U.S. patent application number 11/252369 was filed with the patent office on 2006-05-04 for scleral expansion device having duck bill.
This patent application is currently assigned to RAS HOLDING CORP. Invention is credited to Ronald A. Schachar, Gene W. Zdenek.
Application Number | 20060095126 11/252369 |
Document ID | / |
Family ID | 27490181 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060095126 |
Kind Code |
A1 |
Zdenek; Gene W. ; et
al. |
May 4, 2006 |
Scleral expansion device having duck bill
Abstract
A prosthesis for scleral expansion includes a central body
portion and at least one end portion having a width greater than
the width of the central body portion. The end portion therefore
inhibits rotation of the prosthesis about a long axis when the
prosthesis is implanted within a scleral pocket or tunnel. The
other end of the central body portion may have a blunted end
portion including grooves for receiving a edge or lip of an
incision forming the scleral tunnel to inhibit the prosthesis from
sliding within the scleral tunnel. Curvature of the bottom surface
of the central body portion may be greater than the curvature of
the innermost surface of the scleral tunnel so that contact between
is the scleral and the bottom surface of the prosthesis is
primarily with the end portions.
Inventors: |
Zdenek; Gene W.; (West
Hills, CA) ; Schachar; Ronald A.; (Dallas,
TX) |
Correspondence
Address: |
DOCKET CLERK
P.O. DRAWER 800889
DALLAS
TX
75380
US
|
Assignee: |
RAS HOLDING CORP
Dallas
TX
|
Family ID: |
27490181 |
Appl. No.: |
11/252369 |
Filed: |
October 17, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09863006 |
May 22, 2001 |
6991650 |
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11252369 |
Oct 17, 2005 |
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09061168 |
Apr 16, 1998 |
6280468 |
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09863006 |
May 22, 2001 |
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08946975 |
Oct 8, 1997 |
6007578 |
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09061168 |
Apr 16, 1998 |
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09472535 |
Dec 27, 1999 |
6299640 |
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09863006 |
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08946975 |
Oct 8, 1997 |
6007578 |
|
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09472535 |
Dec 27, 1999 |
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09589626 |
Jun 7, 2000 |
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09863006 |
|
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08946975 |
Oct 8, 1997 |
6007578 |
|
|
09589626 |
Jun 7, 2000 |
|
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|
09061168 |
Apr 16, 1998 |
6280468 |
|
|
09589626 |
Jun 7, 2000 |
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09472535 |
Dec 27, 1999 |
6299640 |
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09589626 |
Jun 7, 2000 |
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60206134 |
May 22, 2000 |
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Current U.S.
Class: |
623/4.1 |
Current CPC
Class: |
A61F 9/0017 20130101;
A61F 2/147 20130101; A61F 2/14 20130101; A61F 9/007 20130101; A61F
9/013 20130101; A61F 9/00781 20130101 |
Class at
Publication: |
623/004.1 |
International
Class: |
A61F 2/14 20060101
A61F002/14 |
Claims
1. (canceled)
2. A scleral prosthesis, comprising: a central body portion; and an
end portion extending from the central body portion, the end
portion having a width greater than a width of the central body
portion, wherein the prosthesis is adapted so that, when the
prosthesis is inserted within a scleral pocket or tunnel in a
sclera of an eye, at least part of the end portion rests on a
portion of the sclera outside the scleral pocket or tunnel, and the
end portion also inhibits rotation of the prosthesis within the
scleral pocket or tunnel.
3. The scleral prosthesis of claim 2, wherein the prosthesis
expands a portion of the sclera proximate to the scleral pocket or
tunnel when the prosthesis is inserted within the scleral pocket or
tunnel.
4. The scleral prosthesis of claim 2, wherein the end portion is
both wider and flatter than any part of the central body
portion.
5. The scleral prosthesis of claim 2, wherein the end portion
comprises a first end portion, the prosthesis further comprising: a
second end portion extending from the central body portion, the
second end portion having a width greater than the width of the
central body portion.
6. The scleral prosthesis of claim 5, wherein at least one of: the
width of the second end portion is smaller than the width of the
first end portion; and a thickness of the second end portion is
smaller than a thickness of the first end portion.
7. The scleral prosthesis of claim 2, wherein the end portion
comprises a first end portion, the prosthesis further comprising: a
second end portion extending from the central body portion, the
second end portion comprising a blunted end portion having a width
that is not greater than the width of the central body portion.
8. The scleral prosthesis of claim 7, wherein the second end
portion comprises one or more grooves receiving a lip of the
scleral pocket or tunnel when the prosthesis is inserted within the
scleral pocket or tunnel.
9. The scleral prosthesis of claim 7, wherein the second end
portion has a thickness that tapers from a thickness of the central
body portion where the second end portion meets the central body
portion to an ending thickness that is greater than a thickness of
the first end portion.
10. The scleral prosthesis of claim 2, wherein the end portion
comprises a first end portion, the prosthesis further comprising: a
second end portion extending from the central body portion, wherein
at least one of: a cross-sectional circumference of the second end
portion is equal to or less than a cross-sectional circumference of
the central body portion; and a cross-sectional area of the second
end portion is equal to or less than a cross-sectional area of the
central body portion.
