anterior and posterior capsules together with zonular ligament
connections to the ciliary body and ciliary muscles. The
crystalline lens core is removed by phacoemulsification through a
curvilinear capsularhexis i.e., the removal of an anterior portion
of the capsular sac.
[0006] After a healing period of a few days to weeks, the capsular
sac effectively shrink-wraps around the IOL due to the
capsularhexis, the collapse of the walls of the sac and subsequent
fibrosis. Cataract surgery as practiced today causes the
irretrievable loss of most of the eye's natural structures that
provide accommodation. The crystalline lens matrix is completely
lost and the integrity of the capsular sac is reduced by the
capsularhexis. The "shrink-wrap" of the capsular sac around the IOL
can damage the zonule complex, and thereafter the ciliary muscles
may atrophy. Thus, conventional IOUs, even those that profess to be
accommodative, may be unable to provide sufficient axial lens
spatial displacement along the optical axis or lens shape change to
provide an adequate amount of accommodation for near vision.
[0007] It is known to implant a combination of lenses to address
refraction errors in the existing lens in the case of phakic IOLs
or improve the refractive results of standard IOL after cataract
surgery in the case of pseudophakic patients. These "piggyback"
IOLs can be placed anterior to the previously implanted IOL or
natural lens to improve the refractive results of cataract surgery
in the case of pseudophakes or to change the refractive status of
the eye in the case of phakic eyes, usually to correct high myopia.
Generally, these lenses are implanted in the sulcus and are
non-accommodating.
SUMMARY
[0008] In one aspect, described herein is an intraocular lens
including a shape changing optical element; a force translation
element having a first end region coupled to the optical element
and a second end region extending towards a ciliary structure, and
an attachment portion coupled to the second end region of the force
translation element and configured to contact the ciliary
structure. The force translation element is configured to
functionally transmit movements of the ciliary structure into a
force exerted upon the optical element to effect an accommodating
and a disaccommodating change of the optical element.
[0009] The force translation element can be customized for fit
during implantation. The mechanism for customizing the fit can
include sliding, twisting, turning, cutting, rolling, expanding,
bending, and applying energy to the force translation element. The
force translation element can be coated with an expandable
material. At least one of the optical element, the force
translation element, and the attachment portion can be coated with
an agent having biological activity such as heparin, a steroid and
rapamicin. The first end region of the force translation element
can be coupled to an equator of the optical element. A plurality of
force translation elements can be coupled near an equator of the
optical element.
[0010] The attachment portion can be configured to contact the
ciliary structure. The attachment portion can be configured to abut
and not penetrate the ciliary structure. The ciliary structure can
be the ciliary muscle, the ciliary body, a ciliary process, and a
zonule. The attachment portion can be formed of an elastic
material. The attachment portion can include one or more rods. The
one or more rods can be curved. The attachment portion can include
a three dimensional element that fills a space adjacent the ciliary
structure. The attachment portion can include a fillable element.
The attachment portion can include a glue, hydrogel or fixation
material. The attachment portion can elicit a healing response in
the ciliary structure to induce soft tissue integration of the
attachment portion.
[0011] The optical element can have a power in the range of about
.+-.3 diopters to about .+-.5 diopters. The accommodating change of
the optical element can include a change from an ovoid shape to a
more spherical shape. The accommodating change of the optical
element can include a change in spatial configuration along the
optical axis in an anterior direction. The force translation
element can be formed of a material generally harder than a
material of the optical element. The second lens can be positioned
within the capsular bag of the eye. The optical element can be
positioned anterior to the second lens. The optical element can be
positioned within the capsular bag of the eye. The optical element
can be positioned posterior to the iris. The optical element can be
positioned anterior to the iris. The second lens can include an
implanted intraocular lens.
[0012] The lens can further include a haptic coupled to and
extending outward from the optical element. The haptic can be
positioned within a sulcus. The force translation element can be
coupled to the haptic. The force translation element can be coupled
to the ciliary body to push on the optical element.
[0013] The force translation element can be coupled to the ciliary
body to pull on the optical element. The accommodating and
disaccommodating change can include a shape change effected over
the entire surface of the optical element. The accommodating and
disaccommodating change can include a shape change effected over a
portion of the optical element. The portion can preferentially
bulge upon an accommodating change. The shape change effected over
a portion can be due to a difference in modulus of the portion of
the optical element compared to the modulus of another portion of
the optical element. A center region of the optical element can
include a lower modulus material than an outer region of the
optical element. The lower modulus material can give way causing a
bulge and a change in dioptric effect.
