U.S. patent application number 12/935287 was filed with the patent office on 2011-02-03 for methods and devices for refractive corrections of presbyopia.
Invention is credited to Junzhong Liang.
Application Number | 20110029073 12/935287 |
Document ID | / |
Family ID | 41136053 |
Filed Date | 2011-02-03 |
United States Patent
Application |
20110029073 |
Kind Code |
A1 |
Liang; Junzhong |
February 3, 2011 |
Methods and Devices for Refractive Corrections of Presbyopia
Abstract
Presbyopia in a patient's eye is treated by inducing spherical
aberration in the central section of the pupil, while the
peripheral section of the pupil is treated in a manner other than
the central section of the pupil. For example, the peripheral
section of the pupil may remain untreated, or high-order aberration
may be controlled, and/or a second area of spherical aberration may
be provided with different focus power.
Inventors: |
Liang; Junzhong; (Fremont,
CA) |
Correspondence
Address: |
THE MUELLER LAW OFFICE, P.C.
12951 Harwick Lane
San Diego
CA
92130
US
|
Family ID: |
41136053 |
Appl. No.: |
12/935287 |
Filed: |
March 31, 2009 |
PCT Filed: |
March 31, 2009 |
PCT NO: |
PCT/US2009/001980 |
371 Date: |
September 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61072653 |
Apr 2, 2008 |
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Current U.S.
Class: |
623/5.11 ;
351/159.12 |
Current CPC
Class: |
A61F 2/1648 20130101;
A61F 9/00808 20130101; A61F 2/145 20130101; G02C 7/028 20130101;
A61F 2009/00872 20130101; G02C 7/02 20130101; A61F 2/1613 20130101;
A61F 2/147 20130101; A61F 9/00812 20130101; G02C 7/044 20130101;
G02C 7/061 20130101; A61F 2009/0088 20130101; G02C 7/042 20130101;
A61F 2/164 20150401 |
Class at
Publication: |
623/5.11 ;
351/171; 351/161; 351/164; 351/168; 351/169 |
International
Class: |
A61F 2/14 20060101
A61F002/14; G02C 7/06 20060101 G02C007/06; G02C 7/04 20060101
G02C007/04; G02C 7/10 20060101 G02C007/10 |
Claims
1. A corneal implant device for surgical implantation between
layers and in an optic zone of a cornea of an eye for treatment of
presbyopia, comprising a solid transparent optic having a diameter
of equal or less than 6.5 mm, wherein the device is configured such
that, when implanted in the eye, spherical aberration or a
distribution of spherical aberrations is created in a central area
of a pupil, wherein the central area of the pupil has a diameter of
between 1.5 mm and 4.0 mm, and wherein the spherical aberration or
the distribution of spherical aberrations is created only by the
presence of said device.
2. The device of claim 1, wherein said device is configured to have
a circular shape with a radial distance expressed by r, and wherein
the device is further configured to have a thickness profile in a
central portion that is expressed at least in part by r.sup.4 to so
allow creation of the spherical aberration or a distribution of
spherical aberrations.
3. The device of claim 1, wherein the device is configured such
that the spherical aberration or the distribution of spherical
aberrations allows production of a focus variation selected from
the group consisting of (a) setting a far point at a center of the
device and having a radially increased refractive power, (b) having
a radially decreased refractive power and setting a portion of the
eye for hyperopia, and (c) having at least one zone with a radially
increased refractive power another zone with a radially decreased
refractive power and setting a portion of the eye for
hyperopia.
4. The device of claim 1, wherein the device is configured such
that the spherical aberration or the distribution of spherical
aberrations can produce a focus variation of more than 4
diopters.
5. The device of claim 1, wherein the device is made of
biocompatible materials suitable for corneal implantation.
6. The device of claim 1, wherein the device is further configured
to have refractive powers for correction of at least one of focus
error, astigmatism, and coma in the eye.
7. A method of treating presbyopia, comprising: (a) measuring
refractive properties of an eye; and (b) removing corneal tissue to
create a spherical aberration or a distribution of spherical
aberrations in a central portion of a pupil of an eye, wherein the
central portion is equal or less than 4 mm in diameter.
8. The method of claim 7, wherein the spherical aberration or the
distribution of spherical aberrations produces a focus variation
selected from the group consisting of (a) setting a far point at a
center of the pupil and having a radially increased refractive
power, (b) having a radially decreased refractive power and setting
a portion of the eye for hyperopia, and (c) having at least one
zone with a radially increased refractive power and another zone
with a radially decreased refractive power and setting a portion of
the eye for hyperopia.
9. The method of claim 7, wherein spherical aberration or a
distribution of spherical aberrations produces a focus variation
more than 4 diopters.
10. The method of claim 7, further comprising a step of removing
corneal tissue for additional refractive correction of at least one
of myopia, hyperopia, and cylindrical error in the eye.
11. The method of claim 10, wherein the step of removing corneal
tissue is achieved by applying photon energy to the corneal
tissue.
12. A lens for the treatment of presbyopia of an eye, comprising:
an inner optical section of 1.5 mm to 3.6 mm in diameter, wherein
the inner optical section comprises at least one aspheric surface,
wherein the aspheric surface is configured to allow creation of a
spherical aberration or a distribution of spherical aberrations in
addition to a spherical focus power; a middle optical section
having an outer diameter of 2.5 mm to 5 mm, wherein the middle
optical section is configured as a bi-focal lens; and an outer
optical section having an outer diameter of 4 mm to 40 mm, wherein
the outer optical section is configured to have a dominant focus
power.
13. The lens of claim 12, wherein the spherical aberration or the
distribution of spherical aberrations allows production of a focus
variation selected from the group consisting of (a) setting a far
point at a center of the lens and having a radially increased
refractive power, (b) having a radially decreased refractive power
and setting a portion of the eye for hyperopia, and (c) having at
least one zone with a radially increased refractive power another
zone with a radially decreased refractive power and setting a
portion of the eye for hyperopia.