11. The scleral prosthesis of claim 2, wherein the central body
portion is circumferential.
12. The scleral prosthesis of claim 2, wherein the central body
portion is narrower in a middle of the central body portion and
wider where the end portion meets the central body portion.
13. The scleral prosthesis of claim 2, wherein the end portion is
angled with respect to the central body portion.
14. The scleral prosthesis of claim 2, wherein only part of the end
portion is capable of resting on the portion of the sclera outside
the scleral pocket or tunnel, and wherein another part of the end
portion is capable of being inserted within the scleral pocket or
tunnel.
15. A vision alteration structure including a plurality of scleral
prostheses according to claim 2 for insertion into each of a
corresponding plurality of pockets or tunnels within a sclera of an
eye.
16. A scleral prosthesis, comprising: a central body portion; a
first end portion extending from the central body portion; and a
second end portion extending from the central body portion, at
least one of the first and second end portions having one or more
grooves thereon, wherein the prosthesis is adapted so that, when
the prosthesis is inserted within a scleral pocket or tunnel in a
sclera of an eye, at least part of one or both of the first and
second end portion rests on a portion of the sclera outside the
scleral pocket or tunnel, and the one or more grooves each receive
a lip of the scleral pocket or tunnel.
17. The vision alteration structure of claim 16, wherein the one or
more grooves comprises a first groove extending across a width of
the first end portion.
18. The vision alteration structure of claim 17, wherein the one or
more grooves further comprises a second groove extending across a
width of the second end portion.
19. A scleral prosthesis, comprising: a central body portion; a
first end portion extending from the central body portion, the
first end portion having a width greater than a width of the
central body portion; and a second end portion extending from the
central body portion, the second end portion having a width greater
than the width of the central body portion, wherein the prosthesis
is adapted so that, when the prosthesis is inserted within a
scleral pocket or tunnel in a sclera of an eye, at least part of
the first and second end portions each rests on portions of the
sclera outside the scleral pocket or tunnel, and the first and
second end portions inhibit rotation of the prosthesis within the
scleral pocket or tunnel.
20. The scleral prosthesis of claim 19, wherein at least one of:
the width of the second end portion is smaller than the width of
the first end portion; and a thickness of the second end portion is
smaller than a thickness of the first end portion.
21. The scleral prosthesis of claim 19, wherein at least one of: a
cross-sectional circumference of the second end portion is equal to
or less than a cross-sectional circumference of the central body
portion; and a cross-sectional area of the second end portion is
equal to or less than a cross-sectional area of the central body
portion.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. .sctn.
119(e) (1) to U.S. Provisional Patent Application No. 60/206,134
filed May 22, 2000, and is a continuation-in-part of: (1) U.S.
Patent Application Ser. No. 09/061,168, entitled "SCLERAL
PROSTHESIS FOR TREATMENT OF PRESBYOPIA AND OTHER EYE DISORDERS" and
filed on Apr. 16, 1998, which application is a continuation-in-part
of U.S. patent application Ser. No. 08/946,975 entitled "SCLERAL
PROSTHESIS FOR TREATMENT OF PRESBYOPIA AND OTHER EYE DISORDERS" and
filed Oct. 8, 1997, now U.S. Pat. No. 6,007,578 issued Dec. 28,
1999; (2) U.S. patent application Ser. No. 09/472,535 entitled
"SCLERAL PROSTHESIS FOR TREATMENT OF PRESBYOPIA AND OTHER EYE
DISORDERS" and filed Dec. 27, 1999, which application is a
continuation of U.S. patent application Ser. No. 08/946,975; (3)
U.S. patent application Ser. No. 09/589,626 entitled "IMPROVED
SCLERAL PROSTHESIS FOR TREATMENT OF PRESBYOPIA AND OTHER EYE
DISORDERS" and filed Jun. 7, 2000, which application is a
continuation-in-part of U.S. patent applications Ser. Nos.
08/946,975, 09/061,168 and 09/472,535. All of the above-identified
documents, and the inventions disclosed therein, are incorporated
herein by reference for all purposes as if fully set forth
herein.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention relates to methods of treating presbyopia,
hyperopia, primary open angle glaucoma and ocular hypertension and
more particularly to methods of treating these diseases by
increasing the effective working distance of the ciliary muscle.
The invention also relates to increasing the amplitude of
accommodation of the eye by increasing the effective working range
of the ciliary muscle.
BACKGROUND OF THE INVENTION
[0003] In order for the human eye to have clear vision of objects
at different distances, the effective focal length of the eye must
be adjusted to focus the image of the object as sharply as possible
on the retina. Changing the effective focal length is known as
accommodation, and is accomplished in the eye by varying the shape
of the crystalline lens. Generally the curvature of the lens in an
unaccommodated emmetropic eye allows distant objects to be sharply
imaged on the retina, while near objects are not focused sharply on
the retina in the unaccommodated eye because the image lie behind
the retinal surface. In order to perceive a near object clearly,
the curvature of the crystalline lens is increased, thereby
increasing the refractive power of the lens and causing the image
of the near object to fall on the retina.
