U.S. patent application number 15/493039 was filed with the patent office on 2017-08-03 for deformable intraocular lenses and lens systems.
The applicant listed for this patent is ABBOTT MEDICAL OPTICS INC.. Invention is credited to Daniel G. Brady.
Application Number | 20170216021 15/493039 |
Document ID | / |
Family ID | 37667221 |
Filed Date | 2017-08-03 |
United States Patent
Application |
20170216021 |
Kind Code |
A1 |
Brady; Daniel G. |
August 3, 2017 |
Deformable Intraocular Lenses and Lens Systems
Abstract
An intraocular lens includes a deformable optic, a rigid optic,
and a support structure. The deformable optic is disposed about an
optical axis and comprises a solid material and a deformable
surface. The rigid optic is disposed about the optical axis and
comprises a solid material and a rigid surface. The support
structure is operably coupled to at least one of the optics for
pressing the deformable surface and the rigid surface together in
response to or in the absences of an ocular force, whereby at least
a portion of the deformable surface changes shape such that the
optical power of the at least a portion of the deformable surface
and/or the intraocular lens changes by at least 2 Diopter.
Inventors: |
Brady; Daniel G.; (San Juan
Capistrano, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ABBOTT MEDICAL OPTICS INC. |
Santa Ana |
CA |
US |
|
|
Family ID: |
37667221 |
Appl. No.: |
15/493039 |
Filed: |
April 20, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11241586 |
Sep 30, 2005 |
9636213 |
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15493039 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2/1601 20150401;
A61F 2/164 20150401; A61F 2/1613 20130101; A61F 2002/1681 20130101;
A61F 2/1635 20130101; A61F 2250/0018 20130101; A61F 2/1648
20130101 |
International
Class: |
A61F 2/16 20060101
A61F002/16 |
Claims
1-23. (canceled)
24. A method of providing accommodation, comprising: providing an
intraocular lens, comprising: a deformable optic disposed about an
optical axis comprising a solid material and a deformable surface;
a rigid optic disposed about the optical axis comprising a solid
material and a rigid surface; and a support structure operably
coupled to at least one of the optics; implanting the intraocular
lens into the eye of a subject; and configuring the support
structure for pressing the deformable surface and the rigid surface
together in response to an ocular force, whereby at least a portion
of the deformable surface changes shape such that the optical power
of the at least a portion changes by at least 2 Diopter.
25. The method of claim 24, further comprising configuring the
intraocular lens such that the radius of curvature of the
deformable surface increases or decreases in response to the ocular
force while the radius of curvature of the rigid surface remains
substantially fixed.
26. The method of claim 24, further comprising configuring the
intraocular lens so that an optical aberration of at least one of
the deformable optic, the intraocular lens, and the eye is reduced
in the response to the ocular force.
27. The method of claim 24, further comprising configuring the
intraocular lens so that the deformable surface changes from a
substantially spherical surface to an aspheric surface as the
surfaces are pressed together.
28. The method of claim 24, further comprising configuring the
intraocular lens so that the deformable surface changes from a
first radius of curvature to a second radius of curvature different
from the first radius of curvature when the surfaces are pressed
together.
29-40. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of and claims priority to
U.S. application Ser. No. 11/241,586, filed Sep. 30, 2005, the
entire contents of which are incorporated herein by reference in
its entirety.
BACKGROUND OF THE INVENTION
[0002] Field of the Invention
[0003] This invention relates generally to intraocular lenses and
intraocular lens systems, and more specifically to deformable
intraocular lenses and lens systems for providing
accommodation.
[0004] Description of the Related Art
[0005] Monofocal intraocular lenses are now commonly used to
restore vision lost, for example, due to the formation of
cataracts. More recent efforts in the field have concentrated on
restoring or simulating accommodation, the ability of the eye to
provide both near vision and distant vision. One approach to
providing accommodation for an eye in which the natural lens has
been removed is to use a bifocal or multifocal lens that
simultaneously produces two or more foci. For example, a refractive
lens surface may be produced in which different portions of the
surface have different focal lengths, for example, as taught by
Portney in U.S. Pat. No. 5,225,858. Alternatively, Cohen teaches in
U.S. Pat. No. 5,121,979 the use of a bifocal lens comprising a
diffractive phase plate in which the entire lens produces two
different foci corresponding to two different diffractive orders.
Bifocal lenses utilize the ability of a subject's brain to give
preference to the focus corresponding to a selected image.
[0006] Another approach is to provide an intraocular lens that is
directly responsive to the ciliary muscle of the eye. For example,
in U.S. Pat. No. 6,551,354, an intraocular lens is used to produce
accommodation by providing an optic that moves in the anterior
direction when the ciliary muscle contracts. In U.S. Pat. No.
6,616,692, herein incorporated by reference, a first optic having a
negative optical power is combined with a second optic having a
higher optical power than the first optic. The combination of the
first and second optic advantageously reduces the amount of axial
movement in the eye needed to provide accommodation for
intermediate and near vision.
[0007] In another approach, accommodation is provided by using
ciliary muscle contraction to deform at least a portion of the
intraocular lens optic. One potential problem with this approach is
that the shape of the optic surface produced during accommodation
may result in undesirable amounts of optical aberrations, for
example, spherical aberrations.
[0008] Accommodating intraocular lenses are needed that easily and
effectively deform and change shape to provide both distant vision
and near vision in a way that provides design flexibility and/or
reduces optical aberrations.
SUMMARY OF THE INVENTION
[0009] Embodiments of the invention are generally directed to
devices and methods for providing ocular accommodation and more
specifically to ophthalmic devices such as intraocular lenses for
changing the shape of or deforming at least a portion of a
deformable optic surface when pressed together with and/or
separated from the surface of another optic or a surface of the
capsular bag. Such ophthalmic devices may be configured to easily
and effectively deform and change shape to provide both distant
vision and near vision in a way that provides design flexibility
and/or reduces optical aberrations. Embodiments of the invention
also include devices and methods for providing more that one focus,
reducing at least one optical aberration, and/or producing other
desired optical effects when the deformable optic surface is either
pressed together are separated from another optic or a surface of
the capsular bag.
[0010] In one aspect of the invention, an intraocular lens
comprises a deformable optic, a rigid optic and a support
structure. The deformable optic is disposed about an optical axis
and comprises a solid material and a deformable surface. The rigid
optic is disposed about the optical axis and comprises a solid
material and a rigid surface. The support structure is operably
coupled to at least one of the optics and is configured for
pressing the deformable surface and the rigid surface together in
response to an ocular force, whereby at least a portion of the
deformable surface changes shape such that optical power of the at
least a portion of the deformable surface and/or intraocular lens
changes, typically by at least 1 Diopter, preferably between about
2 to about 5 Diopters. Alternatively, the support structure may be
operably coupled to at least one of the optics for pressing the
deformable surface and the rigid surface together in the absence of
ocular forces. In certain embodiments, the at least a portion of
the deformable surface is the entire surface or substantially the
entire surface forming a clear aperture of the deformable surface.
The intraocular lens is preferably configured to have an
accommodative bias or a disaccommodative bias; however, may
alternatively be configured to have neither an accommodative bias
nor a disaccommodative bias.
[0011] At least one of the optics may be configured to have
substantially no optical power, to have a single optical power, or
to provide two or more optical powers or focal points. At least one
of the optics may have an aspheric surface and/or have a multifocal
and/or diffractive surface. The rigid optic may be used to either
increases or decreases radius of curvature of the deformable
surface when the surfaces are pressed together. The rigid optic may
be configured for placement against the posterior capsule of an eye
and to maintain a substantially fixed shape. The rigid surface may
be configured to reduce an optical aberration of at least one of
the deformable optic, the intraocular lens, and the eye when the
surfaces are pressed together.
[0012] The deformable optic may be configured to have either an
accommodative bias or a disaccommodative bias. The deformable optic
has a center thickness along the optical axis when the in a
substantially unstressed state that may change as the rigid and
deformable optics are pressed together. For example the deformable
optic may be adapted to change the center thickness by a factor of
at least 1.1 when the ocular force is in the range of about 1 to 9
grams. In another example, the deformable optic adapted to change
the center thickness by at least 100 micrometers when the ocular
force is in the range of about 1 to 9 grams. The deformable optic
may be made of a first material and the rigid optic is made of a
second material, wherein at least one of the refractive index and
the Abbe number of the first material is different from that of the
second material.