14. The lens of claim 12, wherein the lens is configured such that
the spherical aberration or the distribution of spherical
aberrations allows production of a focus variation of more than 4
diopters.
15. The lens of claim 12, wherein the lens is configured as an
implantable lens or a wearable lens.
16. The lens of claim 12 wherein the lens is further configured to
allow production of a cylindrical refractive power.
17. An optical device for refractive treatment of presbyopia
comprising: an inner transparent optical section that comprises at
least one aspheric surface that is configured to allow induction of
a spherical aberration or a distribution of spherical aberrations
in addition to a spherical focus power; a middle section that is
configured to allow attenuation or blocking of light energy; and an
outer transparent optical section that is configured to provide at
least a spherical focus power for far vision at night.
18. The device of claim 17, wherein the device is configured such
that the spherical aberration or the distribution of spherical
aberrations allows production of a focus variation selected from
the group consisting of (a) setting a far point at a center of the
device and having a radially increased refractive power, (b) having
a radially decreased refractive power and setting a portion of the
eye for hyperopia, and (c) having at least one zone with a radially
increased refractive power another zone with a radially decreased
refractive power and setting a portion of the eye for
hyperopia.
19. The device of claim 17, wherein the device is configured such
that the spherical aberration or the distribution of spherical
aberrations allows production of a focus variation of more than 4
diopters.
20. The device of claim 17, wherein the inner transparent optical
section has a diameter of between 1.5 mm and 3.6 mm.
21. The device of claim 17, wherein an outer diameter of the middle
section is between 2.5 mm and 5 mm.
22. The device of claim 17, wherein an outer diameter of the outer
transparent optical section is between 4 mm and 40 mm.
23. The device of claim 17, wherein the device is configured to
produce a cylindrical refractive power.
24. The device of claim 17, wherein the device is configured as an
implantable lens or a wearable lens.
25. A lens for the treatment of presbyopia of an eye comprising: an
inner optical section having a diameter of 1.5 mm to 4 mm and
comprising at least one aspheric surface that is configured to
allow induction of a spherical aberration or a distribution of
spherical aberrations in addition to a spherical focus power; and
an outer transparent optical section having a diameter of 4 mm to
40 mm, wherein the outer transparent optical section is configured
to have at least a spherical focus power for far vision at
night.
26. The lens of claim 25, wherein the lens is configured such that
the spherical aberration or the distribution of spherical
aberrations allows production of a focus variation for more than 4
diopters in a manner selected from the group consisting of (a)
setting a far point at a center of the lens and having a radially
increased refractive power, (b) having a radially decreased
refractive power and setting a portion of the eye for hyperopia,
and (c) having at least one zone with a radially increased
refractive power another zone with a radially decreased refractive
power and setting a portion of the eye for hyperopia.
Description
[0001] This application claims priority to U.S. provisional
application with the Ser. No. 61/072,653 titled "Methods and
devices for treatments of presbyopia" filed Apr. 2, 2008.
FIELD OF THE INVENTION
[0002] The field of the invention relates to refractive correction
of human eyes, in particular, for refractive treatments of
presbyopia.
BACKGROUND OF THE INVENTION
[0003] Presbyopia is an age-related problem with near vision, due
to progressive reduction in the eye's ability to focus, with
consequent difficulty in reading at the normal distance. An
effective refractive correction of presbyopia must provide focus
for far, intermediate, and near vision in all conditions of pupil
size. p Diffractive intraocular lenses (IOLs) such as those
described in U.S. Pat. No. 5,116,111 by Michael Simpson and John
Futhey and in US 2006/0116764A1 by Michael Simpson can provide
simultaneous bi-focus (far vision and near vision) correction for
presbyopia, but have two inherent disadvantages: Degraded night
vision with night glare caused by light scattering at the junctions
of diffractive zones in the lens surface, and a blind spot at
intermediate distance between the far and near focus points.
[0004] Multifocal designs by controlling light distribution for
far, intermediate, and near vision across different aperture size
of a lens were proposed by Valdmar Portney in U.S. Pat. Nos.
5,225,858 and 6,557,998B2. These lens designs can perform better
for intermediate vision than Simpson's diffractive IOLs, but are
also known to be inferior for performance at near vision. Moreover,
Portney's lenses fail to achieve their full potential as they are
based on simple geometric ray tracing, without taking into account
a diffraction effect of light propagation.
[0005] Aspheric lenses were also proposed in U.S. Pat. No.
6,923,539B2 by Michael Simpson and in U.S. Pat. Nos. 5,166,711 and
6,409,340B1 by Valdmar Portney. These lenses have a periodic
refractive power distribution across a lens. While Simpson's lens
can increase focus depth for a mono-focal lens as illustrated in
FIG. 9 of U.S. Pat. No. 6,923,539B2, such lens is typically not
suitable for presbyopic correction.
[0006] Spherical aberration across the pupil of an eye produces
different focusing power at different pupil radii. Negative
spherical aberration across pupil of an eye was proposed for
mitigation of presbyopia by Seema Somani and Kingman Yee in U.S.
Pat. No. 7,261,412 B2. There, the inventors noted that negative
spherical aberration across the entire pupil can shift the center
of the focus range from far to an intermediate distance because
negative spherical aberration produces focus power for far vision
at the pupil center to intermediate vision at the pupil
periphery.
[0007] However, inducing spherical aberration across an entire
pupil of an eye has at least two limitations for presbyopic
corrections. First, the total amount of spherical aberration
induced across the pupil cannot be too strong to cause nighttime
symptoms such as glare and starburst, which is the one of the
fundamental reasons why lenses with significant spherical
aberration have not been used in multifocal IDLs and contact lenses
for presbyopic treatments. Second, Somani and Yee's method in U.S.