[0004] The change in shape of the crystalline lens is accomplished
by the action of certain muscles and structures within the eyeball
or globe of the eye. As described in greater detail in, for
example, U.S. Pat. No. 6,146,366, the lens has the shape of a
classical biconvex optical lens--that is, generally circular with
two convex refracting surfaces--and is located in the forward part
of the eye immediately behind the pupil and generally on the
optical axis of the eye (i.e., a straight line drawn from the
center of the cornea to the macula in the retina at the posterior
portion of the globe). In the unaccommodated human eye the
curvature of the posterior surface of the lens (the surface
adjacent to the vitreous body) is somewhat greater than that of the
anterior surface.
[0005] The lens is closely surrounded by a membranous capsule that
serves as an intermediate structure in the support and actuation of
the lens. The lens and the capsule are suspended on the optical
axis behind the pupil by a circular assembly of many radially
directed elastic fibers, the zonules, which are attached at inner
ends to the lens capsule and at outer ends to the ciliary muscle, a
muscular ring of tissue located just within the outer supporting
structure of the eye, the sclera. The ciliary muscle is relaxed in
the unaccommodated eye and therefore assumes a maximum diameter.
According to the classical theory of accommodation, originating
with Helmholtz, the relatively large diameter of the ciliary muscle
in this condition causes a tension on the zonules, which in turn
pull radially outward on the lens capsule and cause the equatorial
diameter of the lens to increase slightly, while decreasing the
anterior-posterior dimension (thickness) of the lens at the optical
axis. Thus, the tension on the lens capsule causes the lens to
assume a flattened state wherein the curvature of the anterior
surface, and to some extent the posterior surface, is less than the
curvature which would exist in the absence of the tension. In this
state the refractive power of the lens is relatively low and the
eye is focused for clear vision for distant objects.
[0006] To focus the eye on a near object, the ciliary muscles
contract. According to the classical theory, this contraction
causes the ciliary muscle to move forward and inward, thereby
relaxing the outward pull of the zonules on the equator of the lens
capsule. Such reduced zonular tension allows the elastic capsule of
the lens to contract, causing an increase in the antero-posterior
diameter (thickness) of the lens (i.e., the lens becomes more
spherical) and resulting in an increase in the optical power of the
lens. Because of topographical differences in the thickness of the
lens capsule, the central anterior radius of curvature decreases
more than the central posterior radius of curvature. This
constitutes the accommodated condition of the eye, wherein the
image of near objects falls sharply on the retina.
[0007] Presbyopia is the universal decrease in the amplitude of
accommodation that is typically observed in individuals over
40-years of age. In the person having normal vision (i.e., having
emmetropic eyes) the ability to focus on near objects is gradually
lost, and the individual comes to need glasses for tasks requiring
near vision, such as reading.
[0008] According to the conventional view the amplitude of
accommodation of the aging eye is decreased because of the loss of
elasticity of the lens capsule and/or sclerosis of the lens with
age. Consequently, even though the radial tension on the zonules is
relaxed by contraction of the ciliary muscles, the lens does not
assume a greater Curvature. According to the conventional view,
treatment to restore the accommodative power to the presbyopic eye
is not possible. The loss of elasticity of the lens and capsule is
seen as irreversible, and the only solution to the problems
presented by presbyopia is to use corrective lenses for close work,
or bifocal lenses, if corrective lenses are also required for
distant vision.
[0009] In contrast to the conventional (Helmholtz) theory, the
Schachar theory of accommodation--on which the related patent
applications identified above are based--postulates that outward
equatorial displacement of the crystalline lens produces a central
steepening (and peripheral flattening) of the lens surface. The
equatorial displacement results from increased tension on the
equatorial zonules which is produced, in turn, by contraction of
the anterior radial muscle fibers of the ciliary muscle. Since
active force is involved in accommodation, the amount of force
which may be applied to the lens equator is dependent on how much
the ciliary muscle is stretched. Since the crystalline lens is of
ectodermal origin and continues to grow throughout the life of an
individual while the dimensions of the scleral shell do not change
significantly after 13 years of age (with certain exceptions), the
distance between the ciliary muscle and the equator of the lens
decreases throughout the life of an individual. Therefore, the
effective force which the ciliary muscle may apply to the lens
equator is reduced with age, such that the decrease in the
amplitude of accommodation resulting in presbyopia is a consequence
of normal lens growth.
[0010] Such continued lens growth decreases the working distance of
the zonules and ciliary muscle, decreasing the range of
accommodation which may be achieved by contracting the ciliary
muscle to a point where focusing near objects on the retina is no
longer possible. Under this view, presbyopia may be suitably
treated by increasing the effective working distance of the ciliary
muscle, such as by increasing the distance between the ciliary
muscle and the lens equator, preferably by increasing the diameter
of the sclera (i.e., scleral expansion) in the region of the
ciliary body.
[0011] Prostheses have been disclosed in the related applications
identified above for treating presbyopia by implantation within a
number of elongated pockets formed in the sclera of the eye
transverse to a meridian of the eye, expanding the sclera and
restoring the effective working distance of the ciliary muscle.