[0013] The intraocular lens may further comprise a stiffening layer
that is stiffer than the deformable optic, where the deformable
optic is typically disposed between the stiffening layer and the
rigid optic. In such embodiment, the deformable optic may be made
of a first material and the stiffening layer is made of a second
material, wherein at least one of the refractive index and the Abbe
number of the first material is different than that of the second
material. Additionally or alternatively, the deformable optic may
further comprise a relief portion for providing a volume into which
material from the deformable optic may expand or enlarge when the
deformable surface is deformed. The relief portion may comprise at
least a portion of a periphery about the deformable optic and/or
one or more voids within the deformable optic.
[0014] The support structure may be configured for placement in at
least one of the sulcus and the capsular bag. The support structure
may comprise one or more haptics. Alternatively or additionally,
the support structure may comprise an optic positioning element
having an anterior segment configured for yieldable engagement with
an anterior capsule of an eye, a posterior segment for yieldable
engagement with a posterior capsule of the eye, and an equatorial
segment disposed between the anterior segment and the posterior
segment. In such embodiments, the support structure may be
constructed to substantially maintain the equatorial segment in
contact with an equatorial portion of the capsule in response to
the ocular force. The rigid optic in such embodiments is typically
operably coupled at an opening in the anterior segment
substantially centered about the optical axis. The rigid optic and
the deformable optic may be configured to have one or more
overlapping openings that allow fluid to flow into and out of the
interior of the optic positioning element.
[0015] In another aspect of the invention, an intraocular lens
comprises a deformable optic, a rigid optic, and a support
structure, wherein the support structure is operably coupled to at
least one of the optics for producing a force that presses the
deformable surface and the rigid surface together in the response
to an ocular force such that at least a portion of the deformable
surface is deformed and substantially conforms to the shape of the
rigid surface.
[0016] In yet another aspect of the invention, only a portion of
the deformable surface changes shape. In such embodiments, the
portion of the deformable optic may be a central portion of the
deformable optic with a diameter that is typically greater than
about 2 mm. Alternatively, the deformable optic is a peripheral
portion of the deformable optic that typically is concave and
typically has an inner diameter that is less than about 4 mm. In
still another aspect of the invention, the intraocular lens does
not comprise a rigid optic and the support structure is operably
coupled to the deformable optic for pressing the deformable surface
and at least one surface of the capsular bag of an eye together in
response to an ocular force, whereby at least a portion of the
deformable surface changes shape.
[0017] In one aspect of the invention, a method of providing
accommodation comprises providing an intraocular lens according to
an embodiment of the present invention and implanting the
intraocular lens into the eye of a subject. The method further
comprises configuring the support structure of the intraocular lens
for pressing the deformable surface and the rigid surface together
in response to or in the absence of an ocular force, whereby at
least a portion of the deformable surface changes shape such that
optical power of the at least a portion of the deformable surface
and/or the intraocular lens changes. The method may additionally
comprise configuring the intraocular lens such that the radius of
curvature of the deformable surface increases or decreases in
response to the ocular force while the radius of curvature of the
rigid surface remains substantially fixed. The method may also
comprise configuring the intraocular lens so that an optical
aberration of at least one of the deformable optic, the intraocular
lens, and the eye is reduced in the response to the ocular force.
The method may further comprise configuring the intraocular lens so
that the deformable surface changes from a substantially spherical
surface to an aspheric surface as the surfaces are pressed together
or when the surfaces or separated. The method may also comprise
configuring the intraocular lens so that the deformable surface
changes from a first radius of curvature to a second radius of
curvature different from the first radius of curvature when the
surfaces are pressed together.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Embodiments of the present invention may be better
understood from the following detailed description when read in
conjunction with the accompanying drawings. Such embodiments, which
are for illustrative purposes only, depict the novel and
non-obvious aspects of the invention. The drawings include the
following 15 figures, with like numerals indicating like parts:
[0019] FIG. 1 is a front view of accommodative intraocular lens
(IOL) according to a first embodiment of the invention.
[0020] FIG. 2 is a side view of the accommodative IOL illustrated
in FIG. 1 shown within an eye in an accommodative state.
[0021] FIG. 3 is a side view of the accommodative IOL illustrated
in FIG. 1 shown within an eye in a disaccommodative state.
[0022] FIG. 4 is a magnified side view of the accommodative IOL
illustrated in FIG. 2.
[0023] FIG. 5 is a magnified side view of the accommodative IOL
illustrated in FIG. 3.
[0024] FIG. 6 is a front view of accommodative IOL according to a
second embodiment of the invention.
[0025] FIG. 7 is a side view of the accommodative IOL illustrated
in FIG. 6.
[0026] FIG. 8 is a side view of accommodative IOL according to a
third embodiment of the invention shown within an eye in an
accommodative state.
[0027] FIG. 9 is a side view of the accommodative IOL illustrated
in FIG. 8 shown within an eye in a disaccommodative state.
[0028] FIG. 10 is a side view of an IOL according to a fourth
embodiment of the invention shown within an eye in a
disaccommodative state.
[0029] FIG. 11 is a side view of the accommodative IOL illustrated
in FIG. 10 shown within an eye in an accommodative state or
partially accommodative state.
[0030] FIG. 12 is a side view of an IOL according to a fifth
embodiment of the invention shown within an eye in a
disaccommodative state or partially disaccommodative state.
[0031] FIG. 13 is flow chart of a method of providing accommodation
to a subject according an embodiment of the invention.
[0032] FIG. 14 is a side view of the accommodative IOL illustrated
in FIG. 7 shown within an eye in a disaccommodative state.
[0033] FIG. 15 is a side view of the accommodative IOL illustrated
in FIG. 7 shown within an eye in an accommodative state.
DETAILED DESCRIPTION OF THE DRAWINGS
[0034] Referring to FIGS. 1 and 2, in certain embodiments, an
intraocular lens (IOL) 20 is configured for placement within a
mammalian eye 22, preferably that of a human subject. Before
providing a more detailed description of the structure and function
of the IOL 20, a brief overview of the eye 22 will be given. The
eye 22 may be divided into an anterior chamber 24 and a posterior
chamber 26. The anterior chamber 24 includes a volume within the
eye 22 that is substantially defined by a cornea 28 and an iris 30.
The posterior chamber 26 contains a capsular bag 32 comprising an
anterior capsule 34 and a posterior capsule 36. Prior to
implantation of the IOL 20 into the eye 22, the capsular bag 32 has
a substantially discoid shape that is defined by a natural lens
(not shown). During surgery, an opening is formed in the anterior
capsule 34 through which the natural lens is removed.
[0035] The posterior chamber 26 may be defined as the volume within
the eye 22 that is disposed between the iris 30 and the posterior
surface 36 of the capsular bag 32. The capsular bag 32 is
surrounded by a series of zonular fibers (called zonules) 37 that
are disposed between and connect the capsular bag 32 and a ciliary
muscle 38. The posterior chamber 26 also contains a sulcus 39, a
region around a perimeter of the posterior chamber 26 that is
disposed between the iris 30 and the ciliary muscle 38.
[0036] The cornea 28 may be used in combination with either the
natural lens (prior to surgery) or the IOL 20 (after surgery) to
form images on the retina (not shown) of the eye 22. When the
natural lens is present, the shape and position of the capsular bag
32 is used to adjust the amount of optical power produced by the
eye 22, thus allowing the subject to focus on both relatively near
and relatively distant objects. In order to accommodate or focus on
relatively near objects, ocular forces are produced by contraction
of the ciliary muscle 38 that release the tension on zonules 37 and
allow the capsular bag 32 and the natural lens to obtain a more
oval shape.
[0037] As used herein, the term "ocular force" means any force
produced by the eye of a subject that stresses, moves, or changes
the shape of the natural lens of the eye or of at least a portion
of an intraocular lens that is placed into the eye of a subject.
The ocular force acting on the lens (either a natural lens or an
IOL) may be produced, for example, by the state or configuration of
the ciliary body (e.g., contracted or retracted), changes in the
shape of the capsular bag, stretching or contraction of one or more
zonules, vitreous pressure, and/or movement of some part of the eye
such as the ciliary body, zonules, or capsular bag, either alone or
in combination.
