U.S. patent application number 12/239462 was filed with the patent office on 2010-04-01 for laser modification of intraocular lens.
This patent application is currently assigned to Advanced Medical Optics, inc.. Invention is credited to Jim Deacon, Leander Zickler.
Application Number | 20100082017 12/239462 |
Document ID | / |
Family ID | 41351574 |
Filed Date | 2010-04-01 |
United States Patent
Application |
20100082017 |
Kind Code |
A1 |
Zickler; Leander ; et
al. |
April 1, 2010 |
LASER MODIFICATION OF INTRAOCULAR LENS
Abstract
A system of modifying an intraocular device located within an
eye, wherein the system includes a laser assembly and a controller
coupled to the laser assembly. The laser assembly outputs a pulsed
laser beam having a pulse width between about 300 picoseconds and
about 10 femtoseconds, and the controller directs the laser
assembly to output the pulsed laser beam into the intraocular
device. One or more slip zones are formed within the intraocular
device in response thereto, and the slip zones are configured to
modify a refractive profile of the intraocular device. A method of
modifying a refractive profile of an eye having an intraocular
device implanted therein, wherein the method includes determining a
corrected refractive profile for the eye based on an initial
refractive profile, identifying one or more locations within the
intraocular device based on the corrected refractive profile, and
directing a pulsed laser beam at the locations to produce the
corrected refractive profile.
Inventors: |
Zickler; Leander; (San
Francisco, CA) ; Deacon; Jim; (Goleta, CA) |
Correspondence
Address: |
ABBOTT MEDICAL OPTICS, INC.
1700 E. ST. ANDREW PLACE
SANTA ANA
CA
92705
US
|
Assignee: |
Advanced Medical Optics,
inc.
Santa Ana
CA
|
Family ID: |
41351574 |
Appl. No.: |
12/239462 |
Filed: |
September 26, 2008 |
Current U.S.
Class: |
606/4 ;
606/107 |
Current CPC
Class: |
A61F 2/1624 20130101;
A61F 2250/0008 20130101; A61F 2002/1699 20150401; A61F 9/007
20130101; A61F 2002/1681 20130101; A61F 2/16 20130101; A61F
2250/0006 20130101; A61F 2009/00848 20130101; A61F 2009/0087
20130101; A61F 9/0017 20130101; A61F 2/1629 20130101; A61F 9/008
20130101; G02C 2202/14 20130101; A61F 9/00834 20130101; A61F
2009/0088 20130101 |
Class at
Publication: |
606/4 ;
606/107 |
International
Class: |
A61F 9/008 20060101
A61F009/008 |
Claims
1. A system for modifying an intraocular device located within an
eye, the intraocular device having a refractive property, the
system comprising: a laser assembly configured to output a pulsed
laser beam having a pulse width between about 300 picoseconds and
about 10 femtoseconds; and a controller coupled to the laser
assembly, the controller configured to direct the laser assembly to
output the pulsed laser beam into the intraocular device, the
pulsed laser beam forming one or more slip zones within the
intraocular device, the one or more slip zones configured to alter
the refractive property of the intraocular device.
2. The system of claim 1, wherein the one or more slip zones
comprise one or more voids.
3. The system of claim 1, wherein each of the one or more slip
zones comprises a first portion and a second portion adjacent to
the first portion, and wherein the first portion is displaceable
with respect to the second portion.
4. The system of claim 1, wherein the intraocular device is
re-oriented within the eye in response to the one or more slip
zones by at least one of the group consisting of a horizontal
displacement, a vertical displacement, a rotation, a tilt, a
displacement towards a cornea of the eye, and a displacement toward
a retina of the eye.
5. The system of claim 1, wherein the intraocular device comprises
an optic, and wherein the one or more slip zones are within the
optic.
6. The system of claim 1, wherein the intraocular device comprises
a support structure, and wherein the one or more slip zones are
within the support structure.
7. The system of claim 1, wherein the pulsed laser beam has a pulse
energy less than or equal to about 800 nanojoules/pulse.
8. The system of claim 1, wherein the pulsed laser beam has a pulse
width between about 300 picoseconds and about 10 femtoseconds.
9. The system of claim 1, wherein the pulsed laser beam has a
wavelength between about 400 nm to about 3000 nm.
10. The system of claim 1, wherein the intraocular device comprises
an optical element and a support element, the support element
coupled to the optical element and comprising at least one haptic;
wherein the controller is further configured to direct the laser
assembly to output the pulsed laser beam into the at least one
haptic.
11. The system of claim 10, wherein each of the at least one haptic
comprises a hinge coupling the at least one haptic to the optical
element; and wherein the controller is further configured to direct
the laser assembly to output the pulsed laser beam into the hinge
of the at least one haptic.
12. The system of claim 1, wherein the eye has a capsular bag for
containing a natural lens, wherein the intraocular lens is located
within the capsular bag, and wherein the controller is further
configured to direct the laser assembly to output the pulsed laser
beam into the capsular bag to the intraocular device.
13. A method of modifying a refractive profile of an eye, the eye
having an intraocular device implanted therein and having an
initial refractive profile, the method comprising the steps of:
determining a corrected refractive profile for the eye based on the
initial refractive profile; identifying one or more locations
within the intraocular device based on the corrected refractive
profile; and directing a pulsed laser beam at the one or more
locations to produce the corrected refractive profile.
14. The method of claim 13, wherein the intraocular device has an
initial position within the eye, and wherein the directing step
comprises directing the pulsed laser beam at the one or more
locations to re-orient the intraocular device from the initial
position to a corrected position within the eye, the corrected
position corresponding with the corrected refractive profile.
15. The method of claim 14, wherein the intraocular device is
re-oriented in response to the directed pulsed laser beam by at
least one of the group consisting of a horizontal displacement, a
vertical displacement, a rotation, a tilt, a displacement towards a
cornea of the eye, and a displacement toward a retina of the
eye.
16. The method of claim 13, wherein the intraocular device has an
initial position within the eye and a thermal threshold, and
wherein the directing step comprises heating the one or more
locations above the thermal threshold via the pulsed laser beam,
the intraocular device re-orienting from the initial position to a
corrected position within the eye based on the heating, the
corrected position corresponding with the corrected refractive
profile.
17. The method of claim 13, wherein the intraocular device has an
initial position within the eye and a viscoelasticity, and wherein
the directing step comprises modifying the viscoelasticity via the
pulsed laser beam, the intraocular device re-orienting from the
initial position to a corrected position within the eye based on
the modifying, the corrected position corresponding with the
corrected refractive profile.
18. A method of modifying a refractive profile associated with an
eye, the eye having an intraocular device located within the eye,
the method comprising the steps of: determining a corrected profile
based on the refractive profile of the eye; identifying one or more
locations within the intraocular device based on the corrected
profile; and directing a femtosecond laser beam into the
intraocular device at the one or more locations to form one or more
slip zones within the intraocular device, the one or more slip
zones configured to alter the refractive profile of the eye.
19. The method of claim 18, wherein the intraocular device
comprises a support element positioning the intraocular device in a
first position within the eye, wherein the intraocular device is
displaceable from the first position within the eye to a second
position within the eye based on the one or more slip zones, the
second position at least partially implementing the corrected
profile.
20. The method of claim 18, wherein the step of directing comprises
directing a pulsed laser beam having a pre-determined pulse energy
into the intraocular device, the pulse energy being less than or
equal to about 800 nanojoules/pulse.
21. The method of claim 18, wherein the step of directing comprises
directing a pulsed laser beam having a pre-determined pulse width
into the intraocular device, the pulse width being between about
300 picoseconds and about 10 femtoseconds.
22. The method of claim 18, wherein the step of directing comprises
directing a pulsed laser beam having a pre-determined wavelength
into the intraocular device, the wavelength being between about 400
nm to about 3000 nm.
23. The method of claim 18, wherein the intraocular device
comprises an optical element; wherein the step of directing
comprises directing the femtosecond laser beam into the optical
element to form the one or more slip zones within the optical
element.
24. The method of claim 18, wherein the eye has a capsular bag for
containing a natural lens, wherein the intraocular lens is located
within the capsular bag, and wherein the step of directing
comprises directing the femtosecond laser beam through the capsular
bag into the intraocular lens.
25. A system for modifying an intraocular device having a surface
region and one or more subsurface regions, the surface region
having a mechanical property, the system comprising: a laser
assembly configured to output a pulsed laser beam; and a processing
unit coupled to the laser assembly, the processing unit configured
to control the laser assembly to direct the pulsed laser beam at
the one or more subsurface regions, the one or more subsurface
regions being structurally altered in response to the pulsed laser
beam while maintaining the mechanical property of the surface
region.
26. The system of claim 25, wherein each of the one or more regions
comprises a first portion and a second portion adjacent to the
first portion, and wherein the first portion is translationally
displaceable with respect to the second portion in response to the
pulsed laser beam
27. The system of claim 25, wherein the intraocular device has an
accommodative capability associated therewith, and wherein the
accommodative capability is increased based on the structural
alteration of the one or more regions.