Pat. No. 7,261,412 B2 is typically not sufficient for presbyoic
treatments because the small amount of spherical aberration across
the entire pupil only shifts the center of focus range and does not
increase focus depth. Still further, currently known methods of
spherical aberration for presbyopic corrections have failed to
address issues of induced nighttime symptoms (glare, starburst) and
increase focus depth of an eye for far vision, intermediate vision
and near vision, thus rendering such solutions less than
desirable.
[0008] Consequently, although many configurations and methods for
vision correction for treatment of presbyopia are known in the art,
all or almost all of them suffer from one or more disadvantages.
Thus, there is still a need to provide improved configurations and
methods for vision correction for treatment of presbyopia.
SUMMARY OF THE INVENTION
[0009] The present inventive subject matter is drawn to methods and
devices for refractive treatment of presbyopia.
[0010] According to one embodiment of the invention, a corneal
implant device for surgical implantation between the layers and in
the optic zone of a cornea of an eye for treatment of presbyopia
comprises a solid transparent optic less than 6.5 mm in diameter,
wherein when implanted in the eye spherical aberration or a
distribution of spherical aberrations is created in the central
pupil between 1.5 mm and 4.0 mm in diameter only by the presence of
said device.
[0011] According to another embodiment of the invention, a
procedure for treatment of presbyopia comprises the steps of
measuring refractive properties of an eye; removing corneal tissue
to create spherical aberration or a distribution of spherical
aberrations in the central pupil of an eye less than 4 mm in
diameter.
[0012] According to another embodiment of the invention, a lens for
the treatment of presbyopia of an eye comprises an inner optical
section of 1.5 mm to 4 mm in diameter that contains at least one
aspheric surface to induce spherical aberration or a distribution
of spherical aberrations in addition to a spherical focus power; an
outer transparent optical section of 4 mm to 40 mm in diameter that
is configured to have a dominant spherical focus power.
[0013] According to another embodiment of the invention, a lens for
the treatment of presbyopia of an eye comprises an inner optical
section of 1.5 mm to 3.6 mm in diameter, wherein the inner optical
section contains at least one aspheric surface to create spherical
aberration or a distribution of spherical aberrations in addition
to a spherical focus power; an middle optical section with an outer
diameter of 2.5 mm to 5 mm that is configured to be a bi-focal
lens; and an outer optical section with an outer diameter of 4 mm
to 40 mm that is configured to have a dominant focus power.
[0014] According to another embodiment of the invention, an optical
device for refractive treatment of presbyopia comprises an inner
transparent optical section that contains at least one aspheric
surface to induce spherical aberration or a distribution of
spherical aberrations in addition to a spherical focus power; a
middle section that is configured to attenuate or block light
energy; and an outer transparent optical section that is configured
to have a dominant spherical focus power.
[0015] Various objects, features, aspects and advantages of the
present invention will become more apparent from the following
detailed description of preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
[0016] FIG. 1A shows a front view of an eye's optics that is
divided into two optical sections: a central optical zone and an
outer optical zone.
[0017] FIG. 1B shows a wavefront map for a refractive correction of
presbyopia in a method of introducing spherical aberration only at
a central pupil section of an eye.
[0018] FIG. 1C shows the radial distribution of refractive power
derived from the wavefront map in FIG. 1B.
[0019] FIG. 1D shows a wavefront map for a refractive correction of
presbyopia in a method of introducing a distribution of spherical
aberrations only at a central pupil section of an eye.
[0020] FIG. 1E shows the radial distribution of a refractive power
derived from the wavefront map in FIG. 1D.
[0021] FIG. 2 shows the calculated MTFs (modulation transfer
functions) of an eye with a wavefront map specified in FIG. 1B for
three pupil sizes and at 3 different focus positions.
[0022] FIG. 3 shows the calculated MTFs of an eye with a wavefront
map specified in FIG. 1D for three pupil sizes and at 4 different
focus positions.
[0023] FIG. 4A shows a schematic diagram of a refractive element to
be implanted into an eye for refractive corrections of
presbyopia.
[0024] FIG. 4B shows a radial distribution of refractive power for
the refractive element in FIG. 4A in one embodiment.
[0025] FIG. 4C shows a radial distribution of refractive power for
the refractive element in FIG. 4A in another embodiment.
[0026] FIG. 4D shows a radial distribution of refractive power for
the refractive element in FIG. 4A in yet another embodiment.
[0027] FIG. 4E shows schematic diagrams of a refractive element
that can be worn on or implanted into an eye for refractive
correction of presbyopia.
[0028] FIG. 4F shows a radial distribution of refractive power for
the refractive element in FIG. 4E in one embodiment that has a
gradually increased refractive power in the central optical section
and a constant refractive power beyond the central optical
section.
[0029] FIG. 4G shows a radial distribution of refractive power for
the refractive element in FIG. 4E in an embodiment that has a
gradually increased refractive power in the central optical section
and a custom focus offset, depending on spherical aberration in an
individual eye, beyond the central optical section.
[0030] FIG. 4H shows a radial distribution of refractive power for
the refractive element in FIG. 4E in one embodiment that has a
gradually increased refractive power in the central optical section
and a different radial distribution of refractive power beyond the
central optical section.
[0031] FIG. 4I shows a radial distribution of refractive power for
the refractive element in FIG. 4E in one embodiment that has a
gradually reduced refractive power in the central optical section
and a constant refractive power beyond the central optical
section.
[0032] FIG. 4J shows a radial distribution of refractive power for
the refractive element in FIG. 4E in an embodiment that has a
gradually reduced refractive power in the central optical section
and a custom focus offset, depending on spherical aberration in an
individual eye, beyond the central optical section.