However, as disclosed in Ser. No. 09/589,626 ("the '626
application"), such prostheses may exhibit a tendency to slide back
and forth within the scleral pocket or to turn or topple over
within the scleral pocket, reducing the effectiveness of the
prostheses in treating presbyopia in either case. In particular,
prosthesis embodiments which have a circumferential shape including
a curved bottom surface may have limited surface contact between
the bottom surface and the inner wall of the surgically formed
scleral pocket, generally in the area of the first and second ends
of the prosthesis, and therefore suffer stability problems due at
least in part, to the disproportionate surface contact of the top
surface of the prosthesis relative to the bottom surface.
[0012] There is, therefore, a need as disclosed in the '626
application to improve the stability of a prosthesis inserted
within a scleral pocket for treatment of presbyopia and other eye
disorders.
SUMMARY OF THE INVENTION
[0013] A prosthesis for scleral expansion includes a central body
portion and at least one end portion having a width greater than
the width of the central body portion. The end portion therefore
inhibits rotation of the prosthesis about a long axis when the
prosthesis is implanted within a scleral pocket or tunnel. The
other end of the central body portion may have a blunted end
portion including grooves, for receiving a edge or lip of an
incision forming the scleral tunnel to inhibit the prosthesis from
sliding within the scleral tunnel. Curvature of the bottom surface
of the central body portion may be greater than the curvature of
the innermost surface of the scleral tunnel so that contact between
the scleral and the bottom surface of the prosthesis is primarily
with the end portions.
[0014] The foregoing has outlined rather broadly the features and
technical advantages of the present invention so that those skilled
in the art may better understand the detailed description of the
invention that follows. Additional features and advantages of the
invention will be described hereinafter that form the subject of
the claims of the invention. Those skilled, in the art should
appreciate that they may readily use the conception and the
specific embodiment disclosed as a basis for modifying or designing
other structures for carrying out the same purposes of the present
invention. Those skilled in the art should also realize that such
equivalent constructions do not depart from the spirit and scope of
the invention in its broadest form.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] An advantageous embodiment of the present invention may be
understood with reference to the following descriptions taken in
conjunction with the accompanying drawings, wherein like numbers
designate like objects, in which:
[0016] FIGS. 1A and 1B are a top plan view and a side elevation
view, respectively, of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral tunnels according to one embodiment of
the present invention;
[0017] FIGS. 1C and 1D are a top plan view and a side elevation
view, respectively, of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral tunnels according to another embodiment
of the present invention;
[0018] FIGS. 1E and 1F are a top plan view and a side elevation
view, respectively, of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral pockets or tunnels according to another
embodiment of the present invention;
[0019] FIG. 1G is a top plan view of a prosthesis for increasing
the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention;
[0020] FIG. 1H is a top plan view of a prosthesis for increasing
the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention;
[0021] FIG. 1I is a side elevation view of a prosthesis for
increasing the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention;
[0022] FIG. 1J is a side elevation view of a prosthesis for
increasing the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention;
[0023] FIGS. 2A and 2B are longitudinal cross-sectional views of
the central body portion of a prosthesis for increasing the
effective working distance of the ciliary muscle by implantation
into surgically formed scleral pockets or tunnels according to
various alternative embodiments of the present invention;
[0024] FIGS. 3A through 3E are transverse cross-sectional views of
the central body portion of a prosthesis for increasing the
effective working distance of the ciliary muscle by implantation
into surgically formed scleral pockets or tunnels according to
various alternative embodiments of the present invention;
[0025] FIGS. 4A through 4D are transverse cross-sectional views of
duck bill end portions of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral pockets or tunnels according to various
alternative embodiments of the present invention;
[0026] FIGS. 5A and 5B are longitudinal cross-sections of duck bill
end portions of a prosthesis for increasing the effective working
distance of the ciliary muscle by implantation into surgically
formed scleral pockets or tunnels according to various alternative
embodiments of the present invention; and
[0027] FIG. 6 is a longitudinal cross-section of a blunted end
portion of a prosthesis for increasing the effective working
distance of the ciliary muscle by implantation into surgically
formed scleral pockets or tunnels according to one embodiment of
the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] According to present invention, presbyopia and certain other
eye disorders (e.g., hyperopia, primary open angle glaucoma, ocular
hypertension, etc.) may suitably be treated by increasing the
effective working distance of the ciliary muscle. Such increase may
be achieved by increasing the distance between the ciliary muscle
and the lens equator, preferably by increasing the diameter of the
sclera (i.e., scleral expansion) in the region of the ciliary body.
According to one embodiment of the present invention, the effective
working distance of the ciliary muscle may suitably be increased by
implanting, within pockets surgically formed in the sclera of the
eye, a plurality of prostheses designed to place an outward
traction on the sclera in the region of the ciliary body.
[0029] FIGS. 1A and 1B are a top plan view and a side elevation
view, respectively, of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral tunnels according to one embodiment of
the present invention. Prosthesis 100 includes a central body
portion 101 connecting end portions 102 and 103. As with the
prostheses described in the related applications described above,
prosthesis 100 is intended to be inserted within a surgically
formed pocket or tunnel within the sclera, elevating a portion of
the sclera to increase the effective working distance of the
ciliary muscle.