28. The system of claim 25, wherein the intraocular device
comprises at least one haptic, the at least one haptic comprising a
partially polymerized photosensitive polymeric material in the one
or more regions, and wherein the polymeric material polymerizes in
response to the pulsed laser beam.
29. The system of claim 25, wherein the intraocular device is
implanted within a capsular bag of an eye, the capsular bag having
an anterior portion, and wherein the intraocular lens is displaced
against the anterior portion of the capsular bag in response to the
structural alteration of the one or more subsurface regions.
30. A method of modifying a refractive profile associated with an
eye via an intraocular device, the intraocular device comprising an
optic and a support element, the method comprising the steps of:
implanting the optic within the eye; implanting the support element
within the eye; and directing a pulsed laser beam into both of the
support element and the optic to fuse the support element to the
optic, the intraocular device within the eye configured to modify
the refractive profile.
31. The method of claim 30, wherein the support element is
partially coupled to the optic.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to intraocular
lenses and more particularly, to systems and methods for modifying
in-situ intraocular lenses.
[0003] 2. Background
[0004] When the natural lens of the eye becomes cataractous, the
natural lens may be replaced with an intraocular lens. The natural
lens may also be replaced with an intraocular lens to correct other
visual conditions, for example, to provide accommodation or
pseudo-accommodation when presbyopia develops, which limits the
focus capability of the eye on both distant objects and near
objects. Accommodating and/or multifocal intraocular lenses may be
used to restore at least some degree of accommodative or
pseudo-accommodative ability. In general, accommodating intraocular
lenses are configured to provide focus on objects over a range of
distances (e.g., by axial displacement and/or by shape change in
response to ocular forces, such as those produced by the ciliary
muscle, zonules, and/or the capsular bag of the eye).
[0005] At times, the position of the intraocular lens within the
eye may change after the insertion procedure has been completed.
Additionally, inaccurate, pre-operative eye measurements (e.g.,
used to select the intraocular lens properties or position the same
within the eye) may require changes to the position or effective
refractive properties of the intraocular lens. U.S. Pat. No.
5,571,177 describes an intraocular lens having a fixation member
with an alterable portion structured to be altered after the
intraocular lens is placed in the eye. For example, a Nd:YAG laser
is described in U.S. Pat. No. 5,571,177 for producing a laser beam
to break the alterable portion of the fixation member. The Nd:YAG
crystal associated with this laser can typically generate a laser
beam with a pulse width no shorter than about 10 picoseconds, which
limits the type, degree, and precision of structure alteration.
[0006] it is desirable to provide improved methods and systems of
modifying the position of in-situ intraocular devices (e.g.,
intraocular lenses positioned within the eye). It is also desirable
to provide methods and systems for modifying the refractive profile
of the eye via modification of in-situ intraocular devices. The
term "refractive profile" is used herein to generally describe the
optical properties associated with an eye, which may be determined
by a variety of techniques including, by way of example and not
limitation, wavefront determination. In particular, it is desirable
to provide an ophthalmic surgical system and a method of ophthalmic
surgery for re-positioning an in-situ intraocular lens via
precision alteration of one or more support elements. It is also
desirable to provide an ophthalmic surgical system and a method of
ophthalmic surgery for assembling separately implanted components
of an in-situ intraocular device. Additionally, other desirable
features and characteristics of the present invention will become
apparent from the subsequent detailed description and the appended
claims, taken in conjunction with the accompanying drawings and the
foregoing technical field and background.
SUMMARY OF THE INVENTION
[0007] The present invention is generally directed to ophthalmic
devices, systems, and methods for modification of an in-situ
intraocular device (e.g., an intraocular lens) using a laser system
that may be directed through ocular anatomy to photoalter the
intraocular device at a desired focal point. Laser energy may be
directed into one or more portions of the intraocular device (e.g.,
at a support element or an optic of the intraocular lens) to modify
the intraocular device. One advantage is that the intraocular lens
may be altered, positionally adjusted to fine-tune a desired
refractive correction, or the like, after the intraocular lens has
been inserted or implanted. Refractive properties associated with
the cornea may also be taken into account when altering the
intraocular lens or while positionally adjusting the intraocular
lens. For example, real-time refractive analysis (e.g., provided by
a wavefront aberrometer, a topographer, or the like) of one or more
components of the eye may be concurrently used during positioning
to correlate the position of the intraocular lens with the desired
refractive correction.
[0008] In one embodiment, a system for modifying an intraocular
device located within an eye is provided. The system includes a
laser assembly and a controller coupled to the laser assembly. The
laser assembly is configured to output a pulsed laser beam having a
pulse width between about 300 picoseconds and about 10
femtoseconds. The controller is configured to direct the laser
assembly to output the pulsed laser beam into the intraocular
device. The pulsed laser beam forms one or more slip zones within
the intraocular device, and the slip zone(s) are configured to
alter a refractive property associated with the intraocular
device.
[0009] In another embodiment, a method of modifying a refractive
profile associated with an eye having an intraocular device
implanted therein is provided. The method includes determining a
corrected refractive profile based on an initial refractive profile
of the eye, identifying one or more locations within the
intraocular device based on the corrected refractive profile,
directing a pulsed laser beam at the one or more locations to
produce the corrected refractive profile.
[0010] In another embodiment, a system is provided for modifying an
intraocular device having a surface region and one or more
subsurface regions. The system includes a laser assembly configured
to output a pulsed laser beam and a processing unit coupled to the
laser assembly. The processing unit is configured to control the
laser assembly to direct the pulsed laser beam at one or more
subsurface regions of the intraocular device. The one or more
subsurface regions being structurally altered in response to the
pulsed laser beam while maintaining a mechanical property of the
surface region.
[0011] In another embodiment, a method is provided for modifying a
refractive profile associated with an eye via an intraocular
device. The method includes implanting an optic of the intraocular
device within the eye, implanting a support element of the
intraocular device within the eye, and directing a pulsed laser
beam into both of the support element and the optic to fuse the
support element to the optic. The intraocular device within the eye
configured to modify the refractive profile.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings, wherein like reference numerals refer to
similar components:
[0013] FIG. 1 is a block diagram of a system for modifying an
in-situ intraocular device in accordance with one embodiment of the
present invention;
[0014] FIG. 2 is a block diagram of an ophthalmic laser system in
accordance with one embodiment;
[0015] FIG. 3 is a schematic drawing of the human eye with the
implanted intraocular lens shown in FIG. 1;
[0016] FIG. 4 is a top sectional view of an implanted intraocular
lens illustrating a re-orientation in accordance with one
embodiment;
[0017] FIG. 5 is a top sectional view of the implanted intraocular
lens illustrating a re-orientation in accordance with another
embodiment;
[0018] FIG. 6 is a side sectional view of the implanted intraocular
lens illustrating a re-orientation in accordance with another
embodiment;
[0019] FIG. 7 is a sectional view of an intraocular lens
illustrating slip zones in accordance with one embodiment;
[0020] FIG. 8 is a front view of a display illustrating an
intraocular lens modification in accordance with one
embodiment;
[0021] FIG. 9 is a flow diagram of a method for modifying a
refractive profile of an eye having an intraocular lens implanted
therein in accordance with one embodiment; and
[0022] FIG. 10 is a flow diagram of a method modifying a refractive
profile associated with an eye having an intraocular lens implanted
therein in accordance with another embodiment.
DETAILED DESCRIPTION
[0023] The present invention generally provides systems and methods
for modifying an intraocular lens, particularly an in-situ (e.g.,
positioned within an eye) intraocular lens, although these systems
and methods can also modify intraocular lenses prior to implant or
insertion. The systems and methods are utilized to structurally
modify one or more subsurface regions within the intraocular lens
while maintaining the mechanical or structural nature (i.e., prior
to this modification) of the surface region of the intraocular
lens. In one embodiment, subsurface regions of one or more support
elements (e.g., a haptic or other support element coupled to the
optic of the intraocular lens) of the in-situ intraocular lens are
modified to adjust the position of the intraocular lens within the
eye. Laser energy (e.g., supplied by a laser system outputting a
pulsed laser beam having a pulse width within a femtosecond range)
is used to irradiate the desired subsurface regions of the in situ
intraocular lens. In another embodiment, laser energy may also be
used to irradiate subsurface regions within the optic to alter the
mechanical properties of the optic (e.g., to increase
viscoelasticity, create a plastic effect, or the like).
[0024] With these systems and methods, the mechanical or structural
properties of the optic and/or haptic (or other support element)
associated with the in-situ intraocular lens may also be
advantageously modified in a non-intrusive or minimally intrusive
manner. In one embodiment, the pulsed laser beam forms one or more
slip zones in the intraocular lens. The term "slip zone" is defined
herein to be a region of material (e.g., in the optic or support
element) configured to have one portion capable of translational
displacement with respect to an adjacent portion, such as in
response to certain movements of the capsular bag containing the
intraocular lens after implantation/insertion. As a result, the
position of the intraocular lens within the eye may be finely
adjusted in one or more directions (e.g., anteriorly, posteriorly,
rotationally, vertically, horizontally, tilted, combinations of one
or more of the foregoing, and the like). For example, the
intraocular lens may be re-oriented such that the anterior surface
of the optic abuts the anterior portion of the capsular bag. A
variety of re-orientations of an in situ intraocular lens are thus
possible. Additionally, the formation of one or more slip zones in
the optic can be used to facilitate some degree of accommodation
capability of the intraocular lens or enhance accommodation
capability that has been pre-engineered in the intraocular
lens.