[0033] FIG. 4K shows a radial distribution of refractive power for
the refractive element in FIG. 4E in one embodiment that has a
gradually reduced refractive power in the central optical section
and a different radial distribution of refractive power beyond the
central optical section.
[0034] FIG. 4L shows a radial distribution of refractive power for
the refractive element in FIG. 4E in one embodiment that has a
first zone of reduced refractive power and a second zone of
increased refractive power in the central optical section, and a
constant refractive power beyond the central optical section.
[0035] FIG. 4M shows a radial distribution of refractive power for
the refractive element in FIG. 4E in an embodiment that has a zone
of reduced refractive power and a zone of increased refractive
power in the central optical section, and a custom focus offset,
depending on spherical aberration in an individual eye, beyond the
central optical section.
[0036] FIG. 4N shows a radial distribution of refractive power for
the refractive element in FIG. 4E in one embodiment that has a zone
of reduced refractive power and another zone of increased
refractive power in the central optical section, and a different
radial distribution of refractive power beyond the central optical
section.
[0037] FIG. 5A shows a schematic diagram of a refractive element to
be worn on or implanted in an eye for refractive correction of
presbyopia.
[0038] FIG. 5B shows a schematic diagram of another refractive
element to be worn on or implanted in an eye for refractive
correction of presbyopia.
[0039] FIG. 5C shows a radial distribution of refractive power for
a refractive element in FIG. 5B in one embodiment.
[0040] FIG. 6A shows a schematic diagram of yet another refractive
element to be worn on or implanted in an eye for refractive
correction of presbyopia.
[0041] FIG. 6B shows a schematic diagram of an additional
refractive element to be worn on or implanted in an eye for
refractive correction of presbyopia.
[0042] FIG. 7A shows a schematic diagram of a refractive element
that can be worn on or implanted into an eye for refractive
correction of presbyopia.
[0043] FIG. 7B shows a side view of the refractive element in FIG.
7A that can be worn on or implanted into an eye for refractive
correction of presbyopia.
[0044] FIG. 7C shows a radial distribution of refractive power for
the refractive element in FIG. 7A in one embodiment.
[0045] FIG. 7D shows a radial distribution of refractive power for
the refractive element in FIG. 7A in another embodiment.
[0046] FIG. 7E shows a radial distribution of refractive power for
the refractive element in FIG. 7A in yet another embodiment.
DETAILED DESCRIPTION
[0047] Before describing wave front technologies for refractive
correction of presbyopia, it must be emphasized that the refractive
elements described in the present invention may include a baseline
refractive correction of conventional refractive errors like
myopia, hyperopia and astigmatism. For simplicity, the disclosed
shapes (refractive powers and wavefront maps) only include the
added wavefront map or refractive powers beyond the baseline
correction for increasing focus depth from far vision to near
vision. [0048] I. Methods for refractive corrections of presbyopia
by introducing spherical aberration or a distribution of spherical
aberrations only at pupil center of an eye
[0049] FIG. 1A shows a schematic diagram of an eye's optics that is
divided into two optical sections: the central optical section 10
less than 4.5 mm in diameter and the periphery pupil section 11 up
to 8 mm in diameter. The dotted circle in FIG. 1A indicates the
iris (pupil) of an eye at night. Diameter of an eye's pupil at
night is different from eye to eye, and is smaller for aged eyes
than for young eyes (typically 4 mm and 8 mm for night vision). For
the central optical section less than 4.5 mm in diameter, it is
well known that spherical aberration in normal human eyes is
negligible. We describe methods for refractive correction of
presbyopia by introducing positive/negative spherical aberration or
a distribution of spherical aberrations only at the central pupil
of an eye lens less than 4.5 mm in diameter.
[0050] In one embodiment, a negative (or positive) spherical
aberration is introduced in the central optical section of an eye
less than 4.5 mm in diameter only. An example is given in FIG. 1B,
showing a wavefront map within a 6 mm zone. The wavefront shape, a
negative spherical aberration of 4 microns within a diameter of 2.8
mm, can be expressed by Zernike polynomials as -0.3
(Z12(r)+3.87*Z4(r)). Beyond the central 2.8 mm zone, the wavefront
is constant because no spherical aberration will be introduced.
[0051] FIG. 1C shows the radial distribution of refractive power
derived from the wavefront map in FIG. 1B. It is seen that the
introduced negative spherical aberration increases (12) the
refractive power from zero Diopters from pupil center to 8.2
Diopters at radius of 1.4 mm. Beyond the central zone, the
refractive power is constant (13; zero in reference to a baseline
refractive power). It must be emphasized that a baseline refractive
correction of myopia, hyperopia or astigmatism can be superimposed
to the refractive power shown in FIG IC for eyes with conventional
refractive errors.
[0052] In another embodiment, a distribution of spherical
aberrations is introduced in a central optical section of an eye
less than 4.5 mm in diameter. An example is given in FIG. 1D,
showing a wavefront map within a central optical zone of 3.6 mm in
diameter. Instead of a single spherical aberration across a central
pupil shown in FIG. 1B, this embodiment has two sections with
different distributions of spherical aberration: an inner circular
section of a diameter of 1.6 mm having a positive spherical
aberration and an outer annular section of a diameter of 3.6 mm
having a negative spherical aberration. The circular section of 1.6
mm has a positive spherical aberration about 1.34 .mu.m (or 0.1
(Z12(r)+3.87 Z4(r)) and also a focus offset of 4.0 Diopters.
Outside the circular section, the annular section has a fixed focus
power (OD) and a negative spherical aberration of about 4.3 .mu.m
(or -0.32 (Z12(r)+3.87 Z4(r)).