[0038] The ocular force acting on the IOL 20 may be produced when
the ciliary muscle 38 is either contracted or retracted, depending
upon the design of the IOL 20 and/or the state of the eye 22 when
the IOL 20 is implanted into and secured within the eye 22 (e.g.,
an accommodative state or a disaccommodative state). For example,
the IOL 20 may be configured to provide near vision to a subject
when the IOL 20 is in a natural or unstressed state and an ocular
force is produced on the IOL 20 when the ciliary muscle 38 is
retracted. In such embodiments, an ocular force may be used to
stress the IOL 20 in order to produce a disaccommodative state in
which the eye 22 is able to focus on distant or intermediate
objects. In another example, the IOL 20 may be configured to
provide distant vision when in a natural state and an ocular force
is produced when the ciliary muscle 38 is contracted. In such
embodiments, an ocular force may be used to stress the IOL 20 in
order to produce an accommodative state in which the eye 22 is able
to focus on relatively near objects. As used herein, the terms
"natural state" or "unstressed state" of an IOL are used
interchangeably and mean a condition of an IOL in which there are
no or substantially no ocular force or other external forces on the
IOL 20, with the exception of residual forces such as gravitational
forces.
[0039] For the human eye, the ocular force is preferably in the
range of about 0.1 to 100 grams, more preferably in the range of
about 1 to 9 grams, and even more preferably in the range of about
6 to 9 grams. In certain embodiments, the ocular force produced by
the eye is in the range of about 1 to 3 grams. These preferred
ranges are based on current physiology understanding of the human
eye and are not meant to limit the scope of embodiments of the
present invention. The magnitude an ocular force available for
stressing the natural lens and/or the IOL 20 will, of course, vary
between individual subjects based, for instance, on such factors as
age of the subject, disease conditions, and the physiologic
construction of the eye. It is anticipated that as the
understanding of the physiology of the human and mammalian eye
within the field increases, the preferred range or ranges of
operation for embodiments of the present invention will be more
precisely defined.
[0040] Referring to FIGS. 1-3, in one useful embodiment of the
present invention, the IOL 20 may be used to provide accommodative
and disaccommodative vision to a subject. The IOL 20 comprises a
deformable optic 42, a rigid optic 44, and a support structure 48.
The deformable optic 42 is disposed about an optical axis 50 and
comprises a deformable surface 52 and a periphery 49. The rigid
optic 44 is disposed about the optical axis 50 and further
comprises a rigid surface 54. The deformable optic 42 also
comprises an anterior surface 60 and posterior surface 61, while
the rigid optic 44 additionally comprises an anterior surface 62
and posterior surface 63. In the illustrated embodiment, the
posterior surface 61 of the deformable optic 42 is the deformable
surface 52 and the anterior surface 62 of the rigid optic 44 is the
rigid surface 54.
[0041] The IOL 40 and the deformable optic 42 may be configured to
have a disaccommodative bias, as illustrated in FIG. 2.
Alternatively, the IOL 40 may have an accommodative bias, depending
upon various factors such as the particular physiology of eye 22
and the particular operational outcome desired by the practitioner
and/or designer. As used herein, the term "accommodative bias"
refers to an intraocular lens that is configured to provide near to
intermediate vision when in a natural or unstressed state (e.g.,
with no ocular force or other external forces on the support
structure 148). By contrast, the term "disaccommodative bias"
refers to the state of an intraocular lens wherein an optic and/or
IOL are configured to provide distant vision when in a natural or
unstressed state.
[0042] The support structure 48 is operably coupled to the
deformable optic 42, but in other embodiments may be operably
coupled to the rigid optic 44 or to both the deformable optic 42
and the rigid optic 44. In certain embodiments, the support
structure 48 is configured for pressing the deformable surface 52
of the deformable optic 42 and the rigid surface 54 of the rigid
optic 44 together in response to or in the presence of an ocular
force, wherein at least a portion of the deformable surface 52
changes shape such that the optical power of the at least a portion
of the deformable surface 52 and/or the IOL 20 changes, typically
by at least about 1 Diopter, preferably by at least 2 Diopters,
more preferably by 3 Diopters, and even more preferably by at least
4 or 5 Diopters. In certain embodiments, the support structure 48
produces a force F.sub.p that presses the deformable surface 52 and
the rigid surface 54 together in the response to an ocular force
such that at least a portion of the deformable surface 52 is
deformed and substantially conforms to the shape of the rigid
surface 54.
[0043] In other embodiments, the support structure 48 is configured
for pressing the deformable surface 52 and the rigid surface 54
together in the absence of an ocular force, wherein at least a
portion of the deformable surface 52 changes shape such that the
optical power of the at least a portion of the deformable surface
52 and/or the IOL 20 changes, typically by at least 1 or 2 Diopters
or more compared to the optical power of the IOL 20 when the
deformable surface 52 is in an undeformed state. In such
embodiments, the IOL 20 is configured to produce an internal force
or forces that press the deformable surface 52 and the rigid
surface 54 together when there are no external force, such as an
ocular force, acting of the IOL 20. The IOL is further configured
so that application of an external force, such as an ocular force,
opposes the internal force or forces produced by the IOL 20 such
that the surfaces 52, 54 are no longer pressed together or are only
partially pressed together.
[0044] Referring to FIGS. 4 and 5, the deformable optic 42 may
further comprise a relief portion 82 that is configured to provide
a volume into which material from the deformable optic 42 may flow,
enlarge or expand when the deformable surface 52 is deformed as it
is pressed against the rigid surface 54. By providing a volume into
which material may expand when the surfaces 52, 54 are pressed
together, the relief portion 82 may be used to reduce the
possibility that changes in the optical power produced by
deformation of the deformable surface 52 are opposed or cancelled
by a similar deformation in the opposite surface 60. The relief
portion may comprise at least a portion of the periphery 49 about
the deformable optic 42 that is not in contact with the support
structure 48. For example, comparing FIGS. 4 and 5, the relief
portion 82 is seen to comprise a portion of the periphery that is
posterior to the haptic 70 and anterior to the rigid surface 54 of
the rigid optic 44. The relief portion 82 is seen in FIG. 5 to
bulge and fill with material from the deformable optic 42 when the
deformable optic 42 is pressed against the rigid optic 44. In other
embodiments, the relief portion 82 may comprise voids or opening
within the body of the deformable optic 42 that also be used to
allow fluid flow between the anterior and posterior portions of the
anterior chamber 24 of the eye 22.
[0045] In certain embodiments, the deformable surface 52 is
configured to be less stiff than the opposite surface 60 of the
deformable optic 42. Similar to the relief portions 82, the greater
stiffness of the opposite surface 60 be used to reduce the
possibility that changes in the optical power produced by
deformation of the deformable surface 52 are opposed or cancelled
by a similar deformation in the opposite surface 60. The stiffness
of the opposite surface 60 may be provided by operably coupling a
stiffening coating or layer 78 to the deformable optic 42 that is
made of a material that is harder or stiffer than the material from
which other portions of the deformable optic 42 are made.
Alternatively or additionally, the stiffening layer 78 may be
integrally formed with the deformable optic 42 and/or the support
structure 48 by hardening the opposite surface 60. The hardening
may be accomplished, for example, by addition polymerization of the
stiffening layer 78 over and above the amount of polymerization
used in forming other portions of deformable optic 42. In the
illustrated embodiment of FIGS. 1-5, the stiffening layer 78 is
disposed in front of the anterior surface 60 of the deformable
optic 42. More generally, the stiffening layer 78 is preferably
disposed such that the deformable optic 42 is located between the
stiffening layer 78 and the rigid optic 44.
[0046] In certain embodiments, the IOL 20 is configured for
placement within the eye 22, for example within the sulcus 39, as
illustrated in FIGS. 1-3. Alternatively, the IOL 20 may be
configured for placement within another portion of the eye 22, for
example within the capsular bag 32. The IOL 20 may be constructed
of any of the commonly employed materials in the art, for example a
silicone polymeric material, an acrylic polymeric material, a
hydrogel-forming polymeric material, such as
polyhydroxyethylmethacrylate, polyphosphazenes, polyurethanes,
and/or mixtures thereof. Combinations of the deformable optic 42,
the rigid optic 44, and the support structure 48 may be the same
material. Alternatively, each of these elements of the IOL 20 may
be made of different materials. In certain embodiments, the entire
IOL 20 is made of substantially the same material and is integrally
formed to produce a compound structure for placement within the eye
22 as a single unit. Alternatively, one or more of the components
of IOL 20 are made separately and assembled within the eye to form
the IOL 20. Such a modular construction may advantageously allow
the use of a smaller incision in the eye 22, thereby reducing
healing time and general trauma to the eye 22.