[0014] These general and specific aspects may be implemented using
the devices, methods, and systems or any combination of the
devices, methods and systems disclosed herein. Other features and
advantages should be apparent from the following description of
various embodiments, which illustrate, by way of example, the
principles of the described subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 depicts a cross-sectional, schematic view of an eye
showing an embodiment of an intraocular lens implanted anterior to
another intraocular lens implanted in the capsular bag;
[0016] FIG. 2 depicts a cross-sectional, schematic view of the lens
of FIG. 1 during accommodation;
[0017] FIG. 3A depicts a schematic view of an embodiment of a
lens;
[0018] FIG. 3B depicts a schematic view of another embodiment of a
lens;
[0019] FIG. 3C depicts a cross-sectional view of the optical
element of the lens of FIG. 3A;
[0020] FIG. 3D depicts a cross-sectional view of the optical
element of the lens of FIG. 3B;
[0021] FIG. 4 depicts a schematic view of another embodiment of a
lens having haptics and force translation elements;
[0022] FIGS. 5A-5B depict schematic top and side views,
respectively of another embodiment of a lens having haptics and
force translation elements;
[0023] FIGS. 6A-6B depict schematic views of force translation
elements; and
[0024] FIGS. 7A-7B depict schematic views of additional embodiments
of a lens having a hydrogel coating.
[0025] It should be appreciated that the drawings herein are
exemplary only and are not meant to be to scale.
DETAILED DESCRIPTION
[0026] There is a need for improved methods and devices for the
treatment of presbyopia in phakic and pseudophakic patients. The
intraocular lenses described herein can be switched back and forth
repeatedly between accommodation to disaccommodation, just as in a
young accommodative natural eye.
[0027] The term shape changing optical element refers to an optical
element that is made of material that enables the optical element
to alter its shape, e.g., become one of more spherical in shape,
thicker to focus on a closer object; or become more ovoid in shape,
thinner to focus on a more distant and thus alter the optical
element's respective optics (alter the dioptric power of the
resulting optical element). The shape change can be effected over
the entire surface of the optical element, or just over a portion
of the optical element, such as by having a preferential change or
"bulge" in a portion of the optical element. This can be achieved
by varying the modulus of portions of the optical element. For
example, the center region may be a lower modulus material than the
outer region of the optical element in which case when the ciliary
body accommodates and the force will be translated to the center of
the optical element preferentially to cause a "bulge" that will
provide the desired dioptric effect.
[0028] Alternatively, the optical element may be a dual optic that
is designed to translate relative to each other to increase or
decrease the dioptric power of the system.
[0029] The term accommodating shape refers to the shape of the
optical element when at least one of the contraction of the ciliary
muscle of the mammalian eye, the lower tension of the zonules of
the mammalian eye and a decrease in the vitreous pressure in the
eye occur to effect a focusing upon a closer object. An
accommodating shape is generally more spherical than the
disaccommodating shape.
[0030] The term disaccommodating shape refers to the shape of the
optical element when at least one of the relaxation of the ciliary
muscle of the mammalian eye, the higher tension of the zonules of
the mammalian eye and an increase in the vitreous pressure in the
eye occur to effect a focusing upon a more distant object. A
disaccommodating shape is generally more ovoid than the
accommodating shape.
[0031] The term diopter (D) refers to the reciprocal of the focal
length of a lens in meters. For example, a 10 D lens brings
parallel rays of light to a focus at ( 1/10) meter. After a
patient's natural crystalline lens has been surgically removed,
surgeons usually follow a formula based on their own personal
preference to calculate a desirable diopter power (D) for the
selection of an IOL for the patient to correct the patient's
preoperational refractive error. For example, when a myopia patient
with -10 D undergoes cataract surgery and IOL implantation, the
patient can see at a distance well enough even without glasses.
Generally, this is because the surgeon has taken the patient's -10
D near-sightedness into account when choosing an IOL for the
patient.
[0032] The lenses described herein can mechanically or functionally
interact with eye tissues typically used by a natural lens during
accommodation and disaccommodation such as the ciliary body,
ciliary processes, and the zonules, to effect accommodation and
disaccommodation of the implanted lens. The forces generated by
these tissues are functionally translated to the optical element of
the implanted lens causing a power change to allow a phakic or
pseudophakic patient to more effectively accommodate.
[0033] The intraocular lenses described herein can be implanted in
the eye to replace a diseased, natural lens. The intraocular lenses
described herein can also be implanted as a supplement of a natural
lens (phakic patient) or an intraocular lens previously implanted
within a patient's capsular bag (pseudophakic patient). The lenses
described herein can be used in combination with intraocular lenses
described in U.S. Patent Publication Nos. 2009/0234449 and
2009/0292355, which are each incorporated by reference herein in
their entirety. As such, the lenses described herein can be used
independently or as so-called "piggyback" lenses. Piggyback lenses
can be used to correct residual refractive errors in phakic or
pseudophakic eyes. The primary IOL used to replace the natural lens
is generally thicker and has a power that can be in the range of
.+-.20 D. The thicker, larger power lenses generally have less
accommodation. In contrast, the supplemental lens need not possess
a full range of diopters (D). The supplemental lens can be
relatively thin compared to the primary IOL and can undergo more
accommodation. Shape change and movement of the thinner lens is
generally more easily accomplished relative to a thick primary
lens. It should be appreciated, however, that the lenses described
herein can be used independently and need not be used in
combination as piggyback lenses with the natural lens or an
implanted IOL.