[0053] FIG. 1E shows the radial distribution of refractive power
derived from the wavefront map in FIG. 1D. The positive spherical
aberration in the central 1.6 mm pupil (0.8 mm in radius) causes a
gradually reduced refractive power from the pupil center with a
range of about 8 Diopters (14). The negative spherical aberration
in an annual pupil causes a gradually increased refractive power
from around 1 Diopter to around 5 Diopters (15). The wavefront map
in FIG. 1D and the refractive power FIG. 1E show the central
optical section with spherical aberrations only. Beyond the central
3.6 mm pupil, the wavefront as well as the refractive power is
constant, which is not shown for simplicity.
[0054] FIG. 2 shows the calculated MTFs of a hypothetical eye with
a refractive correction specified by the wavefront in FIG. 1B.
Three pupil sizes (2 mm, left column; 3.5 mm, middle column; and 6
mm, right column) and 3 distances (far vision at infinity, top;
intermediate vision at a focus depth of 1.0 D, middle row; and near
vision at a focus depth of 2.0 D, bottom row) are considered. Three
important aspects of refractive corrections are noticed. First, the
induced spherical aberration in the central pupil won't
significantly degrade night vision with a large pupil for distant
vision (top row and right column). Second, the induced spherical
aberration by the refraction element at the central pupil can
extend focus depth for an eye by up to 2 Diopters for pupil size
less than 3.5 mm. Third, the benefit of improved focus depth is at
a cost of degraded image quality for distance vision at a small
(top row and right column) and medium (top row, middle column)
pupil.
[0055] FIG. 3 shows the calculated MTFs of a hypothetical eye with
a refractive correction specified by the wavefront in FIG 1D. Since
increasing spherical aberration at central pupil won't
significantly degrade night vision for a large pupil for distance
vision as noticed in FIG. 2, we only calculate MTFs for three pupil
sizes within a central 3.6 mm pupil. Three pupil sizes (1.6 mm,
left column; 2.6 mm, middle column; and 3.6 mm, right column) and 4
distances (far vision at infinity, top row; intermediate vision at
a focus depth of 1.0 D, second row; near vision at a focus depth of
2.0 D, third row; and near vision at a focus depth of 3 D, bottom
row) are considered. Four aspects of refractive corrections are
noticed with this embodiment of inducing a distribution of
spherical aberrations and focus offsets in a central pupil. First,
the refractive correction provides an excellent near vision for a
pupil size between 2.6 mm and 3.6 mm. Second, the refractive
correction provides excellent far vision for a small pupil between
1.6 mm and 2.6 mm. Third, the total focus depth is as large as
3Diopters, which makes the embodiment suitable for all refractive
correction devices, including contact lenses, spectacle lenses,
IOLs, and intra-stroma refractive corneal inlay. Fourth, the
benefit of improved focus depth is at a cost of degraded image
quality for distance vision for a medium pupil size (top row and
right column).
[0056] It is seen from FIG. 1A through FIG. 3 that engineering
wavefront of an eye in the central pupil can achieve an increased
focus depth up to 3 Diopters for pupil size within a 4 mm diameter.
At night when the pupil size is larger, far vision can still be
excellent if the optics in the outer pupil region beyond the
central region maintains a focus at a far point (top row and right
column in FIG. 2).
[0057] Inducing spherical aberration or a distribution of spherical
aberrations in a central optical zone less than a 4.5 mm in
diameter (FIG. 1B and FIG. 1D) for refractive treatments of
presbyopia can be applied to a host of ophthalmic devices or
procedures, including laser vision corrections, contact lenses,
intraocular lenses, and refractive corneal inlays.
[0058] The wavefront maps in FIG. 1B and FIG. 1D can be obtained by
superimposing the refractive power shown in FIG. 1C and FIG. 1E to
a baseline refractive correction of myopia, hyperopia, or
astigmatism, or equivalently by modifying optical path difference
of a conventional lens according to a distribution of FIG. 1B and
FIG. 1D.
[0059] For the procedure of laser vision correction (refractive
correction by removing corneal tissues using laser energy), the
wavefront maps in FIG. 1B and FIG. 1D can be obtained by modifying
a baseline ablation profile for myopia, hyperopia, and astigmatism.
The change in the ablation profile equals to t0-W(x,y)/(nc-1),
where t0 is a constant thickness, W(x,y) is wavefront map
(distribution), and nc is the refractive index of the cornea.
Correction using a negative lens in conventional refractive
correction must be implemented by removing a positive lens from a
corneal for a laser vision correction.
[0060] For refractive corneal inlays that achieve refractive
correction by altering corneal curvature, the wavefront maps like
FIG. 1B and FIG. 1D can be obtained by varying thickness of an
inlay according to W(x,y)/(ni-1), where W(x,y) is the desired
wavefront map and ni is the refractive index of the corneal inlay.
W(x,y) can include a baseline of constant phase delay.
[0061] For contact lenses or spectacle lenses positioned outside
the cornea of an eye, the wavefront maps like FIG. 1B and FIG. 1D
can be obtained by superimposing the refractive power shown in FIG.
1C and FIG. 1E to a baseline refractive correction or to a constant
phase delay across a lens.
[0062] For intra-ocular lenses or corneal inlays that do not alter
curvature of optical surface of an eye, the wavefront maps like
FIG. 1B and FIG. 1D can be obtained by a variation of thickness to
the baseline lenses according to W(x,y)/(nL-n0), where W(x,y) is
the wavefront map and nL is the refractive index of IOLs or corneal
inlay while n0 is the refractive index of cornea or the refractive
index of the aqueous humor or vitreous body in the eye.
[0063] We have described a number of ophthalmic devices for
refractive correction of presbyopia based on the methods of
introducing spherical aberration or a distribution of spherical
aberrations at the central pupil in an eye. Exemplary ophthalmic
devices can be found in the sections hereafter. [0064] (a)
Refractive corneal inlays for refractive treatments of
presbyopia
[0065] FIG. 4A shows a refractive corneal inlay for refractive
correction of presbyopia in accordance with the present invention.