[0025] The systems and methods of the present invention are well
suited for customizing (e.g., fitting or adjusting) intraocular
lenses to a particular recipient. For example, as a result of
modifying one or more subsurface regions of the intraocular lens
(e.g., a haptic), the intraocular lens may be horizontally
displaced, vertically displaced, displaced towards the cornea,
displaced towards the retina, rotated, tilted, and the like, or any
combination thereof.
[0026] While used to modify in-situ intraocular lenses, the systems
and methods of the present invention may also be used to modify
intraocular lenses prior to implantation (e.g., modify a haptic or
structure coupling the haptic to the optic or join and fix the
haptic to the optic), such as during manufacture of the intraocular
lens, customization of the intraocular lens biomechanics to
implement a refractive correction for a particular recipient,
pre-implantation/insertion assembly, and the like. Additionally,
other intraocular devices replacing the natural lens in the eye can
be modified by these systems and methods.
[0027] In one embodiment, a laser assembly outputting a
non-ultraviolet (UV), ultrashort pulsed laser beam (e.g., having a
pulse duration or pulse width as long as a few picoseconds or as
short as a few femtoseconds) is used to provide the laser energy
for subsurface modifications of the in-situ intraocular lens. This
pulsed laser beam has a wavelength permitting passage of the pulsed
laser beam through the cornea and other tissue or fluids between
the intraocular lens and the outer surface of the cornea while
minimizing or preventing energy absorption by such tissue or fluids
except at the focal point of the pulsed laser beam. The laser
assembly can be used to perform post-implant procedure adjustments
to the intraocular lens or assembly thereof following a recovery
period (e.g., for the eye to recover from the procedure). During
this recovery period, the intraocular lens may settle to a more
permanent position within the eye. The laser assembly may also be
used during the implant procedure to modify the support element(s)
of the intraocular lens from a state that is more favorable for
insertion through an inserter to a state that is better suited for
operation of the intraocular lens within the eye. By modifying a
subsurface region of the intraocular lens, the intraocular lens is
re-oriented or modified while minimizing potential leaching or
particulate production.
[0028] Referring to the drawings, a system 10 for modifying an
in-situ intraocular lens 30 is shown in FIG. 1 in accordance with
one embodiment. The system 10 is suitable for ophthalmic
applications and may be used to photoalter a variety of materials
(e.g., organic, inorganic, or a combination thereof. In one
embodiment, the system 10 includes, but is not necessarily limited
to, a laser 14 capable of generating a pulsed laser beam 18, an
energy control module 16 for varying the pulse energy of the pulsed
laser beam 18, a scanner 20 (e.g., a micro-optics scanning system),
a controller 22, a user interface 32, an imaging system 34, and
focusing optics 28 for directing the pulsed laser beam 18 from the
laser 14 into the eye 12. The controller 22 communicates with the
scanner 20 and/or focusing optics 28 to direct the focal point of
the pulsed laser beam 18. Software (e.g., instrument software, and
the like), firmware, or the like, can be executed by the controller
22 to command the actions and placement of the scanner 20 via a
motion control system, such as a closed-loop proportional integral
derivative (PID) control system. In this embodiment, the system 10
further includes a beam splitter 26 and a detector 24 coupled to
the controller 22 to provide a feedback control mechanism for the
pulsed laser beam 18. The beam splitter 26 and detector 24 may be
omitted in other embodiments, for example, with different control
mechanisms. To modify the in situ intraocular lens 30, the
controller communicates with the scanner 20 and/or focusing optics
28 to direct the focal point of the pulsed laser beam 18 into the
in situ intraocular lens 30 (i.e., sub-surface).
[0029] A variety of intraocular lenses may be implanted and
modified in-situ by the system 10 including, but not necessarily
limited to, monofocal intraocular lenses, multifocal intraocular
lenses, accommodating intraocular lenses, and the like. Some
intraocular lenses include, by way of example and not of
limitation, the ReZoom.TM. multifocal lens, the Verisyse.TM. phakic
lens, and the Tecnise.RTM. aspheric lens manufactured by Advanced
Medical Optics, Inc., the AcrySof.RTM. ReStor.RTM., AcrySof.RTM.
IQ, and AcrySof Toric intraocular lenses manufactured by Alcon,
Inc., and the Crystalens.RTM. intraocular lens manufactured by
Bausch & Lomb, Inc. Some other examples of intraocular lenses
are found in U.S. Pat. No. 5,571,177, which discloses intraocular
lenses that are specifically structured to be post-operatively
re-positioned. The system 10 modifies the intraocular lens 30 via
photoalteration of one or more desired subsurface regions of the
intraocular lens 30. Examples of photoalteration include, but are
not necessarily limited to, chemical and physical alterations,
chemical and physical breakdown, liquefaction, polymerization,
disintegration, ablation, vaporization, or the like. Localized
photoalterations can be placed at the targeted portion (i.e., in
the desired subsurface region) of the intraocular lens 30 to
provide high-precision processing. Where the pulsed laser beam 18
is directed (e.g, the focal point of the pulsed laser beam 18), the
laser energy associated with the pulsed laser beam 18 modifies the
material of the intraocular lens 30 and/or the mechanical
properties associated therewith. For example, the mechanical
properties associated with a specific component or portion of the
intraocular lens 30 can be modified to have increased/decreased
rigidity, increased/decreased viscoelasticity, increased/decreased
flexibility, and the like. In another example, an intraocular lens
with pre-stressed haptics can be treated by the system 10 to form
slip zones in the haptics, thereby at least partially relieving the
stress,
[0030] Different intraocular lenses or portions of a particular
intraocular lens can have a variety of materials, each requiring
different amounts of energy to effect a desired modification. For
example, the optic and support element (e.g., a haptic) may each
have different material compositions, and the support element may
have different material compositions within different regions
thereof (e.g., a non-homogeneous support element). The controller
22 preferably directs the energy control module 16, the scanner 20,
or a combination of both, to produce a pulsed laser beam having
sufficient energy to modify the intraocular lens material. For
example, the energy control module 16 can vary the pulse energy in
response to the controller 22 to produce the pulsed laser beam 18
with sufficient energy to modify the mechanical properties of
subsurface regions of the haptic or a hinge or other structure
coupling the haptic to the optic. Thus, the mechanical properties
associated with the haptic or optic or both can be modified via the
subsurface modifications to the intraocular lens 30. The spacing
between adjacent pulses of the pulsed laser beam 18 can be varied,
as well as the pulse repetition rate, spot size, and the like, to
provide sufficient energy.
[0031] In one embodiment, the controller 22 directs the energy
control module 16, the scanner 20, or a combination of both, to
produce the pulsed laser beam 18 with pre-determined properties
(e.g., corresponding with a specific intraocular lens or material)
to modify the intraocular lens 30. Based on the physical
characteristics of the intraocular lens to be implanted, the
controller 22 selects pre-determined values of pulse energy, pulse
width, pulse repetition rate, spot separation, or the like, or any
combination thereof, to provide the energy for modifying the
support element. For example, the specific type, brand, model,
etc., of intraocular lens to be implanted may be input via the user
interface 32. In response to this input information, one or more
look-up tables are accessed by the controller 22 to retrieve the
corresponding pre-determined values (e.g., to provide the
appropriate energy for modifying the support element of the
intraocular lens). For example, the entire intraocular lens or one
or more portions of the intraocular lens may be formed from
polymethylmethacrylate (PMMA). In this example, the look-up table
contains an exposure time, a pulse energy value, a scan pattern, or
the like, that corresponds with heating the subsurface region(s)
above the glass transition temperature (T.sub.g) associated with
PMMA to modify the support element. By heating pre-determined
subsurface regions of the support element above T.sub.g, the
support element is temporarily softened thereby allowing the
support element to be bent compressed, or otherwise altered from an
original implanted state. The look-up tables can contain different
pre-determined settings for a variety of materials, intraocular
lens type, brand, model, etc., corresponding with the composition
of the intraocular lens 30. Thus, a pulsed laser beam having the
appropriate characteristics for modifying the subsurface regions of
the intraocular lens 30 can be automatically produced by the system
10. The properties of the pulsed laser beam 18 may also be manually
modified from default values (e.g., for a customized modification)
or manually input by the operator as original operating values.
[0032] To provide the pulsed laser beam 18, the laser 14 utilizes a
chirped pulse laser amplification system in one embodiment, such as
described in U.S. Pat. No. RE37,585, for photoalteration. U.S. Pat.
