U.S. patent number RE40,420 [Application Number 11/411,209] was granted by the patent office on 2008-07-01 for method and device for treating opaqueness and/or hardening of a closed eye.
This patent grant is currently assigned to Carl Zeiss Meditec AG. Invention is credited to Manfred Dick, Eckhard Schroeder.
United States Patent |
RE40,420 |
Dick , et al. |
July 1, 2008 |
Method and device for treating opaqueness and/or hardening of a
closed eye
Abstract
The present invention relates to a method and a device for
treating opacities and/or hardenings of an unopened eye. It is a
specific advantage of the solution according to the invention that
the treamtment of the inner region of the eye is possible without
the need to introduce a surgical instrument into the eye.
Inventors: |
Dick; Manfred (Gefell,
DE), Schroeder; Eckhard (Eckental, DE) |
Assignee: |
Carl Zeiss Meditec AG (Jena,
DE)
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Family
ID: |
7919824 |
Appl.
No.: |
11/411,209 |
Filed: |
August 25, 2000 |
PCT
Filed: |
August 25, 2000 |
PCT No.: |
PCT/EP00/08308 |
371(c)(1),(2),(4) Date: |
February 25, 2002 |
PCT
Pub. No.: |
WO01/13838 |
PCT
Pub. Date: |
March 01, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
10069607 |
Feb 25, 2002 |
06726679 |
Apr 27, 2004 |
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Foreign Application Priority Data
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Aug 26, 1999 [DE] |
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199 40 712 |
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Current U.S.
Class: |
606/4; 128/898;
606/6 |
Current CPC
Class: |
A61F
9/008 (20130101); A61F 9/00825 (20130101); A61F
9/00838 (20130101); A61F 9/0084 (20130101); A61B
2017/00154 (20130101); A61B 2017/00172 (20130101); A61F
9/00736 (20130101); A61B 90/20 (20160201); A61F
9/009 (20130101); A61F 2009/0087 (20130101); A61F
2009/00872 (20130101); A61F 2009/00874 (20130101); A61F
2009/00887 (20130101); A61F 2009/00895 (20130101) |
Current International
Class: |
A61F
9/008 (20060101) |
Field of
Search: |
;128/898 ;606/4-6 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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197 18 139 |
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Nov 1998 |
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DE |
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19718139 |
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Nov 1998 |
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DE |
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09 03 133 |
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Mar 1999 |
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EP |
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WO 8707165 |
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Dec 1987 |
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WO |
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WO 9308677 |
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May 1993 |
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WO |
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WO 93/08677 |
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May 1993 |
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WO |
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9308677 |
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May 1993 |
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WO |
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9425107 |
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Nov 1994 |
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WO |
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WO 94/25107 |
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Nov 1994 |
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WO |
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Primary Examiner: Johnson, III; Henry M.
Attorney, Agent or Firm: Darby & Darby
Claims
What is claimed is:
1. A method for noninvasively dissolving opacities and/or
hardenings of an eye comprising: .[.dissolving.]. .Iadd.directing a
plurality of ultrashort pulses of a laser on an opacity and/or
hardening of the eye so as to dissolve .Iaddend.at least one of
.[.an.]. .Iadd.the .Iaddend.opacity and .[.a.]. .Iadd.the
.Iaddend.hardening .[.via a.]. .Iadd., wherein the ultrashort
pulses have a duration of less than 10 ps and the
.Iaddend.plurality of ultrashort pulses .[.of a laser defining.].
.Iadd.define .Iaddend.a pulse train having a duration of less than
1 s.
2. The method as recited in claim 1, wherein the duration .Iadd.of
the pulse train .Iaddend.is less than 0.1 s.
3. The method as recited in claim 1, wherein the pulse train is
emitted repeatedly.
4. The method as recited in claim 3, wherein a repetition frequency
of the .Iadd.pulses in the .Iaddend.repeated pulse train is in the
kHz range.
5. The method as recited in claim 1, further comprising selecting a
laser radiation of a wavelength which has at least one of a higher
absorption and a lower reflection for the at least one of the
opacity and the hardening than for a remaining part of the eye.
6. The method as recited in claim 1, further comprising aligning
the ultrashort pulses so that energy densities which dissolve the
at least one of the opacities and hardenings occur within the at
least one of the opacity and the hardening while, at the same time,
no damage is caused to tissue in other regions of the eye.
7. The method as recited in claim 6, wherein the alignment of the
ultrashort pulses takes place via at least one of a deflection
device, focusing optics and a contact glass.
8. The method as recited in claim 1, further comprising acquiring
data on the at least one of the opacity and the hardening by
measuring reflected radiation of low energy prior to actual
treatment, and selecting the alignment and the energy of the
ultrashort pulses as a function of the acquired data.
9. A method for operating a device according to claim .[.1.].
.Iadd.14.Iaddend., the method comprising: using the device
subsequent to an excimer laser treatment in the case of haze
formation in the cornea.
10. The method for operating a device according to claim .[.1.].
.Iadd.14.Iaddend., the method comprising using the device to treat
cloudings of a lens nucleus in the case of incipient cataract.
11. The method for operating a device according to claim 1, the
method comprising using the device to treat .[.impurties.].