The refractive device 40 comprises an optic of a diameter R between
1.5 mm and 4 mm, and has a radial distribution of refractive power
in a range more than 4 Diopters across the optic.
[0066] In one embodiment as shown in FIG. 4B, the lens has the
least refractive power in the middle (.phi.1, and a gradually
increased refractive power for an increased radial distance, and a
radial power range (.phi.2-.phi.1) of more than 4 Diopters and less
than 12 Diopters. As an example, the lens in FIG. 4A has a diameter
of 2.8 mm with a radial distribution of refractive power 41a same
as 12 in FIG. 1B, and .phi.1 and .phi.2 are 0 Diopter and 8.2
Diopters, respectively. When such a lens is implanted into the
central optics of an eye, it can create a wavefront map like the
one shown in FIG. 1B because the implanted lens induces a negative
spherical aberration in the central optical zone and does not alter
refraction of an eye beyond the lens zone. Increasing focus depth
of an eye for refractive correction of presbyopia can be seen in
FIG. 2 for 3 pupil sizes at 3 different focus positions.
[0067] In another embodiment as shown in FIG. 4C, the lens has the
highest refractive power in the middle (.phi.1), and a gradually
reduced refractive power for an increased radial distance, and a
radial power range (.phi.2-.phi.1) of more than 4 Diopters and less
than 12 Diopters. As an example, the lens in FIG. 4A has a diameter
of 1.6 mm with a radial distribution of refractive power 41b same
as 14 in FIG. 1E, and .phi.1 and .phi.2 are 4 Diopter and -4.2
Diopters, respectively. When such a lens is implanted into the
central optics of an eye, it creates a positive spherical
aberration about 1 microns and a focus offset of 4 D as described
in our copending International application with the Ser. No.
PCT/US08/81421. Aberrations induced in the central pupil of the eye
will increase focus depth of an eye by 2 to 3 Diopters for
mitigation of presbyopia.
[0068] In yet another embodiment as shown in FIG. 4D, the lens has
two radial distribution of refractive power: a first zone of
reduced refractive power 42a and a second zone of increased
refractive power 42b. As an example, the lens in FIG. 4A has a
diameter of 3.6 mm with a radial distribution of refractive power
42a same as 14 in FIG. 1E, and 42b same as 15 in FIG. 1E. When such
a lens is implanted into the central optics of an eye, it can
create a wavefront map like the one shown in FIG. 1D at the central
pupil and does not alter refraction of an eye beyond the lens zone.
Increasing focus depth of an eye for refractive correction of
presbyopia can be seen in FIG. 3 for 3 pupil sizes at 4 different
focus positions.
[0069] In still another embodiment, a corneal inlay comprises an
inner optical section of 1.5 mm to 4 mm in diameter that contains
at least one aspheric surface to induce spherical aberration or a
distribution of spherical aberrations in addition to a spherical
focus power, and an outer transparent optical section of up to 6 mm
in diameter. The corneal inlay will have a refractive power
extended across the entire corneal inlay for refractive correction
of conventional myopia, hyperopia, cylinder error, and any other
refractive errors in an eye.
[0070] It must be mentioned that the refractive correction with a
corneal inlay in FIG. 4A can also be implemented with a procedure
of laser vision correction. Instead of inserting a lens that is
described by the refractive power in FIG. 4B through FIG. 4E, a
procedure of laser vision correction will remove corneal tissues to
create a radial distribution of focus power of FIG. 4C and 4E in an
opposite sign, superimposed on to a baseline ablation profile for
myopia, hyperopia, and astigmatism. A fixed ablation thickness can
be added to the ablation profile beyond the central optical zone to
avoid an abrupt change in ablation thickness. [0071] (b) Ophthalmic
devices to be worn on or implanted into an eye for refractive
treatments of presbyopia
[0072] The refractive devices in FIG. 4A that induces spherical
aberration or a distribution of spherical aberrations only at the
central pupil of an eye can further include a periphery optical
section to cover the entire pupil of an eye. FIG. 4E shows a
schematic diagram of such an ophthalmic device 43 front view (44
side view). The device comprises a central optical section 45 (less
than 4.5 mm in diameter) that has a radial distribution of
refractive power in a range more than 4 Diopters, and an outer
section 46 that has either a constant refractive power or a
controlled spherical aberration beyond the central optical
section.
[0073] In the embodiments shown in FIG. 4F through FIG. 4H, the
central optical section (47a, 47c, and 47f) has a gradually
increased refractive power from the middle of the lens same as that
of 41a in FIG. 4b. In one embodiment shown in FIG. 4F, the outer
segment 47b does not change spherical aberration in an eye and has
a refractive power same as a baseline refractive correction. In
another embodiment shown in FIG. 4G, the outer segment 47d has a
negative focus offset from a baseline refractive correction to
optimize night vision for an eye with negative spherical aberration
at pupil periphery 47e. The negative focus offset at 47d can
improve far vision at night by shifting refractive power at pupil
periphery close to zero Diopter. In yet another the embodiment
shown in FIG. 4H, the outer segment 47g contains spherical
aberration to shift the refractive power close to zero Diopter for
increased focus depth for night vision.
[0074] In the embodiments shown in FIG. 4I through FIG. 4K, the
central optical section (48a, 48c, and 48f) has a gradually
decreased refractive power from the middle of the lens same as that
of 41b in FIG. 4c. In one embodiment shown in FIG. 4I, the outer
segment 48b does not change spherical aberration in an eye and has
a refractive power same as a baseline refractive correction. In
another embodiment shown in FIG. 4J, the outer segment 48d has a
negative focus offset from a baseline refractive correction to
optimize night vision for an eye with negative spherical aberration
at pupil periphery 48e. The negative focus offset at 48d will
improve far vision at night by shifting refractive power at pupil
periphery close to zero Diopter. In yet another embodiment shown in
FIG. 4K, the outer segment 48g contains spherical aberration to
shift the refractive power close to zero Diopter for increased
focus depth for night vision.