[0047] In certain embodiments, the rigid optic 44 is disposed
against or in contact with the posterior capsule 32, and the
deformable optic 42 is disposed in front of or anterior to the
rigid optic 44. In such embodiments, the deformable optic 42 is
preferably configured to vault in a posterior direction (away from
the cornea 28) so that it may be effectively pressed against the
rigid optic 44 in response to or in the absence of an ocular force.
The total optical power of the IOL 20 may be determined from the
individual powers of the deformable optic 42 and the rigid optic 44
and may change depending on whether or not the deformable optic 42
and the rigid optic 44 are pressed together.
[0048] The optics 42, 44 may be constructed of any one or a
combination of the commonly employed materials found in the art.
For example, the rigid optic 44 may be of a relatively rigid
material such as polymethylmethacrylate (PMMA), while the
deformable optic 42 is made of one of the more resiliently
deformable material found in the art, such as a silicone polymeric,
an acrylic polymeric, a hydrogel-forting polymeric, or mixtures
thereof. The material or materials used to form the optics 42, 44
are preferably optically clear optics that exhibit biocompatibility
in the environment of the eye. The selection of suitable lens
materials is 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,
herein incorporated by reference.
[0049] In certain embodiments, the deformable optic 42 and/or the
rigid optic 44 are made of a solid material. As used herein, the
term "solid" means a material that does not primarily comprise a
gas or a liquid and/or that is a homogeneous material with the
ability to maintain a substantially fixed surface, form, or shape
in the presence of small external forces placed on an object made
of such a material. The term "solid" includes gel materials such as
hydrogel materials, hydrophilic material, and hydrophobic materials
that comprise a polymeric material containing less than 50% liquid
by weight. As used herein, the term "substantially fixed" means
that variations in the surface, form, or shape of an optic are
small in comparison to the variations necessary to induce
significant optical aberrations, that is optical aberrations that
are greater than about 10 times the diffraction limited.
[0050] Typically, the deformable optic 42 and/or the rigid optic 44
of the IOL 20 are made of foldable material to allow insertion of
the IOL 20 through an incision in the eye 22 that is less than
about 5 mm in diameter, more preferably less than about 3 mm in
diameter, and even more preferably less than about 2 mm in
diameter. As used herein, the term "foldable optic" means an optic
that is sufficiently pliable to be rolled, folded, compressed, or
otherwise deformed for insertion into an incision that is smaller
than the diameter of the optic, and is sufficiently resilient to
return to substantially its original shape and/or provide
substantially the same optical characteristic that the lens had
prior to insertion into the eye. As used herein, the term
"deformable optic" means an optic having a least one surface
configured so that at least a portion of that surface changes shape
when subjected to an ocular force or a force in the range of about
0.1 gram to about 100 grams.
[0051] As used herein, the term "rigid" refers to the ability of a
structure to resist changes in form resulting from ocular forces
thereon, for example, the ability of a lens or surface to resist
changes in the radius of curvature, the thickness, and/or the
asphericity thereof. As used herein, the terms "deformable" refer
to the ability of a structure to change form resulting from ocular
forces thereon. The terms "rigid" and "deformable" are used herein
to refer to the relative rigidity or deformability of one of the
rigid optic 44 as compared to that of the deformable optic 42.
These terms do not generally refer to the rigidity or deformability
of the optics 42, 44 in an absolute sense. Typically, both optics
42, 44 are at least somewhat deformable in the sense that they may
be resiliently bent or folded for insertion into the eye 22 so as
to reduce the amount of trauma to the eye 22 during a surgery and
the healing time after the surgery.
[0052] The rigid optic 44 may also be made of one of the more
resiliently deformable materials listed above for the deformable
optic 42, so long as the final composition or construction of the
rigid optic 44 is more rigid than that of the deformable optic 42.
For example, both the rigid optic 44 and the deformable optic 42
may be made of acrylic materials. In such embodiments, acrylic
material used to form the rigid optic 44 may be made stiffer than
that used to from the deformable optic, for example, by making the
rigid optic 44 thicker than the deformable optic 42, by increasing
the degree of polymerization of the material used to form the rigid
optic 44 relative to that of the deformable optic 42, or by forming
the rigid optic 44 from a type of acrylic material that is stiffer
than that used to form the deformable optic 42.
[0053] The materials used to form the optics 42, 44 typically have
refractive indices that allow fabrication of relatively thin and
flexible optics. Each of the optics 42, 44 may have a thickness in
the range of about 150 microns or less to about 1500 microns or
more, preferably in the range of about 150 microns to about 500
microns. In order to provide greater rigidity, the rigid optic 44
typically has a center thickness that is greater than the center
thickness of the deformable optic 42. Each of the optics 42, 44
typically has a diameter that is about 4.5 mm or less to about 6.5
mm or more, preferably from about 5.0 mm to about 6.0 mm. In
certain embodiments, the center thickness of the rigid optic 44 is
thicker than the center thickness of the deformable optic 42,
especially if both the optics 42, 44 are made of the same material
or materials having the same stiffness when formed into the same
structure or shape.
[0054] The optics 42, 44 may generally take any of the lens forms
known in the art, either prior to or after the deformable surface
52 and the rigid surface 54 are pressed together. For example,
either of the optics 42, 44 may be a biconvex lens, a biconcave
lens, a plano-convex lens, a plano-concave lens, or a meniscus
lens. The optical power of each of the optics 42, 44 may be either
positive or negative. Alternatively, the optical power of one of
the optics 42, 44 may be positive, while the optical power of the
other is negative. In certain embodiments, the general form of the
deformable optic 42 may change after the surfaces 52, 54 are
pressed together. For example, the deformable optic 42 may be a
plano-convex lens prior to pressing the surfaces 52, 54 together
and a biconvex lens after pressing the surfaces 52, 54
together.
[0055] The combined refractive optical power of the optics 42, 44
is preferably within a range of about +5 Diopters to at least about
+50 Diopters, more preferably within a range of at least about +10
Diopters to at least about +40 Diopters, and even more preferably
within a range of at least about +15 Diopters to at least about +30
Diopters. The most preferred range is that typical of IOLs used in
aphakic eyes, for instance after cataract surgery. In other
embodiments, the combined refractive optical power of the optics
42, 44 may be within a range of about +5 Diopters about -5
Diopters, or less.
[0056] In certain embodiments, the rigid optic 44 is configured to
either increases or decreases radius of curvature of the deformable
surface 52 when the surfaces 52, 54 are pressed together.
Typically, the surfaces 62, 63 of the rigid optic and/or the
surface 60 opposite the deformable surface 52 are configured to
maintain a fixed or substantially fixed shape when the surfaces 52,
54 are pressed together. The shape of any of the surfaces 60-63 of
the optics 42, 44 may either spherical or flat, either prior to or
after the deformable and rigid surfaces 52, 54 are pressed
together. Alternatively, at least one of the surfaces 60-63 of the
optics 42, 44 may be an aspheric surface or have an asymmetric
surface, either prior to or after the deformable and rigid surfaces
52, 54 are pressed together. For instance, the profile or shape of
at least one of the surfaces 60-63 may be parabolic or some other
aspheric shape for reducing an aberration such as a spherical
aberration. For example, one or more of the surfaces 60-63 may be
an aspheric surface that is configured to reduce spherical
aberrations based on either an individual cornea or group of
corneas, for example, as described by Piers et al. in U.S. Pat. No.
6,609,673 and U.S. patent application Ser. No. 10/724,852, which
are herein incorporated by reference.
[0057] In certain embodiments, at least one of the optics 42, 44
comprises a diffractive surface, either prior to or after the
deformable and rigid surfaces 52, 54 are pressed together. For
instance, at least one of the surfaces 60-63 of the optics 42, 44
may comprise a diffractive surface that is configured to correct an
aberration of the deformable optic 42, the rigid optic 44, the IOL
20, and/or the eye 22. For example, the diffractive surface may be
configured to correct a chromatic aberration, as described in U.S.
