U.S. patent application number 10/242977 was filed with the patent office on 2003-03-13 for lens for increased depth of focus.
Invention is credited to Cumming, J. Stuart.
Application Number | 20030050696 10/242977 |
Document ID | / |
Family ID | 23458799 |
Filed Date | 2003-03-13 |
United States Patent
Application |
20030050696 |
Kind Code |
A1 |
Cumming, J. Stuart |
March 13, 2003 |
Lens for increased depth of focus
Abstract
An intraocular lens provides substantially increased depth of
focus for accurate near and far vision with an optic much thinner
than a natural lens, and the lens being rigid vaulted posteriorly
and adapted for posterior positioning in the capsular bag. The
optic is positioned substantially farther from the cornea than a
natural lens, so that a cone of light exiting the optic to impinge
upon the retina is much smaller than a cone of light from a natural
lens. Typically, the optic may be about 1.0 mm thick and its
distance from the cornea 7.0-8.0 mm.
Inventors: |
Cumming, J. Stuart; (Laguna
Beach, CA) |
Correspondence
Address: |
FULBRIGHT & JAWORSKI, LLP
1301 MCKINNEY
SUITE 5100
HOUSTON
TX
77010-3095
US
|
Family ID: |
23458799 |
Appl. No.: |
10/242977 |
Filed: |
September 13, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10242977 |
Sep 13, 2002 |
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09370235 |
Aug 9, 1999 |
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6451056 |
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Current U.S.
Class: |
623/6.37 ;
623/6.4 |
Current CPC
Class: |
A61F 2002/1689 20130101;
A61F 2/1629 20130101; A61F 2002/1699 20150401 |
Class at
Publication: |
623/6.37 ;
623/6.4 |
International
Class: |
A61F 002/16 |
Claims
The inventor claims:
1. An intraocular lens for increased depth of focus, comprising: an
optic having a thickness substantially less than a natural human
lens, and at least two haptics connected with the optic, said lens
being adapted to be posteriorly positioned in the capsular bag of
the eye, whereby light refracted by the cornea travels
substantially farther to the optic than with a natural optic and a
substantially smaller cone of light passes from the optic to the
retina to provide substantially increased depth of focus.
2. A lens according to claim 1, wherein the optic is about 1.0 mm
in thickness.
3. A lens according to claim 1, wherein the optic has a thickness
between 0.05 mm and 1.5 mm.
4. A lens according to claim 1, wherein the lens is rigid and the
haptics are rigidly connected with the optic and extend
therefrom.
5. A lens according to claim 1, wherein the lens is configurated to
vault posteriorly in the capsular bag of the eye.
6. A lens according to claim 4, wherein the lens is configurated to
vault posteriorly in the capsular bag.
7. A lens according to claim 4, wherein the optic has a thickness
between 0.50 mm and 1.5 mm.
8. A lens according to claim 5, wherein the optic has a thickness
between 0.60 mm and 1.5 mm.
9. A lens according to claim 4, wherein: the rigid lens is moved
anteriorly for near vision and posteriorly for far vision by
changes in ciliary muscle configuration during contraction.
10. A lens according to claim 9, wherein: a peripheral equator of
the capsular bag and the rigid lens therein are moved about 1.0 mm
between their far and near vision positions, whereby the optic is
positioned about 1.0 mm further anteriorly than posteriorly to
provide improved near vision.
11. A lens according to claim 9, wherein: redistribution of ciliary
muscle mass upon constriction of the muscle for near vision causes
encroachment thereof on the vitreous cavity and an increase of
pressure therein to aid in urging the rigid lens anteriorly to
enhance near vision.
12. An intraocular lens for increased depth of focus, comprising:
an optic having a thickness substantially less than the thickness
of a natural human lens, and two haptics rigidly connected to the
optic and extending therefrom, said lens being configurated to
vault posteriorly in the capsular bag to position the optic farther
from the cornea of the eye, whereby light refracted by the cornea
travels substantially farther to the optic than with a natural
optic and a substantially smaller cone of light passes from the
optic to the retina to provide substantially increased depth of
focus.
13. A lens according to claim 12, wherein the optic has a thickness
between 0.05 mm and 1.5 mm.
14. A lens according to claim 12, wherein: the rigid lens is moved
anteriorly for near vision and posteriorly for far vision by
changes in ciliary muscle configuration during contraction.
15. A lens according to claim 13, wherein: the rigid lens is moved
anteriorly for near vision and posteriorly for far vision by
changes in ciliary muscle configuration during contraction.