[0075] In the embodiments shown in FIG. 4L through FIG. 4N, the
central optical section has two distributions of refractive power:
a zone of reduced refractive power (49a, d, h) and a zone of
increased refractive power (49b, e, i) as 42a and 42b in FIG. 4d.
In the embodiment shown in FIG. 4L, the outer segment 49c does not
change spherical aberration in an eye and has a refractive power
same as a baseline refractive correction. In the embodiment shown
in FIG. 4M, the outer segment 49f has a negative focus offset from
a baseline refractive correction to optimize night vision for an
eye with negative spherical aberration at pupil periphery 49g. The
negative focus offset at 49f will improve far vision at night by
shifting refractive power at pupil periphery close to zero Diopter.
In the embodiment shown in FIG. 4N, the outer segment 49j contains
spherical aberration to shift the refractive power close to zero
Diopter for increased focus depth for night vision.
[0076] When the devices in FIG. 4A and FIG. 4e are used as a
refractive cornea inlay implanted into the corneal stroma, the
device may include tiny holes in the optic to enable proper flow of
nutrients from one side of the lens to the other side. The
materials for making a corneal inlay may include hydrogel as well
as those known in the art (see e.g., U.S. Pat. No. 5,336,261 by
Graham D. Barrett, William J. Link, and Cary J. Reich). Implanting
a refractive corneal inlay may be combined with a LASIK procedure
for patients with conventional myopia, hyperopia, and
astigmatism.
[0077] Lenses with induced spherical aberration in the central
optic will involve in manufacturing of aspheric lenses because
spherical aberration are often negligible for a small numerical
aperture. Aspheric lenses can be made in a number of methods known
in the prior art: 1) by machining a lens of aspheric surface
(surfaces) with a lathe tool, 2) by molding lenses with an aspheric
mold; 3) by an ablation or activation process using laser beams or
radiation beams.
[0078] It must be mentioned that the refractive correction for
lenses in FIG. 4F through 4N can also be implemented for laser
vision corrections by removing corneal tissues. By superimpose the
distributions of refractive power to a baseline refractive
correction, ablation profiles can easily be generated for the
corrections of not only myopia, hyperopia, astigmatism, but also
presbyopia. Materials removed from the corneal for presbyopia needs
to be equal to the t0-W(x,y)/(n-1) where t0 is a constant
thickness, W(x,y) is the spherical aberration needed for
presbyopia, and n is the refractive index of corneal. [0079] (c)
Refractive correction of presbyopia by introducing a distribution
of spherical aberrations and focus offsets at central pupil of an
eye
[0080] FIG. 5A shows a schematic diagram of yet another refractive
element 51 to be worn on or implanted in the eye for refractive
correction of presbyopia. The refractive element comprises at least
two central aspheric segments 52a and 52b that create a
distribution of spherical aberrations and focus offsets within a
zone less than 4.5 mm in diameter, and an outer optical segment 53
that extends the optic beyond the central zones and up to 50 mm in
diameter.
[0081] It must be emphasized that the refractive element may
contain not only a baseline correction of myopia, hyperopia and
astigmatism, but also a distributed spherical aberration in the
central pupil of an eye.
[0082] The central aspheric segments 52a and 52b comprise at least
two refractive surfaces, and at least one of the two refractive
surfaces in both 52a and 52b is aspheric to create spherical
aberration in a small numerical aperture within which conventional
spherical refractive surfaces will have negligible spherical
aberration.
[0083] When placed in the optical path of an eye, the refractive
element superimposes a wavefront shape like the one shown in FIG.
1D at central pupil of an eye to a baseline correction for myopia,
hyperopia and astigmatism across entire pupil of an eye if
necessary. As indicated in FIG. 3, the induced distribution of
spherical aberrations and focus offsets can achieve a focus depth
of 3 D in a pupil size within 3.6 mm without accommodation from the
crystalline lens in an eye.
[0084] The outer optical segment 53 is transparent to light wave
and has an outer diameter of 5 mm to 7 mm for implantable lenses
like Intra-Ocular Lenses (IDLs), 10 to 14 mm in diameter for
contact lenses, and up to 50 mm for spectacles.
[0085] FIG. 5B shows a schematic diagram of another refractive
element 54 to be worn on or implanted in an eye for refractive
correction of presbyopia. The refractive element comprises at least
two central aspheric segments 55a and 55b that create a
distribution of spherical aberrations and focus offsets within a
zone less than 4.5 mm in diameter, and a light attenuate section 56
outside the aspheric sections, and an outer optical segment 57 that
is extended the refractive element beyond the central zones and up
to 14 mm in diameter.
[0086] The difference between the refractive elements in FIG. 5A
and in FIG. 5B is the inclusion of the light attenuating section 56
between the central aspheric section 55b and the outer section 57.
FIG. 5C shows a distribution of refractive'power with 58a and 58b
as the two aspheric sections, light trough the shades section 58c
will be blocked or attenuated, and a zone 58d with a constant
refractive power.
[0087] The light attenuating section 56 (58c) can reduce or block
light in an annular pupil section between .about.3 mm and .about.6
mm in order to reduce or eliminate impacts of high-order
aberrations in individual eyes. Adding the light attenuating
section can make the refractive element suitable for a variety of
eyes with different high-order aberrations, and thus improve
efficiency and efficacy of a refractive procedure. [0088] II.
Refractive correction ofpresbyopia by introducing a distribution of
spherical aberrations and focus offsets across pupil of an eye
[0089] Increasing focus depth of an eye can also be achieved by a
refractive element comprising of a plurality of optical sections
with a distributed focus powers and spherical aberrations across
pupil of an eye.