Pat. No. 6,830,332, which is herein incorporated by reference. The
diffractive surface may be configured to cover the entire or
substantially the surface of at least one of the surfaces 60-63,
either prior to or after the deformable surface 52 and the rigid
surface 54 are pressed together. Alternatively, the diffractive
surface may cover only a portion of at least one of the surfaces
60-63, for example as described in U.S. Pat. Nos. 4,881,804 and
5,699,142, which is herein incorporated by reference. In other
embodiments, a portion of one of the surface 60-63 having the
diffractive surface may be configured to provide an optical power
that is different from the optical power of a remaining portion of
the surface 60-63 that does not contain a diffractive
component.
[0058] In other embodiments, at least one of the optics 42, 44 is
able to provide more than one optical power, for example, a bifocal
or multifocal lens, either prior to or after the deformable surface
52 and the rigid surface 54 are pressed together. This may be
accomplished by varying the refractive power of one of the surfaces
60-63 as a function of radius from the optical axis 50, for
example, as described in U.S. Pat. Nos. 4,898,461 and 5,225,858,
which are herein incorporated by reference. Alternatively or
additionally, the one or more of the surfaces 60-63 may contain a
diffractive surface in which two or more diffractive orders are
used to provide two or more optical powers, for examples, as
discussed in U.S. Pat. Nos. 4,642,112 and 5,121,979, which are also
herein incorporated by reference.
[0059] In certain embodiments, at least one of the surfaces 52, 54
comprise a multifocal and/or diffractive surface that is configured
to correct an optical aberration, provide more than one focus,
and/or provide some other desired optical effect when the surfaces
52, 54 are separated (e.g., not pressed together). In such
embodiments, the correction or effect produced by the multifocal
and/or diffractive surface may be reduced or eliminated when the
surfaces 52, 54 are pressed together, either in response to or in
the absence of an optical force. In other embodiments, the rigid
surface 54 comprises a multifocal and/or diffractive surface that
is configured to correct an optical aberration, provide more than
one focus, and/or provide some other desired optical effect when
the surfaces 52, 54 are pressed together. In such embodiments, the
correction or effect produced by the multifocal and/or diffractive
surface may be reduced or eliminated when the surfaces 52, 54 are
separated from one another.
[0060] The materials and/or surface profiles of the deformable
optic 42, the rigid optic 44, and/or the stiffening layer 78 may be
advantageously selected to correct an optical aberration of the IOL
20 or the eye 22. For example, the IOL 20 may be used to correct a
chromatic aberration, wherein the deformable optic 42 is made of a
first material and the rigid optic 44 is made of a second material.
In such embodiments, the refractive index and/or Abbe number of the
first material is selected to be different from that of the second
material, while the radius of curvature of anterior and posterior
surfaces 62, 63 of the rigid optic 44 are preferably selected so
that the rigid optic 44 has either a positive or negative optical
power. Those of skill in the art are able to select the optical
powers of the optics 42, 44 and the materials thereof such that the
chromatic dispersion of one of the optics is combined with
chromatic dispersion of the other optic to provide reduced
chromatic aberrations and a combined optical power that is
substantially equal over a range of wavelengths. The two optics 42,
44 may be configured to correct a chromatic aberration or some
other optical aberration either before or after deformation of the
deformable optic 42 caused when the surfaces 52, 54 are pressed
together.
[0061] Alternatively or additionally, the stiffening layer 78 may
be made of a material having a refractive index or Abbe number that
is different from that of the deformable optic 42 and/or the rigid
optic 44 in order to correct for a chromatic aberration some other
aberration of the IOL 20 or the eye 22. In such embodiments, the
stiffening layer 78 comprises anterior and posterior surfaces 79,
80 that are preferably selected so that stiffening layer 78 has
either a positive or negative optical power. It will be appreciated
that the center thickness of the stiffening layer 78 may be
considerably greater than or considerably less than the thickness
illustrated in FIGS. 4 and 5, either in an absolute sense or
relative to the center thickness of the deformable lens 42 along
the centerline 50. In other embodiments, the optical power,
refractive index, and/or Abbe number of the stiffening layer 78,
the deformable optic 42, and the rigid optic 44 may be selected so
that the IOL 20 is able correct for a chromatic aberration or other
optical aberration when the deformable optic 42 is either in a
deformed or undeformed state.
[0062] In some embodiments, the rigid optic 44 may also be used to
protect and/or strengthen the posterior surface of the capsular bag
32. In this and other embodiments, the rigid optic 44 may be a
meniscus lens having either positive or negative optical power,
depending on the relative curvatures of the anterior and posterior
surfaces 62, 63 of the rigid optic 44. Alternatively, the rigid
optic 44 may have no optical power or substantially no optical
power. For example, in the illustrated embodiment, the rigid optic
44 forms a meniscus lens in which the radius of curvature of the
surface 62 is selected to be substantially equal to that of the
surface 63, so that rays from light entering the rigid optic 44
experiences substantially no net bending as the rays passing
through the rigid optic 44. In such embodiments, a slight amount of
bending may take place, for example, due to imperfections in or
stresses on the rigid optic 42, for example due to an ocular
force.
[0063] In certain embodiments, the support structure 28 comprises
one or more haptics 70 having a proximal end 72 that is attached to
the deformable optic 42 and distal end 74. The haptics 70 may be
formed integrally with the deformable optic 42 and/or the rigid
optic 44. Alternatively, the haptics 70 may be separately attached
to the deformable optic 42 and/or the rigid optic 44 using any of
the methods or techniques known in the art. Typically, the support
structure 48 is made of a material that is stiffer or more rigid
than either or both of the optics 42, 44, although any combination
of relative stiffness between the support structure 48 and the
deformable and/or rigid optics 42, 44 is possible.
[0064] The haptics 70 are typically fabricated from a material that
is 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-hydroxyethylmethacrylate, poly (vinylidene fluoride),
polytetrafluoroethylene and the like; and metals such as stainless
steel, platinum, titanium, tantalum, shape-memory alloys, e.g.,
nitinol, and the like. In general, the haptics 70 may comprise any
material exhibiting sufficient supporting strength and resilience
for maintaining at least one of the optics 42, 44 in the center of
the eye 22 and for moving the optics 42, 44 relative to one another
in the presence of an ocular force.
[0065] Referring to FIGS. 6 and 7, in certain embodiments, an IOL
120 comprises a deformable optic 142, a rigid optic 144, and a
support structure 148 that are disposed about an optical axis 150.
The deformable optic 142 comprises a deformable surface 152, while
the rigid optic 144 comprises a rigid surface 154. Typically, the
support structure 148 is operably coupled to the deformable optic
142 and is configured for pressing the deformable surface 152 and
the rigid surface 154 together either in response to an ocular
force or in the absence of an ocular.
[0066] The support structure 148 comprises an optic positioning
element 160 having an anterior segment 161 configured for yieldable
engagement with an anterior capsule 34, a posterior segment 162 for
yieldable engagement with a posterior capsule 36, and an equatorial
segment 163 disposed between the anterior segment 161 and the
posterior segment 162. The positioning element 160 is typically
constructed such that the equatorial segment 163 is in contact with
an equatorial portion of the capsular bag 32 as it changes shape in
response to the application or removal of an ocular force. In
addition, the optic positioning element 160 is preferably
configured to fill or to substantially fill the entire capsular bag
32, such that when an ocular force is applied or removed, a change
in the shape of the capsular bag 32 produces a change in the shape
of the optic positioning element 160 that causes the deformable
surface 152 and the rigid surface 154 to be pressed together. The
deformable optic 142 and the rigid optic 144 are configured such
that the deformable surface 152 is deformed when the optics 142,
144 are pressed together, typically by at least about 1 Diopter,
preferably by at least 2 Diopters, more preferably by 3 Diopters,
and even more preferably by at least 4 or 5 Diopters.
[0067] The support structure 148 further comprises a plurality of
arms 170 for transferring an ocular force on the optic positioning
element 160 to the deformable optic 142. In the illustrated
embodiment in FIG. 7, each of the arms 170 comprises a proximal end
172 connected to the deformable optic 142 that may be either
integrally formed therewith or formed separately and attached to
the optic 142. Each of the arms 170 further comprises distal ends
174 that may be connected to the optic positioning element 160 at
or near the equatorial segment 163 and that may be either
integrally formed optic positioning element 160 or formed
separately and attached thereto. In other embodiments, the arms 170
may be connected to some other portion of the optic positioning
element 160, for example to the posterior segment 162. These and
other configuration for attaching the arms 170 to the optic
positioning element 160 are further illustrated in U.S. patent
application Ser. Nos. 10/280,937 and 10/634,498, both of which are
herein incorporated by reference.