[0030] The planform of exemplary prosthesis 100 of FIGS. 1A-1B
includes "duck bill" end portions 102 and 103 which are wider and
flatter (and, in the exemplary embodiment, thinner) than the
intermediate central body portion 101. These "duck bill" end
portions promote stability when the prosthesis 100 is within the
scleral tunnel, inhibiting the prosthesis 100 from turning or
toppling over (i.e., rotating about a long axis of the prosthesis
100) within the scleral tunnel.
[0031] When prosthesis 100 is inserted within a scleral tunnel,
essentially all of central body portion 101 is preferably contained
within the tunnel, while essentially all of end portions 102 and
103 are preferably outside the scleral tunnel (i.e., the scleral
tunnel has a length approximately equal to the length of central
body portion 101 of prosthesis 100). In such instances, central
body portion 101 is within the sclera or under the scleral layer,
while end portions 102 and 103 are on the sclera, a bottom surface
of end portions 102 and 103 in contact with an outer surface of the
sclera. Alternatively, however, one or more portions of central
body portions 101 proximate to end portions 102 and/or 103 may be
outside the scleral tunnel, or one or more portions of end portions
102 and/or 103 may be within the tunnel (i.e., the scleral tunnel
has a length which is either greater than or less than the length
of central body portion 101 of prosthesis 100).
[0032] FIGS. 1C and 1D are a top plan view and a side elevation
view, respectively, of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral tunnels according to another embodiment
of the present invention. In the embodiment of FIGS. 1C-1D, one
duck bill end portion 102 projecting from the central body portion
101 of the prosthesis 110 is wider and/or thicker than the other
duck bill end portion 104. During insertion of the prosthesis 110
within a scleral tunnel, narrower and/or thinner end portion 104 is
intended to be passed through both incisions within the sclera
which form the ends of the scleral tunnel. The benefits of having
one duck billed end portion 104 which is narrower and/or thinner
than the other is addressed in further detail below.
[0033] FIGS. 1E and 1F are a top plan view and a side elevation
view, respectively, of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral pockets or tunnels according to another
embodiment of the present invention. Prosthesis 120 in the
embodiment of FIGS. 1E-1F includes only duck billed end portion 102
projecting from the central body portion 101. The other end of the
central body portion may have no end portion, or, as shown in the
example of FIGS. 1E-1F, may have an end portion 105 which is not
wider than central body portion 101. In the example shown, blunted
end portion 105 is not as long as duck bill end portion 102.
However, blunted end portion 105 is substantially thicker than duck
bill end portion 102, tapering from the thickness of central body
portion 101 to an end thickness to a lesser degree than does duck
bill end portion 102.
[0034] Prosthesis 120 may be implanted in a scleral pocket (i.e., a
passage either into and along or through or under the scleral layer
which has only on opening) rather than a scleral tunnel (a passage
either into, along and out of the scleral layer of through, under
and back through the scleral layer, with two openings, one at
either end). Preferably, however, prosthesis 120 is implanted in a
scleral tunnel with substantially all of central body portion 101
within the scleral tunnel (either within or under the scleral
layer) while duck bill end portion 102 and blunted end portion 105
are both substantially outside the scleral tunnel resting on the
outer surface of the sclera. Advantages of having blunted end
portion 105 outside the scleral tunnel are described in further
detail below.
[0035] Dashed line 190 within duck bill end portion 102 illustrates
that the end portions which are wider than the central body
portions of a prosthesis need not increase in width uniformly in
both directions (on both sides), but may instead increase in width
only on one side with the other side retaining planar alignment
with the side of the central body portion.
[0036] FIG. 1G is a top plan view of a prosthesis for increasing
the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention. The planform of the
central body portion 111 for prosthesis 130 in FIG. 1G is
circumferential--that is, shaped to follow a portion of a circle
around the lens of the eye. While the sides surfaces 160 and 161 of
central body portion 101 depicted in FIGS. 1A, 1C and 1E are
straight along a long axis of the respective prosthesis 100, 110 or
120, the side surfaces 162 and 163 of prosthesis 130 are both
curved along the long axis of prosthesis 130. Side surfaces 162 and
163 are both curved in the same direction (with side surface 162
being convex and side surface 163 being concave) and preferably
having a common focal point for the radius of curvature. However,
the two sides 162 and 163 may have differing degrees of curvature
(i.e., each having a different focal point for the respective
radius of curvature). The prosthesis 130 of FIG. 1G is intended to
be implanted within a scleral tunnel with side surface 162 further
from the lens than side surface 163. Use of an end portion which
widens only on one side (e.g., the outer edge) may be useful in
this embodiment and other embodiments where rotation of the
implanted prosthesis is much more likely in one direction than in
the opposite direction.