[0090] FIG. 6A shows a schematic diagram of such an embodiment of a
refractive element 61 to be worn on or implanted in an eye for
refractive correction of presbyopia. The central optical section 62
has one refractive power .phi.c, and is an aspheric lens to create
spherical aberration Cc in a small numerical aperture. The diameter
of the central optical section is between 1.6 mm and 4 mm. The
outer optical section 63 has a different refractive power (.phi.o
from the central optical section, and a different spherical
aberration Co.
[0091] When the refractive element is placed in the optical path of
an eye, it introduces a distributed focus powers and spherical
aberrations across pupil of an eye on top of a refractive
correction for myopia, hyperopia, astigmatism across pupil of an
eye.
[0092] By taking into account a typical spherical aberration in a
natural eye, Liang described in the copending International
application with the Ser. No. PCT/US08/81421 a number of
embodiments for distributed focus powers and spherical aberrations
across the pupil of an eye. In one embodiment, significant negative
spherical aberration is induced in the pupil center while a
positive spherical aberration is induced at pupil periphery. In
another embodiment, significant negative spherical aberration is
induced in the pupil center while spherical aberration for a large
pupil in an individual eye is eliminated. In yet another
embodiment, positive spherical aberration is induced in the pupil
center while spherical aberration for a large pupil of an eye is
corrected. In an additional embodiment, spherical aberration is
induced in the pupil center while spherical aberration in an eye is
not altered by the correction devices. A special focus offset
between the central section and outer section is required.
[0093] The outer diameter of 61 is 5 mm to 7 mm for implantable
lenses like Intra-Ocular Lenses (IOLs), 1.5 mm to 6 mm for
refractive corneal inlays, 10 mm to 14 mm for contact lenses, and
up to 50 mm for spectacles.
[0094] FIG. 6B shows a schematic diagram of an additional
embodiment of a refractive element (64) to be worn on or implanted
in the eye for refractive correction of presbyopia. The refractive
element comprises two transparent optical sections with a
distributed focus powers and spherical aberrations, and a light
attenuating segment between the two transparent optical
sections.
[0095] The difference between the refractive elements in FIG. 6A
and in FIG. 6B is the insertion of the light attenuating section 66
between the central aspheric section 65 and outer section 67. The
light attenuating section can reduce or block light in an annular
pupil section between .about.3 mm and .about.6 mm in order to
reduce or eliminate impacts of high-order aberrations in individual
eyes. Adding the light attenuating section can make the refractive
element suitable for a variety of eyes with different high-order
aberrations, and thus improve efficiency and efficacy of a
refractive procedure. [0096] III. Refractive correction of
presbyopia by creating spherical aberration in central pupil,
bifocal in mid-pupil, and mono-focal at pupil periphery.
[0097] Refractive corrections of presbyopia can further be achieved
by mixing various design features to achieve the highest degree of
tolerance. In the pupil periphery for night vision, it is desirable
to have a single dominated focus power for far vision. In the pupil
center for outdoor vision and for day vision for eyes with small
pupil, it is desirable to have excellent far vision and acceptable
near vision, which can be achieved by inducing spherical aberration
at the central pupil. In the mid-pupil for indoor vision, it is
desirable to have excellent near vision for reading and
intermediate distance, which can be achieved by a bi-focal
structure. Another advantage of the bi-focal structure in the
mid-pupil is its insensitivity to displacement if the bi-focal lens
is achieved by a structure with an alternating powers.
[0098] FIG. 7A and FIG. 7B shows a schematic diagram and a side
view of a refractive element 71 that can be worn on or implanted
into an eye for refractive correction of presbyopia according to
the present invention. The central portion of the lens 72a and 72b
will have at least one aspheric surface to induce spherical
aberration. Three potential structures are shown with the
refractive power profiles from the lens center to the radius of the
central zone (R1) relating to positive spherical aberration in FIG.
7C, negative spherical aberration in FIG. 7D, and a distribution of
spherical aberrations in FIG. 7E.
[0099] The middle section of the lens 73a and 73b will be a bifocal
lens with a refractive power of .phi.1 and .phi.2. The preferred
structure for the bi-focal lens is to use alternating powers from
R1 to R2 shown in FIG. 7C, 7D and 7E. Depending on the preference
of the lens design, .phi.1 can be zero for a biasing to far vision
or can be a positive number like 1 D for a biased vision at
intermediate distance. .phi.2 is desired to be in the range from 1
Diopter or 4 Diopters depending on individual preference.
[0100] The outer section of lens 74a and 74b will be a mono-focal
lens. Three structures can be designed based on the spherical
aberration of an eye without the correction lens. If the eye has no
spherical aberration at the pupil periphery, the outer section can
be a mono-focal lens with a refractive power set for far vision. If
the eye has significant spherical aberration at the pupil
periphery, a bias power can be applied to the outer section for
optimized for far vision at night. It is also possible to produce a
lens with spherical aberration at the lens periphery to cancel out
the spherical aberration at eye's pupil periphery for improved
night vision.
[0101] Further devices, methods, and contemplations are provided in
our co-pending PCT application with the Ser. No. PCT/US08/81421
titled "Methods and devices for Refractive treatments of
presbyopia", which was filed Oct. 28, 2008, and which is
incorporated by reference herein.
[0102] Thus, specific embodiments and applications of treatment of
presbyopia have been disclosed. It should be apparent, however, to
those skilled in the art that many more modifications besides those
already described are possible without departing from the inventive
concepts herein. The inventive subject matter, therefore, is not to
be restricted except in the spirit of the appended claims.
Moreover, in interpreting both the specification and the claims,
all terms should be interpreted in the broadest possible manner
consistent with the context. In particular, the terms "comprises"
and "comprising" should be interpreted as referring to elements,
components, or steps in a non-exclusive manner, indicating that the
referenced elements, components, or steps may be present, or
utilized, or combined with other elements, components, or steps
that are not expressly referenced.
* * * * *