Publication No. 2004/0243111 also describes other methods of
photoalteration. Other devices or systems may be used to generate
pulsed laser beams, including, by way of example and not
limitation, the FS lasers manufactured by IntraLase Corp., the
FEMTO LDV.TM. laser manufactured by Ziemer Ophthalmic Systems AG,
the FEMTEC.RTM. laser by 20/10 Perfect Vision AG, and the
VisuMax.RTM. laser manufactured by Carl Zeiss Meditec AG. For
example, non-ultraviolet (UV), ultrashort pulsed laser technology
can produce pulsed laser beams having pulse durations measured in
femtoseconds. For example, U.S. Pat. No. 5,993,438, the entire
disclosure of which is incorporated herein by reference, discloses
an intrastromal photodisruption technique for reshaping the cornea
using a non-UV, ultrashort (e.g., femtosecond pulse duration),
pulsed laser beam that propagates through corneal tissue and is
focused at a point below the surface of the cornea to photodisrupt
stromal tissue at the focal point. In the system 10, the pulsed
laser beam may be focused beyond the stromal tissue and into the
capsular bag (e.g., to modify the intraocular lens 30).
[0033] The system 10 is capable of generating the pulsed laser beam
18 with physical characteristics similar to those of the laser
beams generated by a laser system disclosed in U.S. Pat. No.
4,764,930, the entire disclosure of which is incorporated herein by
reference, U.S. Pat. No. 5,993,438, or the like. For example, the
system 10 can produce a non-UV, ultrashort pulsed laser beam for
modifying the support element of the intraocular lens 30. The
pulsed laser beam 18 preferably has laser pulses with durations as
long as a few picoseconds or as short as a few femtoseconds. For
intraocular photoalteration, the pulsed laser beam 18 has a
wavelength that permits the pulsed laser beam 18 to pass through
the cornea and the anterior chamber without absorption by either or
with insignificant absorption. The wavelength of the pulsed laser
beam 18 is generally in the range of about 3 .mu.m to about 1.9 nm,
preferably between about 400 nm to about 3000 nm, and is more
preferably about 1053 nm.
[0034] The irradiance of the pulsed laser beam 18 for accomplishing
photoalteration at the focal point is sufficient for the material
associated with the support element. Although a non-UV, ultrashort
pulsed laser beam is described in this embodiment, the laser 14 can
produce a laser beam with other wavelengths in other embodiments.
In one embodiment, the laser 14 preferably has a pulse repetition
rate of about 150 kHz, although the laser 14 may operate at other
pulse repetition rates (e.g., 30 kHz, 60 kHz, 120 kHz, and the
like).
[0035] The focusing optics 28 direct the pulsed laser beam 18
toward the eye 12 (e.g., through the cornea and on or into the
intraocular lens 30) for non-UV photoalteration of the subsurface
regions within the intraocular lens 30. The system 10 may also
include an applanation lens (not shown) to flatten the cornea prior
to scanning the pulsed laser beam 18 into the eye 12. A planar,
curved, or other shaped lens is used to contact the cornea.
[0036] The user interface 32 provides a flexible and simple
environment for the operator to interact with the system 10. In one
embodiment, the user interface 32 graphically displays (e.g., using
a flat panel display or the like) information, such as from the
instrument software controlling the operation of various components
of the system 10, and provides a visual interface between the
system 10 and the operator for inputting commands and data
associated with the various components of the system. A graphical
user interface (GUI) is preferably used with the user interface 32
employing menus, buttons, or other graphical representations that
display a variety of selectable functions to be performed by the
system 10 following selection. For example, the operator points to
an object and selects the object by clicking on the object,
touching a pre-designated region of a touch-screen displaying the
GUI, or the like. Additional items may be presented on the GUI for
operator selection, such as a button or menu item indicating an
available sub-menu (e.g., a drop-down sub-menu). The user interface
32 may also utilize one or more of a variety of input devices
including, but not necessarily limited to, a keyboard, a trackball,
a mouse, a touch-pad, a touch-sensitive screen, a joystick, a
variable focal length switch, a footswitch, and the like.
[0037] In addition to the user interface 32, the imaging system 34
displays a magnified real-time digital image of the eye 12 (e.g., a
front view) and provides an interface for viewing the eye 12,
including various structures thereof, and operator control of the
centration or alignment of the laser output with the eye 12. In one
embodiment, an alignment or centration aid is displayed by the
imaging system 34 overlaying the digital image of the eye 12. The
aid corresponds with the position of the laser output in reference
to the eye 12. As part of the photoalteration process, the output
of the laser 14 is preferably aligned with the eye 12 (e.g., the
center of the pupil, the center of the outer boundary of the iris,
and the like) and/or the intraocular lens 30. For example, the
output of the laser 14 is substantially centered with reference to
the pupil and iris of the eye 12. In another example, the output of
the laser 14 is substantially centered with reference to the optic
portion of the intraocular lens 30 (e.g., along a central optical
axis of such optic portion). Viewing the digital image displayed by
the imaging system 34, the operator can center the aid (e.g., based
on the pupil and/or the iris of the patient's eye and/or the
intraocular lens) and adjust the position of the laser output.
[0038] After alignment or centration, the system 10 directs the
pulsed laser beam 18 at the support element of the intraocular lens
30 implanted in the eye 12. Movement of the focal point of the
pulsed laser beam 18 is accomplished via the scanner 20 in response
to the controller 22. The step rate at which the focal point is
moved is referred to herein as the scan rate. The term "scan" or
"scanning" refers to the movement of the focal point of the pulsed
laser beam along a desired path or in a desired pattern. For
example, the scanner 20 can operate at scan rates between about 10
kHz and about 400 kHz, or at any other desired scan rate. Further
details of laser scanners are generally known in the art, such as
described, for example, in U.S. Pat. No. 5,549,632, the entire
disclosure of which is incorporated herein by reference.
[0039] In one embodiment, the scanner 20 utilizes a pair of
scanning mirrors or other optics (not shown) to angularly deflect
and scan the pulsed laser beam 18. For example, scanning mirrors
driven by galvanometers are employed where each of the mirrors
scans the pulsed laser beam 18 along one of two orthogonal axes. A
focusing objective (not shown), whether one lens or several lenses,
images the pulsed laser beam 18 onto a focal plane of the system
10. The focal point of the pulsed laser beam 18 is thus scanned in
two dimensions (e.g., the x-axis and the y-axis) within the focal
plane of the system 10. Scanning along the third dimension, i.e.,
moving the focal plane along an optical axis (e.g., the z-axis),
may be achieved by moving the focusing objective, or one or more
lenses within the focusing objective, along the optical axis. Any
combination of scanning along one or more of these axes may be used
to direct the focal point of the pulsed laser beam 18 into the
intraocular lens 30.
[0040] The controller 22 can access an updateable database of
scanning routines to modify the subsurface region(s) of the
intraocular lens 30. In one embodiment, each of the scanning
routines corresponds to a particular type of intraocular lens and
provides a selection of pre-programmed scanning instructions to
affect a variety of modifications. For example, for a specific
intraocular lens type, a scanning routine accounts for the lens
dimensions, material properties, surface shapes, and the like,
associated with the lens. The scanning instruction can include
pre-identified subsurface locations within the particular
intraocular lens, or sets of locations, that correspond with
increasing/decreasing flexibility of a support element (e.g., a
hinge or a haptic), increasing/decreasing viscoelasticity of a
portion of the intraocular lens, creating one or more slip zones at
pre-determined subsurface regions, or altering a variety of other
mechanical or structural properties of a desired portion of the
intraocular lens. Each of the pre-programmed scanning instructions
can be manually modified via the user interface 32 as well, such as
for customization.
[0041] For example, in one embodiment, an image of the eye
illustrating the locations of various anatomical structures of the
eye as well the intraocular lens 30 location can be displayed on a
touch-sensitive screen of the user interface 32. For a particular
intraocular lens type and desired modification, the user interface
32 displays the locations of the subsurface regions to be scanned
by the pulsed laser beam 18. The operator can modify the locations
of the subsurface regions using an input device, such as a stylus,
and drawing on the touch-sensitive screen a change from the
illustrated subsurface regions to a modified subsurface location.
In another embodiment, the operator indicates the desired
subsurface regions on the touch-sensitive screen, and the
controller 22 determines a corresponding scanning procedure for
directing the pulsed laser beam 18 at the subsurface regions.
[0042] In another embodiment, the operator can indicate a desired
mechanical movement of a portion of the intraocular lens on the
touch-sensitive screen (e.g., via a drawn arrow on the
touch-sensitive screen indicating a displacement along the
direction of the arrow). An image recognition application may be
used by the controller 22 to identify the desired mechanical
movement from the drawn arrow, and the controller 22 can then
determine and propose subsurface regions (e.g., displayed on the
user interface 32) to be scanned corresponding to the desired
mechanical movement. For example, the operator can indicate a
desired shift in position (e.g., a shift along the x- and/or
y-axis, a shift along the z-axis, a tilt, a rotation, and the like)
of the optic or intraocular lens as a whole (e.g., to establish the
proper power provided by the intraocular lens, fine tune the
refractive correction, and the like). One or more slip zones can
also be drawn or otherwise indicated by the operator on the user
interface 32 (e.g., via the touch-sensitive screen), and the
controller 22 then determines the scanning procedure to produce the
slip zones.