[0034] FIG. 1 depicts a cross-sectional view of an eye 5 including
the cornea 10, iris 15, sulcus 20, ciliary body 25, ciliary
processes 27, zonules 30 and the capsular bag 35 including an IOL
40 implanted in the capsular bag 35. A lens 100 is shown positioned
within the sulcus 20 anterior to the IOL 40. It should be
appreciated that although the lens 100 is shown positioned within
the sulcus 20 and posterior to the iris 15 that it can also be
positioned anterior to the iris 15 within the anterior chamber 45.
The lens 100 can also be positioned within the capsular bag 35 just
in front of the previously implanted IOL 40 or natural lens.
[0035] The lens 100 can include a central optical element 105 and
at least two force translation elements 110 extending outward from
the optical element 105 (see FIG. 2). The optical element 105 can
be an adjustable lens such that the optical properties can be
manipulated after implantation, as will be described in more detail
below. The force translation elements 110 can functionally couple
with at least one of the ciliary structures such as the ciliary
body 25, ciliary processes 27, and/or the zonules 30 such that
movements of these tissues during accommodation and
disaccommodation are translated to the optical element 105 via the
force translation elements 110 to cause at least a change in shape
or change in position of the optical element 105. The lens 100 can
further include at least two haptics 115 coupled to and extending
outward from the optical element 105. The haptics 115 can be
positioned within the,sulcus 20 to further aid in the anchoring of
the lens in the eye.
[0036] FIG. 2 depicts a cross-sectional, schematic view of the lens
100 during accommodation. The ciliary body 25 is a generally
circular structure. The ciliary muscle is a sphincter shaped like a
doughnut. In natural circumstances, when the eye is viewing an
object at a far distance, the ciliary muscle within the ciliary
body 25 relaxes and the inside diameter of the ciliary muscle gets
larger. The ciliary processes 27 pull on the zonules 30, which in
turn pull on the lens capsule 35 around its equator. This causes a
natural lens to flatten or to become less convex, which is called
disaccommodation. During accommodation, the muscles of the ciliary
body 25 contract and the inside diameter of the ciliary muscle gets
smaller. The ciliary processes 27 release the tension on the
zonules 30 and the lens takes on its natural, more convex shape
such that the eye can focus at near distance.
[0037] Without limiting this disclosure to any particular theory or
mode of operation, the eye is believed to act on the implanted
intraocular lenses described herein as follows. The force
translation elements 110 are implanted such that they are in
contact with at least one of the ciliary structures (i.e. zonules
30, ciliary processes 27 and/or ciliary body 25). The contraction
of the ciliary muscle and inward movement of the tissues towards
the optical axis O applies a force against the force translation
elements 110 (see FIG. 2). The force translation elements 110
transfer the force to the optical element 105, which can take on a
more spherical shape suitable for near vision. This contraction of
the ciliary muscle and inward movement of the ciliary body 25 can
also result in a change in the spatial configuration of the lens
100 such that it axially displaces along the optical axis O
forwardly in an anterior direction (distance D) relative to the
natural lens or a previously implanted IOL 40. Both the more
spherical shape and the anterior movement away from IOL 40 can
cause an increase in power needed for accommodation and near vision
focus.
[0038] As mentioned, the force translation elements 110 can be
configured to cooperate with at least one of the ciliary body 25,
ciliary processes 27, or the zonules 30 to change the shape of the
optical element 105. It should be appreciated that the vitreous
pressure in the eye can also be involved in the accommodating shape
of the optical element 105. Further, if the lens 100 is implanted
anterior to the iris 15, for example within the anterior chamber
45, the structures of the anterior chamber angle can also affect
the accommodating shape change of the optical element 105.
[0039] FIGS. 3A-3B depict an embodiment of an intraocular lens 100
having an optical element 105 and two force translation elements
110 extending outward from near the equator of optical element 105.
It should be appreciated that the force translation elements 110
can also extend outward from other regions of the optical element
105. For example, the force translation element 110 can be coupled
nearer to one or more of the poles of the optical element 105. The
force translation elements 110 can be coupled to the optical
element 105 or the force translation elements 110 can be coupled to
and extend from haptics 115, if present. It should also be
appreciated that the lens 100 can have more than two force
translation elements 110 such as three, four, five or more force
translation elements 110. In one aspect, the force translation
elements 110 can extend from the optical element 105 on opposing
sides of the optical axis O.