16. A lens according to claim 14, wherein: redistribution of
ciliary muscle mass upon constriction of the muscle for near vision
causes encroachment thereof on the vitreous cavity and an increase
of pressure therein to aid in urging the rigid lens anteriorly to
enhance near vision.
17. A lens according to claim 14, wherein: a peripheral equator of
the capsular bag and the rigid lens therein are moved about 1.0 mm
between their far and near vision positions, whereby the optic is
positioned about 1.0 mm further anteriorly than posteriorly to
provide improved near vision.
18. A lens according to claim 12, wherein: a peripheral equator of
the capsular bag and the rigid lens therein are moved about 1.0 mm
between their far and near vision positions, whereby the optic is
positioned about 1.0 mm further anteriorly than posteriorly to
provide improved near vision.
19. A lens according to claim 4, and further comprising at least
one rigid bar secured to and extending longitudinally of the lens
to provide rigidity.
20. A lens according to claim 19, wherein said lens is
longitudinally flexible for bending for insertion into an eye.
21. A lens according to claim 12, and further comprising at least
one rigid bar secured to and extending longitudinally of the lens
to provide rigidity.
22. A lens according to claim 21, wherein said lens is
longitudinally flexible for bending for insertion into an eye.
23. A lens according to claim 21, wherein two rigid bars are
disposed in spaced relation and extend longitudinally of the lens.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] A natural human optic typically has a thickness of about 5.0
mm. Light rays entering the cornea and passing to the optic
typically travel about 7.0 to 8.0 mm. Light rays pass from the
optic in a cone of light with its apex at the retina. The natural
lens provides only a limited degree of depth of focus with clear
vision over a limited range of distances.
[0002] The present invention provides an optic which is only a
fraction the thickness of the natural lens. Whereas the natural
lens is about 5.0 mm thick, the lens of the invention may typically
be 1.0 mm and may range from about 0.5 mm to 1.5 mm. The distance
from the cornea to the optic of the invention is about 7.0-8.0 mm,
whereas with a natural lens, the light rays travel only about 3.5
mm from cornea to optic. Light rays refracted by and exiting the
optic define a cone of light much smaller in cross-sectional area
than the natural lens, and therefore impinge on the retina in a
smaller area. The much smaller cone provides greatly increased
depth of focus in comparison with a natural lens, and thus enables
clear vision over a long range of distances. In effect, the
invention provides effective accommodation as between near and far
vision, and a person is enabled to view accurately over a wide
range of distances. The optic is positioned much farther from the
cornea than a natural lens, and this increase of distance minimizes
the distance optical power change. The further posterior the optic,
the higher the power of the optic and the less movement required
for a given power change. The lens according to the invention is
rigid, the haptics being rigidly connected to the optic, and the
lens is vaulted posteriorly. Thus, the distance between the cornea
and the optic is maximized and the distance of travel of light rays
between cornea and optic is increased.
[0003] The rigid lens causes the optic to move with the periphery
of the capsular bag in response to ciliary muscle changes,
particularly for near vision.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a cross-sectional view of a frontal portion of a
human eye with a lens according to the invention disposed
therein;
[0005] FIG. 2 is a partial sectional view of an eye showing light
rays entering the cornea and exiting the optic in a cone of light
from a natural lens to the retina;
[0006] FIG. 3 is a view similar to that of FIG. 2, showing an optic
according to the invention, and light rays exiting the optic in a
cone of light of smaller size than with the natural lens of FIG.
2;
[0007] FIGS. 4 and 5 are sectional views taken respectively at line
4-4 and line 5-5 in FIG. 1, showing a capsular bag and haptic in
relation to the ciliary muscle in near and far vision positions of
the capsular bag and haptic;
[0008] FIG. 6 is a diagrammatic sectional view of the ciliary
muscle and capsular bag showing in solid lines their near vision
positions, and showing in broken lines their far vision
positions;
[0009] FIG. 7 is an elevational view of a preferred embodiment of
lens and haptic according to the invention;
[0010] FIG. 8 is a side elevational view of the lens of FIG. 7;
[0011] FIG. 9 is an elevational view of another preferred
embodiment of lens according to the invention; and
[0012] FIG. 10 is a side elevational view of the lens of FIG.
9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] The present invention provides substantially increased depth
of focus, for effective near and far accurate vision by providing a
thin optic which is only a fraction the thickness of a natural lens
or a conventional artificial lens optic, and by providing a rigid
lens adapted to be positioned posteriorly in the natural capsular
bag.