[0037] FIG. 1H is a top plan view of a prosthesis for increasing
the effective working distance of the ciliary muscle by
implantation into surgically formed scleral pockets or tunnels
according to another embodiment of the present invention. While the
sides surfaces 160 and 161 of central body portion 101 depicted in
FIGS. 1A, 1C and 1E are straight along a long axis of the
respective prosthesis 100, 110 or 120 and the side surfaces 162 and
163 of the central body portion 111 depicted in FIG. 1G are both
curved in the same direction, side surfaces 164 and 165 of the
central body portion 121 for prosthesis 140 are curved, along the
long axis of prosthesis 140, in opposite directions in the example
shown, both side surfaces 164 and 165 are concave, and have
identical curvatures (i.e., the same radius of curvature, although
with different focal, points). However, the side surfaces may
alternatively both be convex and/or may have different
curvatures.
[0038] In the example shown, end portions 102 and 103 are wider
than the wide point(s) of central body portion 121 (i.e., the ends
of the central body portion 121 for the embodiment depicted in FIG.
1H). In accordance with the present invention, however, end
portions 102 and 103 need only be wider than some portion of
central body portion 121 (i.e., should be wider than the narrowest
portion of central body portion 121) to improve stability of the
prosthesis 140 within the scleral tunnel.
[0039] It should be noted that while prostheses 130 and 140 are
depicted in FIGS. 1G and 1H as having equally sized duck bill end
portions 102 and 103 as described above with respect to prosthesis
100 depicted in FIG. 1A and 1B, either prosthesis 130 or 140 may
instead include a duck bill end portion at one end of central body
portion 111 or 121 which is smaller and/or thinner than the duck
bill end portion at the opposite end, in the manner of prosthesis
110 depicted in FIGS. 1C and 1D (end portions 102 and 104).
Likewise, either prosthesis 130 or 140 may alternatively include a
duck bill end portion at one end of central body portion 111 or 121
and a blunted end portion at the opposite end, in the manner of
prosthesis 120 depicted in FIGS. 1E and 1F (end portions 102 and
105).
[0040] FIG. 1I is a side elevation view of a prosthesis for
increasing the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention. While the bottom
surface 170 of the central body portion 101 depicted in FIGS. 1B,
1D and 1F is curved (concave) along a long axis of the prosthesis
100, 110 or 120, prosthesis 150 includes a central body portion 131
having a bottom surface 171 which is straight along the long axis
of prosthesis 150 (but which may be curved in other directions, as
described in further detail below). Alternatively, the bottom
surface of the central body portion may be convex along the long
axis of the prosthesis.
[0041] Central body portions 111 and 121 depicted in FIGS. 1G and
1H may have a bottom surface which is concave along the long axis
of the respective prosthesis 130 or 140, similar to central body
portion 101 in FIGS. 1B, 1D and 1F, flat along the long axis in the
manner depicted for central body portion 131 depicted in FIG. 1I,
or convex along the long axis. Moreover, while prostheses 150 is
depicted in FIG. 1I as having equally sized duck bill end portions
102 and 103 as described above with respect to prosthesis 100
depicted in FIG. 1A and 1B, prosthesis 150 may instead include
either: (1) a first duck bill end-portion at one end of central
body portion 131 which is smaller and/or thinner than a second duck
bill end portion at the opposite end, in the manner of prosthesis
110 depicted in FIGS. 1C and 1D (end portions 102 and 104); or (2)
a duck bill end portion at one end of central body portion 131 and
a blunted end portion at the opposite end, in the manner of
prosthesis 120 depicted in FIGS. 1E and 1F (end portions 102 and
109).
[0042] FIG. 1J is a side elevation view of a prosthesis for
increasing the effective working distance of the ciliary muscle by
implantation into surgically formed scleral tunnels according to
another embodiment of the present invention. While the, end
portions 102-105 are depicted in FIGS. 1B, 1D, 1F and 1I as being
substantially aligned with the respective central body portion 101
or 131, end portions 106 and 107 in prosthesis 160 are angled with
respect to central body portion 101. That is, the planes 180 and
181 with which end portions 106 and 107 are aligned (taken with
respect to the bottom surfaces 190 and 191 of end portions 106 and
107) are angled with respect to, and intersect, the plane 182 with
which central body portion 101 or 131 is aligned (again, taken with
respect to the bottom surface 170 or 171 of central body portion
101 or 131). By contrast, the planes with which end portions
102-105 are aligned are at least parallel with the planes to which
central body portions 101 and 131 are aligned; end portions 102-105
and central body portions 101 and 131 may, in fact, be aligned with
the same plane.
[0043] Such angling of end portions 106 and 107 with respect to the
central body portion 101 is preferably sufficient to allow the
bottom surfaces 190 and 191 to be substantially tangential to the
surface of the sclera on which such end portions 106 and 107 rest
when prosthesis 160 in implanted within a scleral tunnel. End
portions 102, 103 and/or 104 may also be angled with respect to the
corresponding central body portions 101, 111, 121 or 131 in the
prostheses 120, 130, 140 and 150 depicted in FIGS. 1C and 1F
through 1I. Moreover, only one end portion (e.g., end portion 102)
may be angled with respect to a central body portion, while the
opposite end portion (e.g., duck bill end portion 104 or blunted
end portion 105) may be substantially aligned with the
corresponding central body portion.
[0044] Those skilled in the art will understand that any of the
various alternative embodiments described or suggested above which
includes either no end portion or a blunted end portion at one end
of the respective prosthesis may be implanted within a scleral
pocket rather than a scleral tunnel.