[0040] When implanted in the eye, an end of the force translation
elements 110 can be positioned adjacent the ciliary body 25 on
either side of the eye. The force translation elements 110 can be
adapted to translate force applied by the adjacent tissues to the
optical element 105 to cause a shape change or a relative spatial
change or both. The force translation elements 110 can be generally
formed of a harder material than that of the optical element 105. A
change in hardness or durometer can be accomplished via a change in
material. For example, a higher durometer material can be used for
the force translation elements 110 than the material used for the
optical element 105. For example, the force translation elements
110 can be made from silicone and the optical element 105 can be
made from a softer hydrogel. Alternatively, the materials of the
force translation elements 110 and the optical element 105 can be
the same, but the hardness different. Hardness can be determined or
quantized using the Shore A or Shore D scale. The various materials
considered herein for forming the components of the lens 100 are
discussed in more detail below.
[0041] As mentioned, the optical element 105 can change to a more
spherical shape during accommodation upon narrowing of the inside
diameter of the ciliary body 25 by mechanically and functionally
connecting with the movement of one or more of the ciliary tissues.
As shown in FIG. 3A, contraction of the muscles of the ciliary body
25 can create a force in the direction of arrows A, which is then
applied to the force translation elements 110. The force
translation elements 110 translate that force to the optical
element 105 (arrows B). Depending on the design of the optical
element 105, the optical element 105 can change shape, for example,
along arrows C shown in FIGS. 3A and 3B into a more spherical,
accommodated shape to view a near object. If a far object is to be
viewed, the optical element 105 can return to its resting,
disaccommodating shape, which is more flat upon relaxation of the
ciliary body 25 and return to its posterior-most resting
configuration decreasing its effective power because the force
translation elements 115 are no longer being urged inward by the
surrounding tissues.
[0042] The optical element 105 can be designed to include a variety
of features that cause an accommodative change in power. The
optical element 105 can include internal cleavage planes to cause
bulging in the center of the optical element 105 when the ciliary
body 25 and its associated tissues are in the accommodative
position increasing the power in the center of the optical element
105 (as shown in FIG. 3B). The optical element 105 can also be
fluid-filled such that movement of the ciliary body 25 and its
associated tissues can cause the fluid to move and bulge near the
center of the optical element 105 increasing its power. The
configuration of the optical element 105 can vary as is described
in U.S. Patent Publication Nos. 2009/0234449 and 2009/0292355,
which are each incorporated by reference herein in their
entirety.
[0043] As an example, FIG. 3C illustrates an optical element 105
having an outer lens portion 305 and a core lens portion 307. The
outer lens portion 305 can be structured to include a center
section 320 that can have a reduced thickness or hardness. The
center section 320 can surround the optical axis O of the optical
element 105 and can be located on or near the anterior face 310
thereof. When the lens 100, and in particular the optical element
105, is compressed, for example by an inward force at peripheral
regions 325 and 330 applied by the force translation elements 110,
the optical element 105 can be reshaped by an outward bowing of the
anterior face 310. This inward force by the force translation
elements 110 is due to the compressive force applied to the force
translation elements 110 by at least one of the ciliary body 25,
ciliary processes 27, or zonules 30 depending on how the lens 100
is implanted.
[0044] As shown in FIG. 3D, the outward bowing or reshaping can be
especially pronounced at region 335. This can be due to a reduced
thickness of the outer lens portion 305 at center section 320. The
reduced thickness can be relatively more prone to give way from the
internal pressure of the core lens portion 307 upon inward force
applied at the peripheral regions 325, 330. The core lens portion
307 can extend forward, as seen for example in the central region
335 in FIG. 3D. The center section 320 can also include a material
of reduced hardness or increased elasticity to be more prone to
give way from the internal pressure.
[0045] The extended central region 335 of optical element 105 can
provide near vision correction power. The remainder of the outer
portion 305 outside the center section 320 can have a greater
thickness that can be more resistant to reshaping under such
compression at the peripheral regions 325, 330. As such, the
annular region 340 of optical element 105 extending radially
outward of center section 335 can continue to provide distance
vision correction power. The regions 335 and 340 of optical element
105, under compression, can provide both near and distance vision
correction powers, respectively. In other words, the anterior
surface 310 of optical element 105 can be a multifocal surface when
the optical element 105 is under compression. In contrast, when the
optical element 105 is in the resting position as shown in FIG. 3C,
the anterior surface 310 can be a monofocal surface.
[0046] FIG. 3D illustrates an alternative embodiment of the lens
100, which is substantially the same as that shown in FIG. 3C,
except for a different construction of the outer portion 305. The
center section 320 can be made of a material that is relatively
more susceptible to outward bowing than is the peripheral region
surrounding it. The center section 320 can be injection molded in
combination with the peripheral regions surrounding it to provide a
relatively seamless and uninterrupted anterior face 310, at least
in the rest position of the lens 100. When the peripheral regions
325 and 330 are squeezed towards the optical axis O, the core lens
portion 307 can be placed in compression thus forcing the center
section 320 in the anterior direction as shown in the extended
region 335. The material of the outer portion 305 can be generally
consistent, though the center section 320 can have a different
stiffness or elasticity that causes it to bow outward farther than
the surrounding region.