[0014] Referring to the drawings, FIG. 1 is a cross-sectional view
of an eye 10 with a cornea 12, with a lens 14 according to the
invention disposed in the capsular bag 16 of the eye. As indicated
in FIG. 2, light rays entering at the cornea are refracted and
impact a natural lens 14 which refracts the rays to define a cone
of light which impacts the retina. FIG. 3 is a partial sectional
view showing a thin optic 18 of the invention disposed
substantially farther posteriorly than the natural lens 14 (or a
conventional artificial lens) of 5 mm thickness (d.sub.2 in FIG.
2). The light rays passing from the cornea to the optic 18 must
travel a distance of about 7.0 to 8.0 mm from the cornea to the
optic, whereas with the natural lens 14 light rays travel only
about 3.5 mm. The light rays refracted by and exiting the optic 18
define a cone of light of much smaller cross-sectional area (FIG.
3A) impact the retina in a smaller area, in comparison with the
much larger cone of light and its much larger cross section (FIGS.
2 and 2A). An optic according to the invention may typically be 1.0
mm thick (d.sub.1 in FIG. 3), and may range from about 0.5 to about
1.5 mm in thickness.
[0015] The much smaller cone of light provides greatly increased
depth of focus, thus enabling clear vision over a long range of
distances, in comparison with the much larger cone of light
produced by the natural human lens or conventional artificial
intraocular lens. The much improved depth of focus provides
effective accommodation or "pseudo accommodation", as between near
and far vision, so that a person is enabled to view accurately over
a wide range of distances. The increase of distance which light
rays must travel between the cornea and the optic minimizes the
distance optical power change--i.e., the further posterior the
optic, the higher the power of the optic and the less movement
required for significant power change.
[0016] The lens 14 according to the invention is rigid, with the
haptics thereof rigidly connected with the optic. The lens is
vaulted posteriorly, as shown in FIGS. 1 and 8, in order to
maximize the posterior positioning of the optic to increase the
distance of travel of light rays between the cornea and the optic.
Additional rigidity may be provided by rigid bars 20 secured along
the edges of the lens (FIG. 7) or as shown in FIG. 9, a lens 22 may
have rigid bars 24 disposed inwardly of the lens edges with arcuate
portions extending about the optic, as shown. The haptics are
preferably flexible to enable folding for insertion of the lens
into the human eye via a slot therein of relatively short length.
Lenses according to the invention may preferably embody upper and
lower flexible loop portions 26, 26 (FIG. 7) which extend
oppositely to facilitate lens rotation during insertion into an
eye, without interfering engagement with the capsular bag.
[0017] The outer peripheral equator portion of the capsular bag is
moved in response to configurational changes in the ciliary muscle
as between near and far vision, thereby causing the lens and its
optic to move with the periphery of the capsular bag in response to
such muscle changes, particularly with respect to near vision. That
is, upon contraction of the ciliary muscle, anterior displacement
of the capsular bag equator effects corresponding anterior movement
of the optic. The lens and optic are free to move anteriorly
because of the relative stiffness of the anterior bag resulting
from leather-like fibrosis or dead tissue arising from conventional
surgical cutting to remove the anterior portion of the bag. The
lens is moved posteriorly only when the muscle acts thereon.
[0018] FIGS. 4, 5 and 6 are diagrammatic cross-sectional views of
the ciliary muscle 28 of the eye in relation to the peripheral or
equator portion of the capsular bag with the lens 14 of the
invention therein. FIG. 6 shows in broken lines the configuration
30 of the muscle 28 and the relative position of the haptic 14, in
a far vision position, and showing in solid lines 32, the muscle
configuration 30 and relative position of the haptic for near
vision. Muscle configuration indicated at 30 extends into vitreous
cavity, thus increasing pressure to a limited degree to further aid
in moving the lens anteriorly. Muscle constriction moves the rigid
lens forward to a limited degree at the bag periphery, the whole
lens moving forwardly.
[0019] Thus there has been shown and described a lens for increased
depth of focus which fulfills all the objects and advantages sought
therefor. Many changes, modifications, variations and other uses
and applications of the subject invention will, however, become
apparent to those skilled in the art after considering this
specification together with the accompanying drawings and claims.
All such changes, modifications, variations and other uses and
applications which do not depart from the spirit and scope of the
invention are deemed to be covered by the invention which is
limited only by the claims which follow.
* * * * *