[0045] FIGS. 2A and 2B are longitudinal cross-sectional views of
the central body portion of a prosthesis for increasing the
effective working distance of the ciliary muscle by implantation
into surgically formed scleral pockets or tunnels according to
various alternative embodiments of the present invention. FIGS. 2A
and 2B depict a cross-section taken along section lines A-A, along
a long axis of the prosthesis, with the end portions broken away.
The central body portion cross-sections 200 and 201 depicted in
FIGS. 2A and 2B may correspond to any of central body portions 101,
111 or 121 depicted in FIGS. 1A-1H and 1J.
[0046] As shown in both central body portion cross-sections 200 and
201, the top surface 172 of the central body portion has a convex
curvature along the long axis of the respective prosthesis (e.g.,
prosthesis 100, 110, 120, 130, 140 or 160). Alternatively, the top
surface of the central body portion may be straight or have a
concave curvature.
[0047] As illustrated in FIGS. 1B, 1D, 1F and 1J, bottom surface
170 has a concave curvature along a long axis of the respective
prosthesis. The bottom surface 170a may have a curvature which is
approximately equal to a curvature of the innermost surface 202 of
the scleral tunnel into which the prosthesis is to be implanted
(i.e., the curvature of the remaining scleral layer underlying the
scleral tunnel for an intra-scleral tunnel or, where the scleral
tunnel is formed between the sclera and the underlying tissue, of
the tissue underlying the scleral layer).
[0048] As illustrated in FIG. 2B and described in the '626
application, however, the bottom surface 170b may have a curvature
which is greater than the curvature of the innermost surface 202 of
the scleral tunnel (i.e., a smaller radius of curvature), such that
the prosthesis rests primary on the end portions and/or end regions
of the central body portion when implanted, with the bottom surface
170b in a middle area of the central body portion spaced apart from
the underlying innermost surface 202 of the scleral tunnel.
[0049] FIGS. 3A through 3E are transverse cross-sectional views of
the central body portion of a prosthesis for increasing the
effective working distance of the ciliary muscle by implantation
into surgically formed scleral pockets or tunnels according to
various alternative embodiments of the present invention. FIGS. 3A
through 3E depict a cross-section taken along section lines B-B,
transverse to a long axis of the prosthesis. The central body
portion cross-sections depicted in FIGS. 3A through 3E may
correspond to any of central body portions 101, 111, 121 or 131
depicted in FIGS. 1A-1J.
[0050] In the embodiment depicted in FIG. 3A, the bottom and top
surfaces 170a and 172a are both straight in a direction transverse
to the long axis of the prosthesis, as are side surfaces 160a and
161a. In the embodiment of FIG. 3B, however, while the top surface
172b and side surfaces 160b and 161b are al straight in directions
transverse to the long axis of the prosthesis, the bottom surface
170b is curved in a direction transverse to the long axis of the
prosthesis. The curvature of the example shown is approximately
equal to the curvature of the innermost surface 202 of the scleral
tunnel into which the prosthesis is to be implanted. The bottom
surface 170c in the embodiment of FIG. 3C is similarly curved in a
direction transverse to the long axis of the prosthesis, but with a
curvature greater than the curvature of the innermost surface 202
of the scleral tunnel. Top surface 172c and sides surfaces 160c and
161c are straight.
[0051] In the embodiment of FIG. 3D, the side surfaces 160d and
161d, while straight, are angled with respect to each other rather
than being substantially parallel. Top surface 172d has a convex
curvature in a direction transverse to the long axis of the
prosthesis, and bottom surface 170d has a concave curvature.
[0052] While the side surfaces 160d and 161d are uniformly or
equally sloped in the embodiment of FIG. 3D, the side surfaces may
be unequally sloped as shown in FIG. 3E to form an oblique profile.
Side surfaces 160e and 161e are straight, and sloped to different
degrees, while top surface 172e has a convex curvature and bottom
surface 170e has a concave, curvature.
[0053] Either or both of the side surfaces may alternatively be
curved, either convexly or concavely, in a direction transverse to
the long axis of the prosthesis, regardless of whether the side
surfaces are substantially parallel to each other or angled with
respect to each other. Moreover, the top surface may have a concave
curvature, or the bottom surface may have a convex curvature.
[0054] While reference is made to side surfaces 160 and 161 and top
and bottom surfaces 172 and 170 with respect to FIGS. 3A-3E, the
profiles and/or curvatures illustrated are equally applicable to
sides surfaces 162-165 or bottom surface 171. For example, while,
bottom surface 171 depicted in FIG. 1I is straight along a long
axis of the prosthesis, the same surface may be curved in a
direction transverse to the long axis in the manner illustrated in
FIGS. 3B-3C.
[0055] FIGS. 4A through 4D are transverse cross-sectional views of
duck bill end portions of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral pockets or tunnels according to various
alternative embodiments of the present invention. FIGS. 4A through
4D depict a cross-section taken along section lines C-C, transverse
to a long axis of the prosthesis, with the remainder of the
prosthesis broken away. The end portion cross-sections depicted in
FIGS. 4A through 4D may correspond to any of end portions 102, 103,
104, 106 or 107 depicted in FIGS. 1A-1J.