[0047] The extent to which central region 335 extends forwardly,
and therefore the magnitude of the near vision correction power
obtainable by the optical element 105, can depend on a number of
factors, such as the relative thickness, hardness, stiffness,
elasticity etc. of center section 320, the overall structure of the
outer portion 305 and/or the inner portion 307, the material of
construction of the outer portion and/or the inner portion, the
amount of force that the eye in which lens 100 is placed can exert
on the lens 100 and the like factors. The amount or degree of near
power correction obtainable from lens 100 can be controlled, or at
least partially controlled, by varying one or more of these
factors.
[0048] The embodiments of the optical element 105 described thus
far, have a resting configuration when no forces being applied that
are lower power or more flat. During accommodation when the ciliary
body pushes against the force translation elements 110, the optical
element 105 can take on a more spherical, higher power
configuration. It should be appreciated, however, that the optical
element 105 can also mimic more closely a natural lens. In this
embodiment, the optical element 105 is high power or more spherical
at a resting configuration when no forces are being applied to it.
In this embodiment, the ciliary body relaxes during
disaccommodation and applies tension to the force translation
elements 110 which translate a force on the optical element 105
such that the optical element 105 flattens for low power and
returns to the spherical configuration during accommodation with
the ciliary body contracts. In such a configuration, the force
translation element 110 could incorporate a more robust mechanism
of attachment to the tissues.
[0049] The lenses described herein have the ability, in cooperation
with the eye, to be reshaped to provide for both distance focus and
near focus, and to be returned to its first configuration in which
only distance focus is provided. The amount of force required to
effect a shape change in the optical element 105 is generally less
than that of moving the optical element 105 axially along the
optical axis to achieve the desired change in diopter. The change
in diopter achieved by a shape change is also generally larger than
the change in diopter achieved by an axial displacement. The
optical element 105 can have a power in the range of about .+-.1 D
to about .+-.4 D or about .+-.5 D or about .+-.6 D. In an
embodiment, the underlying power of the lens can be within the
range of about .+-.5 D. In an embodiment, the underlying power of
the lens can be within the range of about .+-.3 D. It should be
appreciated that the optical element 105 can also have a larger
power in the range of about .+-.20 D.
[0050] The force translation elements 110 contact the eye tissue by
way of an attachment portion 120 (see FIG. 4). The mode of
attachment provided by the attachment portion 120 can vary.
Generally, the attachment portion 120 avoids piercing or causing
trauma to the ciliary body 25. The attachment portion 120 can
interfere with the tissues such that movement of the ciliary body
25, ciliary processes 27 or zonules 30 can be transferred through
the force translation elements 110 to the optical element 105
without causing trauma to the tissues themselves. The attachment
portion 120 can be formed of a material that is generally softer or
more elastic than the force translation elements 110. This provides
a more forgiving surface against which the tissues can abut such
that piercing of the tissues and inadvertent trauma are avoided.
This also allows for the attachment portion 120 to provide a better
fit in that there is some room for error in the overall length and
size of the lens 100 and its components. The elasticity of the
material can also for a one-size-fits-all approach such that even
if the measurement was not exact, the length of the translation
elements 110 and attachment portions 120 would be sufficient to
effect shape change of the optical element 105 when needed while
avoiding constant shape change or tissue damage.
[0051] As an example, the attachment portion 120 can be a generally
rigid, elongate rod or plurality of rods 125 (see FIG. 6A)
positioned between and interfering with one or more zonules 30 or
ciliary processes 27. The rods 125 can be straight, curved, or have
a bend at a particular angle relative to the longitudinal axis of
the force translation element 110. As an example, the plurality of
rods 125 can be curved such that they form a cup that can
interdigitate between the ciliary processes 27 and/or zonules 30.
The plurality of rods 125 can extend to the ciliary body 25 with or
without making contact with the ciliary body 25.
[0052] The attachment portion 120 can also have a three-dimensional
shape that fills a space surrounding the zonules 30 or ciliary
processes 27 or that fills the space above the ciliary body 25. As
an example, the attachment portion 120 can have a wedge shape such
that the force translation elements 110 extends between the ciliary
processes 27 and the attachment portion 120 wedges up against the
ciliary body 25. The attachment portion 120 can also include a
three-dimensional expandable element 123 such as a bag, balloon or
bulb coupled near an end of the force translation element 110. FIG.
6B illustrates an attachment portion 120 of an embodiment of a
force translation element 110 having a plurality of rods 125. One
or more of the plurality of rods 125 can include an expandable
element 123 near a distal end region. A channel 127 can extend
through an interior of the force translation element 110 into at
least a portion of each of the plurality of rods 125 such that the
channel 127 communicates with the expandable elements 123. A fluid
(including a gas or liquid or gel) can be injected into a port or
other structure positioned along the force translation element 110
and into the channel 127 such that the expandable element 123
expands outward into one or more directions. The position of the
port can vary, but is generally located so that it does not
interfere with the optical part of the device. In some embodiments,
the expandable elements 123 can expand three-dimensionally such
that they fill the space between the ciliary processes 27 or around
the ciliary body 25 or on top of the ciliary processes 27 and
covering the ciliary body 25. The expandable elements 123 can be
filled with a material to provide the desired three-dimensional
shape, such as silicone oil, hydrogel, saline or other
material.