[0043] For further customization, the system 10 acquires detailed
information about optical aberrations to be corrected, at least in
part, using the system 10. These aberrations are determined prior
to implantation of the intraocular lens 30, at a time subsequent to
the implantation of the intraocular lens 30 (e.g., after the
settling period following implantation), after further ophthalmic
procedures (e.g., LASIK or other corneal corrections, intracorneal
modifications such as intracorneal implants, and the like) have
been performed, or concurrently with the procedure for modifying
the intraocular lens 30. Examples of such detailed information
include, but are not necessarily limited to, the desired
correction, the actual correction (e.g., measured), the
re-orientation of the intraocular lens, and the like.
[0044] The refractive power of the cornea with or without
corrections made thereto (e.g., prior ophthalmic procedures such as
flap creation, LASIK, photorefractive keratectomy (PRK), laser
assisted sub-epithelium keratomileusis (LASEK), corneal pocket
creation, corneal transplant, and the like) may be used to
determine initial refractive corrections and/or additional
corrections. Wavefront analysis techniques, made possible by
devices such as a Hartmann-Shack type sensor (not shown), can be
used to generate maps of corneal refractive power. Other wavefront
analysis techniques and sensors may also be used. The maps of
corneal refractive power, or similar refractive power information
provided by other means, such as corneal topographers, optical
coherence tomography scanners, pachymeters, and the like, can then
be used to identify and locate optical aberrations of the cornea
that require correction. Determination of the particular subsurface
regions within the intraocular lens for alteration (e.g.,
mechanical or structural alteration via the pulsed laser beam 18)
can be based on the refractive power map or other optical modeling
of the patient's eye. In one embodiment, real-time wavefront
analysis is used as a feedback mechanism for guiding the
intraocular lens modifications. This wavefront analysis may be
concurrently displayed on the user interface 32 or as a separate
image together with the image of the eye and intraocular lens to
substantially indicate the effects of the modifications in
real-time (e.g., the wavefront analysis represents in real-time the
optical effects associated with the intraocular lens modifications,
re-orientations, and the like).
[0045] FIG. 2 is a block diagram of an ophthalmic laser system 40
in accordance with one embodiment of the present invention.
Referring to FIGS. 1 and 2, the ophthalmic laser system 40
includes, but is not necessarily limited to, a laser source 42
providing a pulsed laser beam (e.g., the pulsed laser beam 18), a
beam monitoring and processing module 44, a beam delivery module 46
coupled to the beam monitoring and processing module 44, the user
interface 32, and the imaging system 34. Although described as a
single system, one or more components of the system 40 may be
self-contained separate subsystems that are coupled together to
form the system 34. The pulsed laser beam is supplied to the beam
monitoring and processing module 44 where the pulse energy, the
focal point separation, and optionally the minimum sub-surface
depth of the pulsed laser beam are controlled. For example, a beam
splitter (not shown), such as the beam splitter 26, can be used to
provide a feedback loop for the pulsed laser beam 18 to the beam
monitoring and processing module 44. The beam delivery module 46
scans the pulsed laser beam along a desired scan region (e.g., as
determined by the controller 22). In this embodiment, the
ophthalmic laser system 40 can be coupled to the eye 11 via a
patient interface 33, and the patient interface 33 may be coupled
to the ophthalmic laser system 40 at a moveable loading deck 35,
for example. The configuration of the ophthalmic laser system 40
may vary as well as the organization of the various components
and/or sub-components of the ophthalmic laser system 40. For
example, some components of the beam delivery module 46 are
incorporated with the beam monitoring and processing module 44 and
vice versa.
[0046] The user interface 32 is coupled to the beam delivery module
45, and a variety of system parameters may be input or modified by
the operator via the user interface 32 to control the beam
properties and thus produce the desired photoalteration. For
example, the user interface 32 includes a display presenting a
graphical user interface with the various system parameters and an
input device (not shown) for selecting or modifying one or more of
these parameters. The number and type of system parameters may vary
for modifying a particular intraocular lens (e.g., pulse energy,
spot size, spot shape, focal point separation, focal point depth,
scanning pattern, scanning sequence, scan rate, and the like).
While described for modifying intraocular lenses, the system 40 may
be used for a variety of other ophthalmic procedures (e.g., flap
creation, PRK, LASIK, LASEK, corneal pocket creation, corneal
transplant, corneal implant, corneal onlay, and the like), and
additional system parameters may be provided by the user interface
32 for such other procedures.
[0047] In one embodiment, the parameters are input, selected, or
modified by the operator via the user interface 32. For intraocular
lens modification, the operator is prompted via the user interface
32 with the selection of parameters. The parameters may be
displayed as default values for selective modification by the
operator. Additional parameters may also be displayed by the user
interface 32 for different procedures using the system 40.
[0048] In response to the system parameters selected or input via
the user interface 32! the beam monitoring and processing module 44
and/or the beam delivery module 46 produce a pulsed laser beam with
properties corresponding with the system parameters. In one
embodiment, the beam monitoring and processing module 44 includes,
but is not necessarily limited to, an energy attenuator 41, one or
more energy monitors 43, and an active beam positioning mirror 45.
The pulsed laser beam is directed from the laser source 42 to the
energy attenuator 41, then to the energy monitor 43, and then to
the active beam positioning mirror 45. The active beam positioning
mirror 45 directs the pulsed laser beam from the beam monitoring
and processing module 44 to the beam delivery module 46. Using the
energy attenuator 41 and energy monitor 43, the pulse energy of the
pulsed laser beam may be varied to desired values. Additionally,
the spatial separation of the focal points of the pulsed laser beam
may be varied by the beam monitoring and processing module 44. This
is particularly useful to increase the precision associated with a
desired modification of the intraocular lens 30 (e.g., to create a
slip zone within the intraocular lens with pre-determined
dimensions corresponding to a desired displacement or
actuation)
[0049] The beam delivery module 46 scans the pulsed laser beam at
the desired subsurface region of the intraocular lens 30. In one
embodiment, the beam delivery module 46 includes, but is not
necessarily limited to, a beam position monitor 47, an x-y scanner
49, a beam expander 52, one or more beam splitters 54, and a
z-scanning objective 56. The pulsed laser beam is received from the
beam monitoring and processing module 44 by the x-y scanner 49 and
directed to the beam expander 52, and the beam expander 52 directs
the pulsed laser beam to the z-scanning objective via the beam
splitter(s) 54. The z-scanning objective 56 can vary the focal
point depth of the pulsed laser beam (e.g., from the anterior
surface of the eye 12 or cornea to any depth within the eye 31 up
to and including the retinal region). For modifying the intraocular
lens 30, the z-scanning objective 56 preferably directs the focal
point of the pulsed laser beam to the depth of the intraocular lens
30 within the lens capsule bag.
[0050] Prior to initiating scanning or otherwise initiating
photoalteration of the intraocular lens 30, the eye 12 is
preferably substantially immobilized with respect to the ophthalmic
laser system 40 (e.g., the ophthalmic laser system 40 can be
coupled to the eye 12). In one embodiment, the patient interface 33
provides a surface for contacting the cornea of the patient's eye
12, which may also be used to applanate the cornea. A suction ring
assembly 53 or other device may be applied to the eye 12 to fixate
the eye prior to coupling the ophthalmic laser system 40 to the eye
(e.g., via the patient interface 33). In one embodiment, the
suction ring assembly 53 has an opening providing access to the eye
12 when coupled thereto. The imaging system 34 may be used to
facilitate the coupling of the ophthalmic laser system 40 with the
eye 12. For example, by providing a real-time image of the fixated
eye, the operator can view the eye to properly center the output of
the beam delivery module 46 (e.g., with respect to the pupil, the
iris, the pupil and the iris, any other features of the eye 12, the
intraocular lens 30, or any structure of the intraocular lens
30).
[0051] Once the ophthalmic laser system 40 is coupled to the eye
12, the imaging system 34 may be used for alignment or centration
of the laser output (e.g., the beam delivery module 46 output)
and/or applanation of the cornea using the patient interface 33. A
variety of centration and alignment devices or methods (e.g.,
two-dimension alignment, such as x- and y-axis, or three-dimension
alignment, such as x-, y-, and z-axis) may also be used with the
imaging system 34 to couple the system 40 with the eye 12. The
imaging system 34 preferably provides a real-time, magnified, high
resolution digital image of the eye 12 and includes, but is not
necessarily limited to, an image sensor 57, an imaging interface
59, and an image processor 58 coupled to the sensor 57 and the
interface 59. An image of the eye 12, as well as the intraocular
lens 30, is captured using the image sensor 57 and displayed by the
imaging interface 59. In one embodiment, a high resolution digital
camera (e.g., a high-definition digital video camera based on
charge coupled devices (CCDs) or the like) is used to capture the
image and display the image on the imaging interface 59.
[0052] Although FIG. 2 illustrates a combination of the image
sensor 57 and beam splitters 54 for capturing the image, the image
sensor 57 may be located in a variety of different positions or
operate solely or operate with additional optical elements to
directly or indirectly capture images of the eye 12. For example,
the image sensor 57 may be located substantially adjacent to the
z-scanning objective 56 to directly capture images of the eye 12.