[0056] In the embodiment of FIG. 4A, the top and bottom surfaces
400a and 401a of the end portion are straight in a direction
transverse to the long axis of the prosthesis. Comparison of FIG.
3A with FIG. 4A shows that the prosthesis (which may be prosthesis
100, 110, 130, 140, 150 or 160) has a cross-section within the end
portions which is wider and thinner than the cross-section of the
central body portion. However, the cross-sectional circumference
and/or area of the end portions should preferably not be
significantly greater than the cross-sectional circumference and/or
area of the central body portion. In this manner, the end portion
may pass through an incision forming an opening to a scleral tunnel
intended to accommodate the central body portion without tearing.
The size of the surgical incision required to form a scleral tunnel
which will admit the central body portion of the prosthesis without
tearing (i.e., an incision having a length which is at least twice
the circumference of the cross-section of the central body portion)
will also permit passage of the end portion therethrough without
tearing.
[0057] Most preferably, the cross-sectional circumference and/or
area of the end portion intended to pass through the scleral tunnel
should be equal to or less than the cross-sectional circumference
and/or area of the corresponding central body portion. For this
reason, an embodiment such as that illustrated in FIG. 1C-1D, in
which one duck bill end portion is narrower and/or thinner than the
other, may be beneficially employed. Dashed outline 402 illustrates
a relative proportion for the differently sized duck bill end
portions.
[0058] FIG. 4B illustrates an embodiment including a top surface
400b which is straight but a bottom surface 401b which is curved
along a direction transverse to the long axis of the prosthesis.
The curvature of the bottom surface 401b in the example of FIG. 4B
is approximately equal to the curvature of the scleral surface 403
upon which the respective end portion is intended to rest following
implantation of the prosthesis.
[0059] FIG. 4C similarly illustrates an embodiment including a top
surface 400c which is straight but a bottom surface 401c which is
curved along a direction transverse to the long axis of the
prosthesis. However, the curvature of the bottom surface 401c in
FIG. 4C is greater than the curvature of the sclera surface 403
upon which the respective end portion is intended to rest following
implantation of the prosthesis. In this manner, the force of
contact between the duck bill end portions and the underlying
sclera occurs near the edge of the respective end portion,
maximizing the effect of the end portion in preventing rotation of
the implanted prosthesis.
[0060] FIG. 4D illustrates an embodiment in which both the top
surface 400d and the bottom surface 401d which is curved along a
direction transverse to the long axis of the prosthesis.
[0061] FIGS. 5A and 5B are longitudinal cross-sectional views of
duck bill end portions of a prosthesis for increasing the effective
working distance of the ciliary muscle by implantation into
surgically formed scleral pockets or tunnels according to various
alternative embodiments of the present invention. FIGS. 5A and 5D
depict a cross-section of an end portion taken along section lines
A-A with the remainder of the prosthesis broken away. The end
portion cross-sections depicted in FIGS. 5A and 5B may correspond
to any of end portions 102, 103, 104, 106 or 107 depicted in FIGS.
1A-1J.
[0062] FIG. 5A depicts an embodiment in which the top surface 500a
is straight but the bottom surface 501a of a duck bill end portion
is curved along the long axis of the prosthesis, at least in a
central area of the end portion (i.e., the cross-section may be
straight near an edge of the end portion). The curvature of the
bottom surface 501a in the example of FIG. 5A is approximately
equal to the curvature of the scleral surface 403 upon which the
respective end portion is intended to rest following implantation
of the prosthesis.
[0063] FIG. 5B depicts an embodiment in which both the top surface
500b and the bottom surface 501a of a duck bill end portion are
curved along the long axis of the prosthesis, at least in a central
area of the end portion.
[0064] FIG. 6 is a longitudinal cross-section of a blunted end
portion of a prosthesis for increasing the effective working
distance of the ciliary muscle by implantation into surgically
formed scleral pockets or tunnels according to one embodiment of
the present invention. Blunted end portion 105 includes one or more
grooves 600 or 601, in the bottom surface, the top surface or both.
Although not shown in FIG. 1F, grooves 600 and 601, if present,
preferably extend across an entire width of the end portion 105.
Grooves may be uniform, similar to groove 601, or oblique, similar
to groove 600, and are intended to "catch" the lip of a scleral
incision through which the prosthesis is inserted to inhibit
sliding of the prosthesis within the scleral tunnel.
[0065] The dimensions of the central body portion of the prosthesis
of the present invention are similar to the overall prosthesis
dimension (including lengths, widths, thickness, and radii of
curvature/heights for various curved surfaces) given in the related
applications identified above. The prosthesis of the present
invention may be fabricated of the same materials, and in the same
manner, as those described in the related applications.
Additionally, in treatment of eye disorders utilizing the
prosthesis of the present invention, a number of prostheses are
implanted in a single eye in the same manner as described in the
related applications.
[0066] The present invention has been described in detail. Those
skilled in the art will understand that various changes,
substitutions and alterations may be made herein without departing
from the spirit and scope of the invention in its broadest
form.
* * * * *