[0053] As shown in FIGS. 7A and 7B, the attachment portion 120 can
include a coating 129 made of a material such as glue, hydrogel or
other flowable material (see FIGS. 7A-7B). The coating 129 can fix
the attachment portion 120 in place. The coating 129 can also act
to fill a three-dimensional space surrounding a particular tissue
site to help secure the lens 100. The coating 129 can be injected
through a port and into a channel 127 extending through the
interior of the force translation element 110 into the attachment
portion 120. One or more openings 131 positioned near a distal end
region of the attachment portion 120 can allow for the material to
flow from the channel 127 to an external surface of the attachment
portion 120 therein coating the external surface.
[0054] Soft tissue integration of the attachment portion 120 can be
achieved by positioning the attachment portion 120 in direct
contact with one or more of the ciliary tissues such that a minimal
level of tissue irritation is achieved to set off a healing
response. Upon tissue irritation, a minor inflammatory response
ensues that is enough to cause the attachment portion 120 to become
incorporated into the ciliary processes 27 or ciliary body 25
without interfering with the physiological role of the tissues.
Tissue growth into and/or around the attachment portion 120 and
integration of the device into the tissue can be achieved without
piercing or causing trauma to the tissue, for example affecting its
ability to produce aqueous humor.
[0055] It should also be appreciated that a combination of
attachment portions 120 with or without soft tissue integration are
considered herein. For example, one or more expandable elements 123
can be coupled to an end region of the attachment portion 120 that
are also filled and coated with a material that provides fixing
power such as glue or another flowable material. Further, the
expanded shape of the expandable element 123 can provide certain
characteristics to the attachment portion 120. For example, the
expandable element 123 when filled can form a wedge shape such that
it can be used as described above to wedge up against the ciliary
body 25 or between the ciliary processes 27 when filled upon
implantation. The expandable elements 123 can also provide a degree
of customization to the attachment portion 120 such that the fit
can be modified during implantation. The expandable element 123 can
be positioned at a distal end region of the attachment portion 120
such that upon filling the expandable element 123 provides a
customized size that provides the most beneficial fit to the device
for a particular patient.
[0056] The force translation elements 110 and/or the attachment
portion 120 of the lens can be customized for length, angle and
position relative to various structures of the eye. For example,
the angle at which the force translation elements 110 extend from
the optical element 105 can play a role in the distance D away from
the natural lens or previously implanted IOL that the lens 100 is
implanted, which in turn can impact the focal power. Further, the
length of the force translation elements 110 can affect whether or
not the force translation elements 110 physically contact the
ciliary body or neighboring tissues. If the force translation
elements 110 are too long and make contact with the ciliary body in
a resting state it is possible that the tissue structures can be
damaged or the optical element 105 can remain in a constant state
of accommodation. Alternatively, if the force translation elements
110 are too short it is possible that not enough shape change would
be achieved upon ciliary muscle contraction to effect proper
accommodation. It is desirable, therefore, to customize and adjust
the length, angle, position or other characteristics of the force
translation elements 110 and/or the attachment portion 120 upon
implantation. It should be appreciated that the customization can
take place prior to implantation if the appropriate measurements
are known in advance of the procedure. Alternatively, customization
can take place on-the-fly during implantation or after implantation
of the lens 100.
[0057] The length of each force translation element 110 can be
adjusted by a variety of mechanisms including sliding, twisting,
turning, cutting, rolling, expanding, etc. For example, the force
translation element 110 can be unrolled upon implantation in an
outward direction from the optical element 105 until the optimum
length is achieved for proper accommodation to occur upon ciliary
muscle contraction. Alternatively, the force translation element
110 can be twisted to reduce the overall length it extends outward
from the optical element 105. The force translation element 110 can
also be manually cut to an appropriate length.
[0058] The force translation element 110 and/or the attachment
mechanism 120 can be formed of a shape-memory material or other
stimuli-responsive material that has the capability of changing
shape under an external stimulus. For example, the stimulus can be
a temperature change or exertion of an external force (compression
or stretching). The shape-memory material can be activated to
extend to a pre-set length, shape or angle upon application of
energy such as heat. The force translation element 110 and/or the
attachment mechanism 120 can be formed of an elastic or
super-elastic material such as Nitinol.
[0059] The force translation element 110 and/or the attachment
mechanism 120 can be formed of or coated with a material that
expands upon implantation in the eye. The material can expand along
a longitudinal axis of the structure or the material can expand in
three-dimensionally so as to fill a void adjacent the component.