[0068] The rigid optic 144 is typically attached or operably
coupled to the optic positioning element 160 at an opening 175 in
the anterior segment 161 so as to prevent decentering of the rigid
optic 144 relative to the optical axis 150. The rigid optic 144 is
typically disposed within the optic positioning element 160 and
adjacent to the anterior segment 161.
[0069] The optic positioning element 160 may be configured to
comprise a front interior chamber 156 formed by the boundaries of
the rigid optic 144, the deformable optic 142, and the inner walls
of the optic positioning element 160. The optic positioning element
160 may further comprise a rear interior chamber 157 formed by
volume within the boundaries of the deformable optic 142 and the
inner walls of the optic positioning element 160.
[0070] To facilitate the fluid flow or fluid communication between
the front interior chamber 156 and the posterior chamber 26 of the
eye 22, the rigid optic 144 may comprises a plurality of through
holes or openings 176 that are typically disposed at or near the
periphery of the rigid optic 144. In certain embodiments, fluid
flow into or out of the front interior chamber 156 is additionally
or alternatively provided by offsetting the rigid optic 144
posteriorly along the optical axis 155 from the interior wall of
the anterior segment 161. One such configuration is illustrated,
for example, by FIGS. 7, 8, and 10 of U.S. patent application Ser.
No. 10/280,937. In order to facilitate fluid flow or fluid
communication between the front and rear interior chambers 156,
157, the deformable optic 142 typically comprises one or more
openings or through holes 180. Preferably, at least some of the
through holes 176 of the rigid optic 144 are aligned with or
overlap with at least some of the through holes 180 of the
deformable optic 142.
[0071] The deformable optic 142 may further comprise a stiffening
layer 178 disposed adjacent to the deformable optic 142 opposite
the deformable surface 152. When the deformable optic 142 and the
rigid optic 144 are pressed together, the stiffening layer 178 may
be used to prevent or inhibit deformation of the surface of the
deformable optic 142 that is opposite the deformable surface 152.
In certain embodiments, deformation of the surface opposite the
deformable surface 152 may be further reduced or eliminated when
the surface 152, 154 are pressed together by a relief portion 182
for providing a volume into which material from the deformable
optic 142 may flow, enlarge or expand. The relief portion 182 may
be disposed about the periphery of the deformable optic 142, for
example, as illustrated in FIGS. 4 and 5 for the deformable optic
42. Additionally or alternatively, the relief portion 182 may
comprise one or more voids or opening 184 within the body of the
deformable optic 142. The openings 184 may be the same as the
openings 176 for providing fluid communication between the rear
interior chamber 157 and the rest of the eye 22. Alternatively, at
least some of the openings 184 used for providing relief during
deformation of the deformable optic 142 may be different from at
least some of the openings 180 for providing fluid communication
between interior chambers 156, 157.
[0072] In certain embodiments, the deformable optic 142 is disposed
behind the rigid optic 144 and in close proximity therewith when
the surfaces 152, 154 are not pressed together. In certain
embodiments, there is a gap 177 along the optical axis 150 between
the deformable optic 142 and the rigid optic 144 when the surfaces
152, 154 are not pressed together. In such embodiments, the size of
the gap 177 may be selected to allow a predetermined amount of
axial travel of the deformable optic 142 before it engages the
rigid optic 144. In other embodiments, the gap 177 is substantially
zero or there is no gap 177, in which case the deformable optic 142
may touch the rigid optic 144 when the surfaces 152, 154 are not
pressed together. In such embodiments, the deformable optic 142 may
be disposed to only touches the rigid optic 144 at a point
substantially along the optical axis 150.
[0073] Referring to FIGS. 8 and 9, in certain embodiments, an IOL
20' comprises a deformable optic 42' and a support structure 48',
but does not include a rigid optic such as the rigid optic 44 of
the IOL 20. In such embodiments, the support structure 48' is
operably coupled to the deformable optic 42' for pressing a
deformable surface 52' and at least one surface of the capsular bag
32 (e.g., the anterior capsule 34 and/or the posterior capsule 36)
of the eye 22 together in response to or in the absence of an
ocular force, whereby at least a portion of the deformable surface
52' changes shape such that the optical power of the at least a
portion of the deformable surface 52' and/or the IOL 20' changes,
typically by at least about 1 Diopter, preferably by at least 2
Diopters, more preferably by 3 Diopters, and even more preferably
by at least 4 or 5 Diopters. In such embodiments, the IOL 20'
preferably also comprises a relief portion 82' for providing a
volume into which material from the deformable optic 42' may flow,
enlarge or expand when the deformable surface 52' is deformed.
[0074] Referring to FIGS. 10 and 11, in certain embodiments, an IOL
220 comprises a deformable optic 242 having a deformable surface
252 and a rigid optic 244 having a rigid surface 254, the optics
242, 244 being disposed about the optical axis 50 of the eye 22. In
such embodiments, only a portion 255 of the deformable surface 252
changes shape when the deformable surface 252 and the rigid surface
254 are pressed together in response to or in the absence of an
ocular force, whereby only a portion of light entering the IOL 220
and/or the deformable optic 242 experiences a change in optical
power. The optic 240 may further comprise a support structure 248
that is operably coupled to the deformable optic 242.
Alternatively, in other embodiments, the support structure 248 may
be operably coupled to the rigid optic 244 or to both the
deformable optic 242 and the rigid optic 244. The IOL 240 and the
deformable optic 242 may be configured to have a disaccommodative
bias, as illustrated in FIG. 10. Alternatively, the IOL 240 may
have an accommodative bias, depending upon various factors such as
the particular physiology of eye 22 and the particular operational
outcome desired by the practitioner and/or designer.
[0075] In certain embodiments, the deformable surface 252 is
concave, as illustrated in FIGS. 10 and 11, in which case the
deformable portion 255 is a peripheral portion 256 of the
deformable surface 252. In such embodiments, the deformable portion
255 has an inner diameter D.sub.inner that is less than about 5 or
6 mm, preferably less than about 4 mm. In certain embodiments, the
deformable portion 255 has an inner diameter D.sub.inner that is
less than about 3 mm. The inner diameter D.sub.inner of the
deformable portion 255 may be selected based on various factors
including the area or percentage of the IOL 220 and/or the
deformable surface 252 that is to be directed to near or
intermediate vision when the IOL 220 is in an accommodative state.
The deformable portion 255 of the IOL 220 may advantageously
provide the capability of forming a multifocal lens when the eye 22
is in an accommodative state. In other embodiments, the
configuration of the IOL 220 illustrated in FIG. 11 represents a
condition in which the eye 22 is only partially accommodated. In
such embodiments, the entire or substantially the entire deformable
surface 252 is deformed when the eye attains a fully accommodative
state.
[0076] Referring to FIG. 12, in certain embodiments, the deformable
optic 242 comprises a deformable surface 252' that is convex. In
such embodiments, the deformable portion 255 is a central portion
257 of the deformable surface 252'. In such embodiments, the
deformable portion 255 has an outer diameter D.sub.outer that is
greater than about 1 mm, preferably greater than about 2 mm. In
certain embodiments, the deformable portion 255 has an outer
diameter D.sub.outer that is greater than about 3 mm or 4 mm. The
outer diameter D.sub.outer of the deformable portion 255 may be
selected based on various factors including the area or percentage
of the IOL 220 and/or the deformable surface 252 that is to be
directed to distant or intermediate vision when the IOL 220 is in
an disaccommodative state. The IOL 242 illustrated in FIG. 12
comprises a deformable surface 252' that has a smaller radius of
curvature than that of the rigid surface 254 of the rigid optic
244. Alternatively, the deformable surface 252' may have a larger
radius of curvature than that of the rigid surface 254. The
deformable portion 255 of the IOL 220 illustrated in FIG. 12 may
advantageously provide the capability of forming a multifocal lens
when the eye 22 is in a disaccommodative state. In other
embodiments, the configuration of the IOL 220 illustrated in FIG.
12 represents a condition in which the eye 22 is only partially
accommodated. In such embodiments, the entire or substantially the
entire deformable surface 252 is deformed when the eye attains a
fully disaccommodative state.
[0077] Referring to FIG. 13, a method 300 of providing
accommodation to a subject will now be discussed using the IOL 120.