In one embodiment, the image sensor 57 is mounted on a moveable
gantry to vary the image focal plane captured by the image sensor
57 and optically coupled with a variable aperture (not shown)
(e.g., positioned between the image sensor 57 and the eye 12) for
controlling the depth of focus and/or the amount of light sensed by
the image sensor 57. In another embodiment, at least one or more of
a focus control for varying the image focal plane captured by the
image sensor 57 and a focus depth control are incorporated into the
image sensor 57. This is useful for focusing onto an optical plane
associated with the intraocular lens 30, particularly in instances
when greater resolution is desired than associated with the depth
of focus.
[0053] The imaging interface 59 includes, but is not necessarily
limited to, an input device for operator selection of the system
parameters (e.g., associated with coupling the ophthalmic laser
system 40 with the eye 12, modification of the desired subsurface
regions of the intraocular lens 30, image control, and the like)
and a monitor displaying the real-time, magnified, high resolution
digital image of the eye 12, various structures of the eye 12, the
intraocular lens 30 implanted within the eye 12, and the like. The
input device includes one or more of a keyboard, a trackball, a
mouse, a touch-pad, a touch-sensitive screen, a joystick, a
variable focal length switch, a footswitch, and the like. In a
preferred embodiment, the imaging interface 59 includes a
touch-sensitive screen displaying a graphical user interface for
selecting the system parameters and for viewing the eye 12, the
intraocular lens 30, the alignment or centration of the laser
output with reference to the eye 12, pre-determined or selected
subsurface regions of the intraocular lens, and the like. The
graphical user interface provides a variety of buttons, icons, or
the like corresponding with different functions for selection by
the operator, and the operator selects a particular function by
touching the corresponding button displayed on the touch-sensitive
screen.
[0054] Operator control of the beam delivery module 46 alignment
with the eye 12 or intraocular lens 30, applanation of the cornea,
and/or centration is provided via the input device of the imaging
interface 59 or via a separate input device (e.g., a joystick). For
example, the operator controls the raising, lowering, or lateral
movement (two-dimensions) of the loading deck 35 with the joystick
while viewing the digital image of the eye 12 provided by the
imaging system 34. The operator can adjust the lateral position
(e.g., an x-axis position and a y-axis position) of the loading
deck 35 to align the output of the beam delivery module 46 with the
eye 12 and lower the loading deck 35 (e.g., along a z-axis) to
guide the patient interface 33 into a pre-determined position with
the suction ring 53 (e.g., coupling the beam delivery module 46
with the eye 12). An indicator may also be displayed by the imaging
interface 59 (e.g., a green light) when the beam delivery module 46
is properly coupled with the eye 12 or when an applanation surface
of the patient interface 33 contacts the cornea. The operator then
applanates the cornea by further lowering the beam delivery module
46 (e.g., the loading deck 35 and patient interface 33) using the
input device, while monitoring the degree of applanation as
indicated by the digital image of the eye 12, and discontinuing
movement of the beam delivery module 46 at a desired degree of
applanation determined by viewing the digital image of the eye
12.
[0055] In one embodiment, a centration aid is displayed as an
overlay on the digital image of the eye 12 for assisting in
centering the laser output with the eye 12 or the intraocular lens
30. The centration aid corresponds with the current position of the
laser output with reference to the eye 12 or the intraocular lens
30 (e.g., the two-dimensional position in the focal plane of the
pulsed laser beam and/or axial alignment of the pulsed laser beam
with reference to an optical axis of the eye 12 or intraocular lens
30). The operator can align or center the laser output using the
joystick, or other input device, together with the centration aid.
For example, by centering the centration aid with reference to the
image of the pupil, the iris, the intraocular lens 30, or any
combination thereof, displayed by the imaging interface 59, the
output of the beam delivery module 46 becomes centered with
reference to the pupil, the iris, both the pupil and iris, the
optic of the intraocular lens, or any structure of the intraocular
lens or the eye. Following alignment or centration, the operator
can initiate scanning and photoalteration of the desired subsurface
region(s) of the intraocular lens (e.g., within the haptic, the
optic, or both the haptic and optic).
[0056] FIG. 3 is a cross-sectional view of the human eye 12 with
the implanted intraocular lens 30, shown in FIG. 1. Light enters
from the left of FIG. 3, and passes through the cornea 62, the
anterior chamber 63, the iris 64, and enters the capsular bag 65.
The intraocular lens 30 replaces the natural lens of the eye 12.
Prior to surgery, the natural lens occupies essentially the entire
interior of the capsular bag 65. After surgery, the capsular bag 65
contains the entire intraocular lens 30, in addition to a fluid
(not shown) that occupies the remaining volume (e.g., unoccupied by
the intraocular lens 30) and equalizes the pressure within the eye
60. After passing through the intraocular lens 30, light exits a
posterior wall 66 of the capsular bag 65, passes through a
posterior chamber 67, and strikes the retina 68, which detects and
converts the light to a signal transmitted through the optic nerve
to the brain.
[0057] The intraocular lens 30 has an optic 69 with a refractive
index greater than the fluid surrounding the intraocular lens 30.
The optic 69 has an anterior surface 70 facing away from the retina
68 and a posterior surface 71 facing toward the retina 68. The
optic 69 is held in place by a positioning member 72 (e.g., a
haptic), which couples the optic 69 to the capsular bag 65. In this
embodiment, the optic 69 is suspended within the capsular bag 65 to
allow accommodative movement of the optic 69 of the intraocular
lens 30 along the optical axis, for example. In another embodiment,
the intraocular lens 30 is disposed adjacent to, and even pressed
against, the posterior wall 66, for example, to reduce cellular
growth on the optic 69. The optic 69 can also be a monofocal
intraocular lens or a multifocal intraocular lens.
[0058] A well-corrected eye typically forms an image at the retina
68. If the lens has too much or too little power, the image
generally shifts axially along the optical axis away from the
retina 68 and toward or away from the lens. Note that the power
associated with focusing on a close or near object is more than the
power associated with focusing on a distant or far object. The
difference in optical power between the farthest and nearest object
that may be brought into focus by a particular lens or lens system
is commonly referred to as an "add power" (e.g., in the case of a
multifocal intraocular lens) or a "range of accommodation" or
"accommodative range" (e.g., in the case of an accommodating
intraocular lens that responds to ciliary muscle contraction to
move and/or deform axially and thereby change the optical power of
the corresponding optic). A normal add power or accommodation is
about four (4) Diopters at the plane of the optic 69 of an
intraocular lens, although this number may be three (3) or fewer
Diopters or six (6) or more Diopters, depending on the geometry of
the particular eye.
[0059] An accommodating intraocular lens, such as those disclosed
in U.S. Patent Application Publication Number 2004/0111153 (Woods
et al.), or in U.S. patent application Ser. No. 11/618,325 (Brady
et al.) and Ser. No. 11/618,411 (Brady et al.), all of which are
herein incorporated by reference in their entirety, may be used as
the intraocular lens 30. For example, the optic 69 has a clear
aperture that is disposed about a central axis or optical axis
(OA). The optic is configured to change shape in response to an
ocular force, thereby changing the optical power of the optic by at
least about one (1) Diopter, preferably by at least two (2)
Diopters, three (3) Diopters, or four (4) Diopters. For example,
the optic may be made of a relatively soft material such as a soft
acrylic or silicone material having a modulus of less than about
100 kPa or less than about 50 kPa. As used herein, the term "ocular
force" refers to a force produced by the eye for accommodation, for
example, a force produced by the ciliary muscle, zonules, or
capsular bag of the eye. Alternatively or additionally, the optic
69 may be configured to produce an effective change in the optical
power of the optic by displacing the optic along the optical axis
OA in response to an ocular force. The positioning member 72 is
generally flexible and configured for changing the shape of the
optic 69 in response to the ocular force.
[0060] The intraocular lens 30 is generally configured to be placed
within the capsular bag of the eye and configured to be compressed
to provide near or intermediate vision and/or stretched to provide
distant vision. In another embodiment, the optic 69 may further
include a mask (not shown) having a mask profile that is imposed
on, added to, or combined with the shape of a base surface of the
optic. The mask includes a diffractive or refractive surface with a
relatively low add power in another embodiment. For example, a low
add power of less than about two (2) Diopters, or even less than
one (1) Diopter, may be used to increase the depth of focus of the
intraocular lens when in one or more states of accommodation,
thereby reducing the amount of deformation or displacement
necessary to provide a predetermined amount of accommodation. In
another embodiment, the diffractive surface is replaced with or
added to a surface profile incorporating one or more of the other
configurations discussed herein to provide extended or enhanced
depth of focus.
[0061] The ocular force applied to the intraocular lens 30 is
generally provided directly by the capsular bag into which the
intraocular lens is placed. In another embodiment, the positioning
member 72 is configured so that the ocular force used to deform the
optic 69 is provided more directly by the ciliary muscle and/or
zonules, for example, by removing the capsular bag or placing the
intraocular lens in front of the capsular bag. In any case, the
intraocular lens 30 is generally configured to provide a
predetermined amount of accommodation when the ciliary muscle
contracts and/or relaxes and with an ocular force of less than
about twenty (20) grams, less than about ten (10) grams, or even
less than about five (5) grams.