For example, the expanded material can fill a void adjacent the
force translation element 110 and/or attachment mechanism 120 such
as the region between the ciliary processes. Expandable materials
can include, but is not limited to for example, hydrogel, foam,
lyophilized collagen, swelling acrylic, or any material that gels,
swells, or otherwise expands upon contact with body fluids. The
expandable material can be positioned such that it causes the force
translation element 110 to move from a retracted state to an
expanded state such that it extends between or against an
anatomical structure. The expandable material can also coat the
attachment mechanisms 120 and aid in the attachment mechanism 120
taking on a preferred shape. For example, the attachment mechanism
120 can be a plurality of rods coated by the expandable material
such that upon implantation the rods are forced outward away from
one another.
[0060] As mentioned above, the force translation element 110 can be
coupled to a region of the haptic 115. In an embodiment, the haptic
115 can be positioned within the sulcus and the force translation
element 110 can be angled downward to reach the ciliary body. The
force translation element 110 can be twisted around the haptic 115
to achieve a desired length. Alternatively, the force translation
element 110 can be coupled to the haptic 115 in such a way that it
can be manually moved along the length of the haptic 115 until the
desired extension towards the ciliary body is achieved.
[0061] The material of the components of the lenses described
herein can vary. As mentioned above, the force translation elements
110 and haptics 115, if present, are generally formed of a material
having a harder durometer than the optical element 105 or the
attachment mechanism 120 such that they can translate forces
applied by the surrounding tissues to effect shape change and/or
change in spatial configuration of the optical element 105. The
force translation elements 110, attachment mechanism 120, haptics
115 (if present) and optical element 105 can each be the same
material, but may have a hardness that differs to achieve the
desired functional characteristics when implanted.
[0062] Suitable materials for the preparation of the optical
element 105 disclosed herein vary and include materials that are
known in the art. As an example, materials can include, but are not
limited to, acrylic polymers, silicone elastomers, hydrogels,
composite materials, and combinations thereof. Materials considered
herein for forming various components are described in U.S. Patent
Publication Nos. 2009/0234449 and 2009/0292355, which are each
incorporated by reference herein in their entirety. The optical
element 105 can also be formed from a photosensitive silicone to
facilitate post-implantation power adjustment as taught in U.S.
Pat. No. 6,450,642, entitled LENSES CAPABLE OF POST-FABRICATION
POWER MODIFICATION, the entire contents of which are hereby
incorporated by reference herein.
[0063] Suitable materials for the production of the subject force
translation elements 110 include but are not limited to foldable or
compressible materials or hard materials, such as silicone
polymers, hydrocarbon and fluorocarbon polymers, hydrogels, soft
acrylic polymers, polyesters, polyamides, polyimides, polyurethane,
silicone polymers with hydrophilic monomer units,
fluorine-containing polysiloxane elastomers and combinations
thereof.
[0064] A high refractive index is a desirable feature in the
production of lenses to impart high optical power with a minimum of
optic thickness. By using a material with a high refractive index,
visual acuity deficiencies may be corrected using a thinner
IOL.
[0065] The optical element 105 can also be formed from layers of
differing materials. The layers may be arranged in a simple
sandwich fashion, or concentrically. In addition, the layers may
include a series of polymer layers, a mix of polymer and metallic
layers, or a mix of polymer and monomer layers. In particular, a
Nitinol ribbon core with a surrounding silicone jacket may be used
for any portion of the lens 100 except for the optics; an
acrylic-over-silicone laminate may be employed for the optics. A
layered construction may be obtained by pressing/bonding two or
more layers together, or deposition or coating processes may be
employed.
[0066] Where desired, various coatings are suitable for one or more
components of the lens 100. A heparin coating may be applied to
appropriate locations to prevent inflammatory cell attachment (ICA)
and/or posterior capsule opacification (PCO); possible locations
for such a coating include the optical element 105. Coatings can
also be applied to the lens 100 to improve biocompatibility; such
coatings include "active" coatings like P-15 peptides or RGD
peptides, and "passive" coatings such as rapamicin, steroids,
heparin, and other mucopolysaccharides, collagen, fibronectin and
laminin. Other coatings, including hirudin, Teflon, Teflon-like
coatings, PVDF, fluorinated polymers, and other coatings which are
inert may be employed to increase lubricity at locations on the
lens system, or Hema or silicone can be used to impart hydrophilic
or hydrophobic properties to portions of the lens 100.