It will be appreciated that at least portions of the method 300 may
be practiced using the IOLs 20, 20', 120, 220, or other IOLs
consistent with embodiments of the present invention. The method
300 comprises an operational block 310, which comprises providing
the IOL 120. The method 300 additionally comprises an operational
block 320, which comprises placing, injecting, or implanting the
IOL 120 into the eye 22 of a subject. The method 300 further
comprises an operational block 330, which comprises allowing the
deformable surface 152 and the rigid surface 154 to be pressed
together in response to or in the absence of an ocular force. The
method also comprises an operational block 340, which comprises
allowing the shape of the deformable surface 152 to change as the
surfaces 152, 154 are pressed together such that the optical power
of the at least a portion of the deformable surface 152 and/or the
IOL 120 changes, typically by at least about 1 Diopter, preferably
by at least 2 Diopters, more preferably by 3 Diopters, and even
more preferably by at least 4 or 5 Diopters.
[0078] In certain embodiments, for example in the case of the IOL
20' illustrated in FIGS. 8 and 9, the operational block 320
comprises allowing the deformable surface 52' of the deformable
optic 20' and a surface of the capsular bag 32 (e.g., the anterior
capsule 34 and/or the posterior capsule 36) to be pressed together
in response to or in the absence of an ocular force. In such
embodiments, the operational block 330 comprises allowing the shape
of the deformable surface to change as the surfaces of the
deformable optic 42' and the capsular bag 32 are pressed together
such that the optical power of the IOL changes, typically by at
least about 1 Diopter, preferably by at least 2 Diopters, more
preferably by 3 Diopters, and even more preferably by at least 4 or
5 Diopters. In other embodiments, the operational blocks 330 and
340 together alternatively comprise configuring the support
structure 148 for pressing the deformable surface 152 and the rigid
surface 154 together in response to an ocular force, whereby at
least a portion of the deformable surface 152 changes shape such
that the optical power of the intraocular lens changes, typically
by at least about 1 Diopter, preferably by at least 2 Diopters,
more preferably by 3 Diopters, and even more preferably by at least
4 or 5 Diopters. In general other means consistent with embodiments
of the present invention may be used for pressing a deformable
surface and a rigid surface together in response to an ocular
force, for example, the support structures 48, 48', 148, or 248,
the haptics 70, the arms 170.
[0079] With additional reference to FIGS. 7, 14, and 15, in
operational block 320, the IOL 120 may be implanted within the
capsular bag 32 of the eye 22 using forceps, an inserter or
injector device, or some other device or means suitable for the
task. Once the IOL 120 is implanted into the eye 22, it may be
manipulated until suitably disposed and centered within the eye 22.
The entire IOL 120 may be implanted within the eye 22 at one time
or, alternatively, different portions of the IOL 120 may be
implanted separately and then assembled and configured within the
eye 22 as desired. For example, the support structure 148 and the
deformable optic 142 may be implanted and suitably disposed within
the eye 22, followed by the implantation of the rigid optic 144.
The optics 142, 144 may then be manipulated so that their centers
are aligned to one another and with the optical axis 50.
Preferably, the support structure 148 is configured to fill or
substantially fill the capsular bag 32 when implanted into the eye
22 such that the capsular bag 32 maintains a shape that is at least
substantially the same as the shape it had prior to removal of the
natural lens.
[0080] Portions of the support structure 148 may be attached to the
capsular bag 32, for example, through fibrosis with the inner
surfaces of the capsular bag 32 (e.g., as disclosed in U.S. Pat.
No. 6,197,059, herein incorporated by reference), through the use
of a substance such as an amphiphilic block copolymer or tissue
intermediate polymer (TIP), or using some other substance, device,
or method known within the art. Attachment of the support structure
148 to the capsular bag 32 allows the shape of the support
structure 148 to conform to the capsular bag 32 as the capsular bag
32 changes shape in response to forces produced by the ciliary
muscle 38 during accommodation. Typically, the shape of the support
structure 148 in an unstressed condition is substantially the same
as that of the capsular bag 32 when the eye 22 is in either an
accommodative state or a disaccommodative state, depending on
whether the IOL 120 is configured with an accommodative bias or
disaccommodative bias, respectively.
[0081] In certain embodiments, the state of accommodation must be
controlled and maintained during a period of time in which the
support structure 148 is attaching or being attached to the
capsular bag 32. This period of time may during the surgical
procedure in which the IOL 120 is implanted into the eye 22 and/or
during a postoperative period that may last from several minutes or
hour to as much as several weeks or months. During this period of
time, the state of accommodation of the eye 22 may be controlled
using any of the various method known within the art (e.g., U.S.
Pat. Nos. 6,197,059, 6,164,282, 6,598,606 and U.S. patent
application Ser. No. 11/180,753, all of which are herein
incorporated by reference).
[0082] Operational blocks 330 and 340 of the method 300 may
comprise allowing the surfaces 152, 154 to be pressed together in
the response to or in the absence of an ocular force and allowing
the shape of the deformable surface 152 to thereby change. As
illustrated in FIG. 14, when the ciliary muscle 38 is relaxed or
retracted, the capsular bag 32 has a more discoid shape that is
substantially the same as the external form or shape of the support
structure 148 and the IOL 120 illustrated in FIG. 7. Thus, in this
embodiment, the IOL 120 has a disaccommodative bias, since the IOL
120 is in a natural or unstressed state when the eye 22 is in a
disaccommodative state. Since the radius of curvature of the
deformable surface 152 in FIG. 14 is relatively large, the focal
length of the deformable optic 142 and the IOL 120 is relatively
long, which corresponds to an eye in the disaccommodative state and
is appropriate for providing distant vision.
[0083] Referring to FIG. 15, the ciliary muscle 38 is contracted,
which causes the capsular bag 32 and the IOL 120 have a more
spheroid shape. This change in the shape of the IOL 120 causes the
deformable surface 152 of the deformable optic 142 to press against
the rigid surface 154 of the rigid optic 144. Advantageously, this
pushing together of the deformable and rigid optics 142, 144 cause
the radius of curvature of the deformable surface to decrease,
which causes the focal length of deformable optic 142 and the IOL
120 to be decreased. This decrease in focal length provides a
subject into which the IOL 120 has been implanted the ability to
see objects that are relatively closer (e.g., with near or
intermediate vision). In addition to decreasing the focal length of
the deformable optic 142, the change in shape of the support
structure 148 during contraction of the ciliary muscle 38 may also
favorably cause the deformable and/or rigid optics 142, 144 to
traverse or vault anteriorly along the optical axis 50. This
movement of the deformable and/or rigid optics 142, 144 is also
beneficial in allowing the subject to see objects that are
relatively closer. In some embodiments, this axial travel of at
least one of the optics 142, 144 of the IOL 120 may be favorably
utilized in combination with deformation of the deformable optic
142 to increase the overall add power of the IOL, thereby increase
the accommodative range and/or image quality of the IOL 120
compared to prior art accommodative IOLs.
[0084] In certain embodiments, the IOL 120 has an accommodative
bias rather than the accommodative bias construction shown in FIG.
7. For example, the IOL 120 may be configured to have the shape or
state shown in FIG. 15 when there are no or substantially no
external forces acting on the support structure 148. In such
embodiments, the eye 22 may be maintained in an accommodative state
while the support structure 148 attaches or is attached to the
walls of the capsular bag 32. Thus, during accommodation, when the
ciliary muscle 38 is contracted, the IOL 120 is in its natural or
unstressed state in which deformable surface 152 is pressed against
the rigid surface 154 of the rigid optic 144. By contrast, when the
ciliary muscle is retracted or relaxed, tension on the zonules 37
is reduced, allowing the capsular bag 32 to have the more discoid
shape shown in FIG. 14. The discoid shape of the capsular bag 32
produces an ocular force on the IOL 120 that changes the shape of
the support structure 148, which causes the deformable surface 152
(and deformable optic 142) to retract or pull away from the rigid
surface 154 (and the rigid surface 144). Since the deformable
surface 152 is no longer pressed against the rigid optic 144 under
these conditions, the deformable surface 152 returns to its
original shape and radius of curvature increases, as illustrated in
FIG. 14. The increase in the radius of curvature cause the focal
length of the deformable optic 142 and the IOL 120 to decrease.
This condition of the IOL 120 and the eye 22 may also move the
deformable and/or the rigid optics 142, 144 posteriorly along the
optical axis 50. Both these effects, the decreased focal length of
the deformable optic 142 and the posterior axial movement of the
deformable and/or rigid optics 142, 144, may be used to produce a
disaccommodative condition or provide distant vision in which a
subject is better able to focus on more distant objects.