[0062] The intraocular lens 30 is configured to have a
predetermined ocular power when in a reference state, for example,
with substantially no external forces on the intraocular lens 30,
except for gravity. In some embodiments, while there is
substantially no external force on the intraocular lens 30 when in
the reference state, the intraocular lens experiences internal
forces, for example, produced between the optic 69 and the
positioning member 72 due to a pre-stress introduced during
fabrication. The optical power of the intraocular lens 30 when in
the reference state is selected to provide near vision (an
accommodative bias), distant vision (a dis-accommodative bias), or
intermediate vision.
[0063] The positioning member 72 may also be configured to
additionally translate the intraocular lens 30 along the optical
axis in the anterior direction (e.g., toward the cornea) to further
enhance the accommodative power of the intraocular lens 30. In
other embodiments, the positioning member 72 is replaced by a
positioning member particularly suited for providing accommodative
motion along the optical axis OA, for example, a positioning member
configured like or similar to those disclosed in U.S. Patent
Application Numbers 2004/0082993, 2004/0111153, or 200610253196,
all of which are herein incorporated by reference.
[0064] A diffractive or refractive multifocal lens may also be used
for the intraocular lens 30. For example, the optic 69 can have an
anterior surface with a first shape, an opposing posterior surface
with a second shape, and a multifocal element or pattern imposed
on, added to, or combined with the second shape. The first and
second surfaces together providing a base power and an add power,
and the add power generally results from an add power associated
with the multifocal element. In certain embodiments, the add power
or effective add power of the optic 69 is produced by a combined
effect of both the anterior and posterior surfaces. For example, a
mask with an add power can be combined with an add power of the
multifocal element to produce a total or effective add power of the
optic 69. Alternatively, the profile of the mask differently
affects a base power and an add power of the multifocal element to
produce an add power of the optic 410 that is higher or lower than
the power of the multifocal element alone.
[0065] In one multifocal embodiment, the anterior and posterior
surfaces are configured to produce a first focus and a second focus
when the optic 69 is placed within the eye. The first focus
corresponds to or is produced by the base power of the optic 69 and
generally provides a subject with distant vision. The second focus
corresponds or is produced by the add power of the optic 69 and
generally provides a subject with near or intermediate vision. As
used herein, the term "near vision" refers to focusing on objects
or planes that are relatively close to the subject, generally
within a range of about 25-40 cm or at a distance at which a
subject would generally place printed material for the purpose of
reading. As used herein the term "intermediate vision" refers to
focusing on objects situated approximately 40 centimeters to
approximately 1.5 meters from the eye or a spectacle plane. As used
herein, the term "distant vision" refers to focusing on objects or
planes that are relatively distant from the subject, for example,
generally at a distance that is greater than about 1 meter to about
2 meters away from the subject or at a distance of 5 to 6 meters or
greater.
[0066] The base power and the add power are generally powers of the
optic when the lens is disposed within a medium having a refractive
index similar to that of the aqueous humor of the eye, for example,
in a medium having a refractive index of or about 1.336. In other
embodiments, the reference media is different from the media of the
aqueous humor, for example, a refractive index of air or about
1.
[0067] The multifocal element can be a diffractive element in which
two or more diffractive orders are used to provide two or more
optical powers. Alternatively or additionally, the multifocal
element is a refractive multifocal, for example, as disclosed in
U.S. Pat. No. 5,225,858 or U.S. Pat. No. 6,210,005, which are
incorporated in their entirety herein. In some embodiments, the
multifocal element has a relatively low add power (e.g., less than
about or equal to 2 Diopters or less than or equal to about 1
Diopter), for example, with a diffractive pattern. In such
embodiments, the relatively low add power of the multifocal element
can be combined with a multifocal element on the anterior surface
to produce a combined add power of the optic that has a
predetermined value. In other embodiments, the multifocal element
has a relatively high add power (e.g., greater than or equal to
about 3 Diopters or greater than or equal to about 4 Diopters), for
example, so that the intraocular lens provides two or more distinct
foci when placed in the eye of a subject (e.g., to one for near
vision and another for distant vision).
[0068] The system 10, 40 may be used to modify the structure of the
intraocular lens 30 following implantation/insertion into the eye.
In one embodiment, material from the intraocular lens 30, such as
on or in the positioning member 72, is ablated or photoaltered
(e.g., by the pulsed laser beam produced by the system 10, 40). For
example, void areas within the positioning member 72 are produced
to weakened specific zones within the positioning member 72. In
general, the pulsed laser beam produced by the system 10, 40 (e.g.,
using a laser with an ultra-short pulse in the picosecond to
femtosecond range, such as an Nd:YLF laser operating at a
wavelength of about 1053 nm) does not produce heat sufficient to
impair the eye. The system 10, 40 may thus be focused to produce a
condition of laser-induced optical breakdown, which produces an
insignificant amount of heat.
[0069] In one embodiment, an accommodating intraocular lens has an
optic and a positioning member or support structure with multiple
arms, and each of the arms has a hinge area about which the arm can
pivot and provide accommodative motion of the optic. For
implantation/insertion (e.g., through a relatively narrow conduit),
the hinges may be configured with substantial stiffness to
withstand transportation through the narrow conduit. For example,
the hinges are formed of a material having a desired stiffness or
relative inflexibility. Following implantation/insertion, the
hinges are biomechanically altered by the system 10, 40 to allow a
more efficient transfer of ocular forces (e.g., from the ciliary
muscle) into axial motion of the optic. In one example, the system
10, 40 precisely directs the pulsed laser beam at the hinges to
create sub-surface slip zones, which enhance the accommodative
effect of the intraocular lens.
[0070] In another embodiment, the accommodating intraocular lens is
implanted into the eye and includes a haptic of photosensitive
polymer material that is partially polymerized. The partially
polymerized haptic is more compliant for transport through the
narrow conduit. Following implantation/insertion, the system 10, 40
can be used to direct the pulsed laser beam into the haptic to
extend polymerization of the haptic until a pre-determined
stiffness is achieved (e.g., a stiffness suited to the transfer of
energy to the intraocular lens for accommodative motion and/or
deformation of the optic).
[0071] In yet another embodiment, the intraocular lens includes an
optic and a support structure that are separately implanted into
the eye. Alternatively, the optic and support structure are
partially coupled to one another for a more compact configuration
of the intraocular lens during implantation/insertion into the eye.
Following implantation/insertion of both structures, the system 10,
40 can direct the pulsed laser beam to join or weld portions of the
optic to the support structure.
[0072] The pulsed laser beam produced by the system 10, 40 may also
be used to fit the implanted intraocular lens 30 to the capsular
bag 65 or other structure. For example, the support structure can
be weakened, expanded, or rearranged to fit the intraocular lens to
the capsular bag. This is particularly useful for enhancing or
optimizing an accommodative effect of a suitably configured
intraocular lens.
[0073] As previously mentioned, a variety of re-orientations (e.g.,
displacements horizontally, vertically, diagonally, rotationally,
non-linearly, combinations of one or more of the foregoing, and the
like) are possible using the system 10, 40. FIG. 4 is a top
sectional view of an implanted intraocular lens 80 illustrating a
re-orientation in accordance with one embodiment. FIG. 5 is a top
sectional view of the implanted intraocular lens 80 illustrating a
re-orientation in accordance with another embodiment. FIG. 6 is a
side sectional view of the implanted intraocular lens 80
illustrating a re-orientation in accordance with another
embodiment. The intraocular lens 80 is implanted within the
capsular bag 82 of an eye, such as the eye 12 shown in FIGS. 1 and
2. In these embodiments, the intraocular lens 80 is re-oriented
from an initial position (in broken line) to the final position
illustrated in FIGS. 4-6. The final position is substantially
aligned (e.g., centered) with reference to an optical axis, A, of
the eye. The system 10, 40 (FIGS. 1 and 2) may be used for these
re-orientations as well as for a variety of other re-orientations
of an in situ intraocular lens. As shown in FIG. 4, the intraocular
lens 80 is translated along the horizontal axis or a y-axis to
center the intraocular lens 80 about the optical axis or another
selected axis. As shown in FIG. 5, the intraocular lens 80 is
rotationally re-oriented about the optical axis. As shown in FIG.
6, the intraocular lens 80 is re-oriented along the optical axis or
a z-axis to vault the intraocular lens 80 against the posterior
portion 84 of the capsular bag 82.
[0074] Although the final position of the intraocular lens 80 is
substantially aligned with reference to the optical axis, the
intraocular lens 80 may be aligned based on other references,
including the pupil or macula, for example. Using real-time
wavefront analysis or other refractive analysis techniques of the
eye for feedback input, the system 10, 40 can also indicate (e.g.,
via the user interface 32 shown in FIG. 1) the relative change to
the refractive profile of the eye during re-orientation as well as
subsequent to re-orientation of the intraocular lens 80.