[0067] One or more of the lens components can also be coated with a
therapeutic or other agent that ameliorates a symptom of a disease
or disorder including, for example, steroids, small molecule drugs,
proteins, nucleic acids, polysaccharides, and biologics or
combination thereof. Therapeutic agent, therapeutic compound,
therapeutic regimen, or chemotherapeutic include conventional drugs
and drug therapies, including vaccines, which are known to those
skilled in the art. Therapeutic agents include, but are not limited
to, moieties that inhibit cell growth or promote cell death, that
can be activated to inhibit cell growth or promote cell death, or
that activate another agent to inhibit cell growth or promote cell
death. Optionally, the therapeutic agent can exhibit or manifest
additional properties, such as, properties that permit its use as
an imaging agent, as described elsewhere herein. Exemplary
therapeutic agents include, for example, cytokines, growth factors,
proteins, peptides or peptidomimetics, bioactive agents,
photosensitizing agents, radionuclides, toxins, anti-metabolites,
signaling modulators, anti-cancer antibiotics, anti-cancer
antibodies, angiogenesis inhibitors, radiation therapy,
chemotherapeutic compounds or a combination thereof. The drug may
be any agent capable of providing a therapeutic benefit. In an
embodiment, the drug is a known drug, or drug combination,
effective for treating diseases and disorders of the eye. In
non-limiting, exemplary embodiments, the drug is an antiinfective
agent (e.g., an antibiotic or antifungal agent), an anesthetic
agent, an anti-VEGF agent, an anti-inflammatory agent, a biological
agent (such as RNA), an intraocular pressure reducing agent (i.e.,
a glaucoma drug), or a combination thereof. Non-limiting examples
of drugs are provided below.
[0068] In an embodiment, the lens 100 and/or the mold surfaces are
subjected to a surface passivation process to improve
biocompatibility. This may be done via conventional techniques such
as chemical etching or plasma treatment.
[0069] Once formed, the subject force translation elements 110 can
be permanently attached to optical element 105 by numerous methods
including but not limited to fastening within a pre-formed optic
slot using glue, staking, plasma treatment, friction, or like means
or combinations thereof.
[0070] Furthermore, appropriate surfaces (such as the outer
edges/surfaces of the contacting elements, accommodating elements,
etc.) of the lens components can be textured or roughened to
improve adhesion to the adjacent tissue surfaces. This can be
accomplished by using conventional procedures such as plasma
treatment, etching, dipping, vapor deposition, mold surface
modification, etc.
[0071] In an embodiment, the selected material and lens
configuration is able to withstand secondary operations after
molding/casting such as polishing, cleaning and sterilization
processes involving the use of an autoclave, or ethylene oxide or
radiation. After the mold is opened, the lens can undergo
deflashing, polishing and cleaning operations, which typically
involve a chemical or mechanical process, or a combination thereof.
Some suitable mechanical processes can include tumbling, shaking
and vibration; a tumbling process may involve the use of a barrel
with varying grades of glass beads, fluids such as alcohol or water
and polishing compounds such as aluminum oxides. Process rates are
material dependent; for example, a tumbling process for silicone
can utilize a 6'' diameter barrel moving at 30-100 RPM. It is
contemplated that several different steps of polishing and cleaning
may be employed before the final surface quality is achieved.
[0072] A curing process may also be desirable in manufacturing the
components of the lens 100. If the lens is produced from silicone
entirely at room temperature, the curing time can be as long as
several days. If the mold is maintained at about 50.degree. C., the
curing time can be reduced to about 24 hours. If the mold is
preheated to 100-200.degree. C., the curing time can be as short as
about 3-15 minutes. The time-temperature combinations vary for
other materials.
[0073] It should be appreciated that the lenses described herein
can be implanted in a phakic or pseudophakic patient. In an
exemplary implantation procedure, an IOL implantation is performed
anterior to the natural crystalline lens or anterior to a
previously-implanted IOL. Although the implantation procedure can
vary, one procedure can be performed as follows. One or more clear
corneal incisions can be formed. A first incision can be formed for
IOL insertion and a second incision can be formed for manipulation
and assistance of positioning the IOL. A viscoelastic substance can
be inserted into the eye, such as to at least partially fill the
anterior chamber and/or an area between the iris and the
intra-capsular IOL. The IOL can be inserted into position in the
eye and the force-translation elements inserted into a desired
position and connected to the ciliary body. One or more IOL can be
inserted into the ciliary sulcus and the viscoelastic substance
washed out of the eye. A check may then be performed to verify that
the corneal incisions are appropriately sealed. Any of a variety of
instruments may be used in conjunction with the procedure.
Moreover, it should be appreciated that the aforementioned steps
may be performed in a different order than described above.
[0074] While this specification contains many specifics, these
should not be construed as limitations on the scope of an invention
that is claimed or of what may be claimed, but rather as
descriptions of features specific to particular embodiments.
Certain features that are described in this specification in the
context of separate embodiments can also be implemented in
combination in a single embodiment. Conversely, various features
that are described in the context of a single embodiment can also
be implemented in multiple embodiments separately or in any
suitable sub-combination. Moreover, although features may be
described above as acting in certain combinations and even
initially claimed as such, one or more features from a claimed
combination can in some cases be excised from the combination, and
the claimed combination may be directed to a sub-combination or a
variation of a sub-combination. Similarly, while operations are
depicted in the drawings in a particular order, this should not be
understood as requiring that such operations be performed in the
particular order shown or in sequential order, or that all
illustrated operations be performed, to achieve desirable results.
Only a few examples and implementations are disclosed. Variations,
modifications and enhancements to the described examples and
implementations and other implementations may be made based on what
is disclosed.
* * * * *