[0085] In yet other embodiments, the IOL 120 has neither an
accommodative nor a disaccommodative bias. For example, the IOL 120
may be configured to provide intermediate vision that allows a
subject to focus on objects located at some intermediate distance.
In such embodiments, the eye 22 may be maintained in an
intermediate state between near and distant vision as the support
structure is attached or attaches to the capsular bag 32.
[0086] The IOL 120 may be configured to produce one or more of a
variety of changes in the deformable optic 142 and/or the
deformable surface 152 when the surfaces 152, 154 are pressed
together. For example, as discussed above, the radius of curvature
of the deformable surface 152 may be changed as the surfaces 152,
154 are pressed together. The change in the radius of curvature may
be used to produce a change the optical power of the IOL 120 that
is positive (a positive add power), for instance when the IOL 120
is configured to have a disaccommodative bias. Alternatively, the
change in the radius of curvature may be used to produce a change
the optical power of the IOL 120 that is negative, for instance
when the IOL 120 is configured to have an accommodative bias.
Typically, the change in optical power of the IOL 120 is at least
about 1 or 2 Diopters or more.
[0087] In certain embodiments, the change in optical power is not
simply a positive or negative change. For instance, the support
structure 148 may be used to convert the deformable optic 142 from
a single focus optic to a multifocal lens comprising refractive
and/or diffractive features to produce a plurality of focal lengths
or images. For example, the deformable surface 152 of the
deformable optic 142 may be fabricated with a spherical surface
profile, while the rigid optic 144 may be configured in the form of
a meniscus lens in which both anterior and posterior surfaces have
a multifocal type profile that is substantially the same. Since
both surfaces of the rigid optic 144 are substantially the same, it
would have little or no optical power in and of itself. However, as
the surfaces 152, 154 are pressed together, the shape of the
deformable surface 152 would conform to multifocal profile of the
rigid surface 154 and thus change from an optic producing a single
focus or image to one producing a plurality of foci or images.
[0088] In other embodiments, the deformable optic 142 has a center
thickness t.sub.i along the optical axis when in a substantially
unstressed state and a center thickness t.sub.f in the response to
or in the absence of an ocular force, wherein the surfaces 152, 154
of the deformable optic 142 and the rigid optic 144 are pressed
together. In such embodiments, the deformable optic 142 may be
adapted to change the center thickness by a factor of at least 1.1
(e.g., the quotient t.sub.f/t.sub.i is at least 1.1), typically
when the ocular force is in the range of about 1 to 9 grams,
preferably in the range of about 6 to 9 grams. In other
embodiments, the deformable optic 142 is adapted to change the
center thickness by a factor of at least 1.05 or at least 1.2 or
more. In yet other embodiments, the deformable optic 142 is adapted
to change the center thickness by a factor of at least 1.05, 1.1,
or 1.2 when the ocular force is in the range of about 1 to 3 gram.
In still other embodiments, the deformable optic 142 has a center
thickness along the optical axis when the deformable optic 142 is
in a substantially unstressed state, the deformable optic adapted
to change the center thickness by at least about 50 micrometers,
preferably at least 100 micrometers, when the ocular force is in
the range of about 1 to 9 grams, in the range of about 6 to 9
grams, or in the range of about 1 to 3 grams. Within the art, an
understanding of the physiology of the eye is still developing.
Thus, other ranges of ocular forces able to provide the above
ranges of relative and/or absolute thickness change are anticipated
as the physiology of the eye is better understood. Such ranges of
ocular forces are also consistent with embodiments of the present
invention as disclosed herein.
[0089] In certain embodiments, the method 300 further comprises
allowing correction of an optical aberration of the deformable
optic 142 and/or the eye 22 either in response to or in the absence
of an ocular force. For example, the deformable surface 152 may be
allowed to change from a substantially spherical surface when the
eye 22 is in an unaccommodated state to an aspheric surface as the
surfaces 152, 154 are pressed together. This may be accomplished by
fabricating the rigid surface 154 with an aspheric profile that
changes the deformable surface 152 as the surfaces 152, 154 are
pressed together. The change in the deformable surface 152 may be
used to reduce or eliminate one or more optical aberrations of the
deformable surface 152, the deformable optic 142, the IOL 20, and
or the entire eye 22. In other embodiments, the deformable surface
152 is fabricated with an aspheric profile that reduces aberrations
when the IOL 120 is in a first state (e.g., an accommodative or
disaccommodative state) and is deformed when the surfaces 152, 154
are pressed together to have a different aspheric profile that
reduces aberrations when the IOL 120 is in a second state that is
different from the first state.
[0090] The IOL 120 shown in FIGS. 7, 14, and 15 is configured to
have an anterior vault when the surfaces 152, 154 of the deformable
and rigid optics 142, 144 are pressed together. In other
embodiments, the method 300 may be used wherein an IOL according to
embodiments of the invention produces a posterior vault when the
deformable and rigid surfaces are pressed together.
[0091] For example, referring again to FIGS. 2 and 3, the IOL 20 is
configured to have a posterior vault, since contraction of the
ciliary muscle 38 causes the deformable optic 42 to move in the
posterior direction along the optical axis 50. Referring to the
operational block 320, the IOL 20 may be implanted into the eye 22
such that at least a portion of the support structure 28 is
configured for placement in the sulcus 39, allowing the IOL 20 to
respond directly to contractions of the ciliary muscle 38. As
illustrated in FIG. 1, the distal ends 74 of the haptics 70 may be
operably coupled to sulcus 39 such that they are substantially
fixed within the sulcus 39 as the ciliary muscle contract and
retracts. The distal ends 74 may be attached to the eye 22 through
fibrosis, through the use of a substance such as an amphiphilic
block copolymer, or through some other means known in the art.
Typically, the remaining portions of the haptics 70 are relatively
free to move in response to ocular forces and are used to change
the shape, radius of curvature, and/or thickness of the deformable
optic 42 as the optics 42, 44 are pressed together.
[0092] Referring to the operational blocks 330 and 340, the use of
the IOL 20 in providing accommodation may be demonstrated using
FIGS. 2 and 3. FIG. 2 illustrates the IOL 20 in its natural or
unstressed state in which the posterior surface 61 of the
deformable optic 42 has a relatively short radius of curvature and,
consequently, a relatively short focal length and a relatively high
optical power. This configuration of the IOL 20 corresponds to an
accommodative state of the eye 20 in which the ciliary muscle 38 is
contracted. The deformable optic 42 in this accommodative state is
preferable either proximal to the rigid optic 44 or lightly
contacts the rigid optic 44 at or near the optical axis 50.
[0093] By contrast, FIG. 3 illustrates the form of IOL 20 when the
eye 22 is in a disaccommodative state that is produced when the
ciliary muscle 38 is retracted. In this disaccommodative state, the
ocular force on the IOL 20 pushes the rigid optic 44 toward the
deformable optic 42. This causes the radius of curvature of the
deformable optic 42 to increase and become the same, as or at least
closer to, the radius of curvature of the rigid surface 54 of the
rigid optic 44. This increase in the radius of curvature causes the
IOL 20 to have a relatively large radius of curvature, so that the
IOL 20 has the relatively low optical power desirable to produce a
disaccommodative state. In addition, the deformable optic 42 and/or
the rigid optic 44 may move anteriorly along the optic axis 50 as
the eye 22 changes from the accommodative state illustrated in FIG.
2 to the disaccommodative state illustrated in FIG. 3. This axial
movement of the deformable and rigid optics 42, 44 may
advantageously allow the IOL 20 to provide a greater accommodative
range than is available using other prior art accommodative lenses
that do not utilize both optic shape change and axial travel.
[0094] The above presents a description of the best mode
contemplated of carrying out the present invention, and of the
manner and process of making and using it, in such full, clear,
concise, and exact terms as to enable any person skilled in the art
to which it pertains to make and use this invention. This invention
is, however, susceptible to modifications and alternate
constructions from that discussed above which are fully equivalent.
Consequently, it is not the intention to limit this invention to
the particular embodiments disclosed. On the contrary, the
intention is to cover modifications and alternate constructions
coming within the spirit and scope of the invention as generally
expressed by the following claims, which particularly point out and
distinctly claim the subject matter of the invention.
* * * * *