[0075] FIG. 7 is a sectional view of the intraocular lens 80
illustrating slip zones 90, 92 in accordance with one embodiment.
The intraocular lens 80 includes an optic portion 86 and a haptic
portion 88, and the slip zones 90, 92 are located in pre-determined
sub-surface regions of the intraocular lens 80 to induce a
modification to the mechanical or structural characteristics
thereof. The system 10, 40 (FIGS. 1 and 2, respectively) may be
used to form the slip zones 90, 92. In this embodiment, some slip
zones 92 are formed in the haptic portion 88 or in a hinge coupling
the haptic portion 88 to the optic portion 86, and some slip zones
90 are formed in the optic portion 86. With the slip zones 92, the
flexibility of the haptic portion 88 as a whole may be temporarily
or permanently altered, and this feature can facilitate a
re-orientation of the intraocular lens 80. For example, the slip
zones 92 can increase flexibility of the haptic portion 88 to allow
displacement of the position of the optic portion 86 (e.g.,
anterior or posterior vaulting, rotation, tilt, linear shift, and
the like) and to more precisely or more accurately implement the
refractive correction provided by the intraocular lens 80. The
intraocular lens 80 may also be engineered with various structural
elements that have been pre-determined to facilitate a desired
re-orientation (e.g., along a specific displacement vector). In
another example, the slip zones 92 are formed prior to implantation
(e.g., during manufacture or finishing of the intraocular lens 80)
to increase flexibility of the haptic portion 88 and ease folding
or insertion of the intraocular lens 80.
[0076] The slip zones 90 formed in the optic portion 86 may also
assist in re-orienting the intraocular lens 80. Alternatively, the
slip zones 90 can impart or diminish mechanical or structural
properties associated with the optic portion 86. For example, some
degree of accommodation can be provided to the optic portion 86 by
the slip zones 90 as one portion of a slip zone displaces with
respect to the other portion (e.g., a slide motion). The location
of the slip zones 90, 92 may be pre-determined based on known
properties of the intraocular lens 80, the refractive profile of
the eye, and the like, displayed as defaults, altered and/or
indicated by the operator, such via a user interface.
[0077] FIG. 8 is a front view of a user interface 94 illustrating
an intraocular lens re-orientation in accordance with one
embodiment. The user interface 94 has a touch-sensitive screen 95
displaying a real-time image of an implanted intraocular lens 96
and provides a variety of system controls (e.g., selectable
touch-sensitive buttons). Other representations of the implanted
intraocular lens 96 may be displayed by the user interface 94
(e.g., based on real-time wavefront analysis, historical data of
the patient's eye, and the like). The intraocular lens 96 is
implanted in the capsular bag 98 of a patient's eye. In this
embodiment, the operator has indicated a desired re-orientation of
the intraocular lens 96 via a directional symbol 99 (e.g., an
arrow). For example, the operator can use a stylus to draw the
directional symbol 99 on the user interface 94. The placement of
the directional symbol 99 as well as other characteristics of the
directional symbol 99 (e.g., the length, shape, and the like) is
detected by an image recognition application, and proposed
modifications to the intraocular lens 96 can be determined and
displayed by the user interface 94 to the operator.
[0078] The user interface 94 includes a "Back" button configured to
return the displayed menu of system controls to a prior displayed
menu, an "Auto-position" button configured to indicate a
pre-determined re-orientation of the intraocular lens 96 on the
displayed image (e.g., as an overlay image), a "Linear Shift"
button configured to interpret the directional symbol 99 as a
linear displacement, a "Rotate" button configured to interpret the
directional symbol 99 as a rotational displacement, a "Manual"
button configured to indicate a direct correlation of the
directional symbol 99 with the desired displacement, a "Depth +"
button configured to increase the focal plane depth of the
displayed image, a "Depth -" button configured to decrease the
focal plane depth of the displayed image, a "View Adjust" button
configured to recall a menu of different views corresponding to the
displayed image, a "Magnify" slide button configured to vary the
displayed image magnification, and a "Fine/Coarse" slide button
configured to vary the magnitude of displacement indicated by the
directional symbol 99. A variety of other functions or combinations
of some of the foregoing system controls may be provided by the
user interface 94 via one or more of the same or different input
mechanisms.
[0079] Additionally, the user interface displays a centration aid
93 as an overlay image, which may assist in determining the
re-orientation of the intraocular lens 96 (e.g., with respect to a
pre-determined reference). Following the selection or indication of
the desired re-orientation, a suitable scan pattern is determined
to direct the pulsed laser beam at the corresponding sub-surface
regions of the intraocular lens 96.
[0080] FIG. 9 is a flow diagram of a method 100 for modifying a
refractive profile of an eye having an intraocular device implanted
therein in accordance with one embodiment. A corrected refractive
profile is determined based on an initial refractive profile of an
eye, as indicated at 105. Referring to FIGS. 1 and 2, for example,
the initial or starting refractive profile of the eye 12 can be
determined using wavefront analysis techniques prior to
modification of the intraocular lens 30. In one embodiment, the
intraocular lens 30 is determined to be in an initial position
within the eye 12. A corrected position of the intraocular lens 30
can be determined (e.g., by modeling in situ mechanical behavior of
the intraocular lens 30 using known mechanical or structural
characteristics of the intraocular lens 30, real-time or historical
wavefront analysis of the eye 12 with the implanted intraocular
lens 30, and the like) based on a re-orientation of the intraocular
lens 30 to produce the corrected refractive profile.
[0081] One or more locations within the intraocular device are
identified based on the corrected refractive profile, as indicated
at 110. For example, the controller 22 determines which sub-surface
regions of the intraocular lens 30 (e.g., within one or more
haptics or support elements, within the optic, or within both) are
to be irradiated with the pulsed laser beam 18 to produce the
corresponding re-orientation of the intraocular lens 30 (resulting
in the corrected refractive profile). The locations within the
intraocular device may also be determined by the operator or
through a combination of controller 22 and operator input.
[0082] A pulsed laser beam is directed at the one or more locations
within the intraocular device to produce the corrected refractive
profile, as indicated at 115. In one embodiment, the intraocular
device is displaced from the initial position within the eye (e.g.,
pre-modification) to a corrected position within the eye based on
directing the femtosecond laser beam at the one or more locations.
Referring to FIGS. 4-6, examples are shown of displacing the
intraocular lens 80 from the initial position (shown in broken
line) to the corrected position. The corrected position of the
intraocular device within the eye at least partially implements the
corrected refractive profile.
[0083] The pulsed laser beam 18 may have a pre-determined pulse
energy less than or equal to about 800 nanojoules/pulse, a
pre-determined pulse width between about 300 picoseconds and about
10 femtoseconds, and/or a pre-determined wavelength between about
400 nm to about 3000 nm. Typically, the intraocular lens 30 is
located within the capsular bag (e.g., following
implantation/insertion and prior to modification). The intraocular
device 30, or portions thereof, may have a pre-determined thermal
threshold (e.g., a glass transition temperature) or a
pre-determined viscoelasticity. In one example, the pulsed laser
beam 18 is directed into the capsular bag and into the intraocular
lens 30 at the sub-surface regions (e.g., by scanning) to heat
these sub-surface regions above the thermal threshold. The
mechanical or structural characteristic of the intraocular lens 30
is thus modified by such heating, and the intraocular lens 30 may
then be re-oriented within the eye 12 (edgy, horizontally
displaced, vertically displaced, displaced towards the cornea,
displaced towards the retina, rotated, tilted, and the like, or any
combination thereof). In another example, referring to FIG. 7, one
or more slip zones 90, 92 may be formed at the sub-surface regions
via the pulsed laser beam 18 to re-orient the intraocular lens 30
to the corrected position. The slip zones 90, 92 allow weakening,
expansion, or rearrangement of the intraocular lens 30 to fit to
the capsular bag, for example. This is particularly useful for
enhancing or optimizing an accommodative effect of a suitably
configured intraocular lens.
[0084] In addition to modifying or re-orienting in situ intraocular
lenses, FIG. 10 is a flow diagram of a method 200 for modifying a
refractive profile associated with an eye in accordance with
another embodiment. An optic is implanted within the eye, as
indicated at 205. A support element (e.g., a haptic) is implanted
within the eye, as indicated at 210. A pulsed laser beam is
directed into the support element and the optic to fuse the support
element to the optic, as indicated at 215. The resulting
intraocular device within the eye (i.e., with the support element
fused to the optic) modifies the refractive profile of the eye. In
one embodiment, the support element may be partially coupled to the
optic and implanted in this arrangement (e.g., to ease the
insertion or implantation process). The intraocular lens may then
be assembled in situ by fusing the support element to the optic.
The pulsed laser beam may also fix the support element to the optic
by other techniques, such as initializing polymerization and the
like.
[0085] Thus, the systems 10, 40 can precisely modify and/or
re-orient in situ intraocular lenses while minimizing particulate
generation during this process. While embodiments of this invention
have been shown and described, it will be apparent to those skilled
in the art that many more modifications are possible without
departing from the inventive concepts herein.
* * * * *