.Iadd.impurities .Iaddend.in a vitreous body in a visual field.
.[.12. A method for noninvasively treating the presbyopia of an eye
comprising using the method of claim 1, and producing blisters in a
lens of the eye, the blisters filling with liquid..].
.[.13. The method as recited in claim 12, wherein the blisters are
produced as blister fields in the lens..].
14. A device for noninvasively treating opacities and/or hardenings
of an eye comprising: a laser having a wavelength in a range of
from 350 nm to 1300 nm; and a device for generating a pulse train
of ultrashort pulses .Iadd.having a pulse duration of less than 10
ps .Iaddend.from the laser, the pulse train having a duration of
less than 1 s, an aligning device for aligning the ultrashort
pulses, the aligning device including one of a deflection device,
focusing optics, and a contact glass, and a control device
controlling the aligning device for aligning the ultrashort pulses
as a function of data on at least one of the opacity and the
hardening.
15. The device as recited in claim 14, wherein the duration of the
pulse train is less than 0.1 s.
16. The device as recited in claim 14, wherein the device for
generating a pulse train generates pulse trains with a repetition
frequency.
17. The device as recited in claim 16, wherein the device for
generating pulse trains with a repetition frequency generates pulse
trains in the kHz range.
18. The device as recited in claim 14, further comprising a device
for generating a laser radiation having a wavelength which has at
least one of a higher absorption and a lower reflection for the at
least one of the opacity and the hardening than for remaining parts
of the eye.
19. The device as recited in claim 14, wherein the wavelength of
the laser is in the range of from 780 nm to 1060 nm.
20. A method for noninvasively dissolving opacities and/or
hardenings of an eye comprising: .[.dissolving.]. .Iadd.directing a
plurality of ultrashort pulses of a laser on an opacity and/or
hardening of the eye so as to dissolve .Iaddend.at least one of
.[.an.]. .Iadd.the .Iaddend.opacity and .[.a.]. .Iadd.the
.Iaddend.hardening .[.via a.]. .Iadd., wherein the
.Iaddend.plurality of ultrashort pulses .[.of a laser defining.].
.Iadd.have a duration of less than 10 ps and .Iaddend.a pulse
train, wherein the pulse train is emitted repeatedly and wherein a
repetition frequency of the .Iadd.pulses in the .Iaddend.repeated
pulse train is in the kHz range.
21. The method as recited in claim 20 wherein the method is used
for treating a haze formation subsequent to an excimer laser
treatment.
22. The method as recited in claim 20 wherein the method is used
for treating cloudings of a lens nucleus in the case of an
incipient cataract.
23. The method as recited in claim 20 wherein the method is used
for treating impurities in a vitreous body in a visual field.
24. A method for noninvasively treating the presbyopia of an eye
comprising: .[.dissolving.]. .Iadd.directing a plurality of
ultrashort pulses of a laser on an opacity and/or hardening of the
eye so as to dissolve .Iaddend.at least one of .[.an.]. .Iadd.the
.Iaddend.opacity and .[.a.]. .Iadd.the .Iaddend.hardening .[.via
a.]. .Iadd., wherein the .Iaddend.plurality of ultrashort pulses
.[.of a laser defining.]. .Iadd.have a duration of less than 10 ps
and define .Iaddend.a pulse train.Iadd., and wherein the directing
is performed .Iaddend.so as to produce blisters as blister fields
in a lens of the eye, the blisters filling with liquid.
.Iadd.25. The method as recited in claim 24, wherein the blister
fields are produced inside of the lens..Iaddend.
.Iadd.26. The method as recited in claim 25, wherein the blister
fields are symmetrically arranged..Iaddend.
.Iadd.27. A method for noninvasively treating the presbyopia of an
eye comprising: directing a plurality of ultrashort pulses of a
laser on an opacity and/or hardening of the eye so as to dissolve
at least one of the opacity and the hardening, wherein the
plurality of ultrashort pulses have a duration of less than 10 ps
and define a pulse train, and wherein the directing is performed so
as to produce blisters in a lens of the eye, and results in an
increasing flexibility of the lens..Iaddend.
.Iadd.28. The method as recited in claim 27, wherein the directing
is performed so as to produce the blisters inside of the
lens..Iaddend.
.Iadd.29. The method as recited in claim 28, wherein the directing
is performed so as to produce the blisters in a symmetrically
arrangement..Iaddend.
.Iadd.30. The method as recited in claim 27 wherein the ultrashort
pulses have a duration in the fs range..Iaddend.
.Iadd.31. A method for noninvasively treating the presbyopia of an
eye comprising: directing a plurality of ultrashort pulses of a
laser having a duration of less than 10 ps to an inside of a lens
of the eye so as to dissolve at least one of an opacity and a
hardening in the lens, wherein the directing results in an
increased flexibility of the lens..Iaddend.
.Iadd.32. The method as recited in claim 31, wherein the ultrashort
pulses have a duration in the fs range..Iaddend.
.Iadd.33. The method as recited in claim 31, wherein the ultrashort
pulses have a duration in the ps range..Iaddend.
.Iadd.34. The method as recited in claim 31, wherein the ultrashort
pulses have a duration from 10 ps to 10 fs..Iaddend.
.Iadd.35. The method as recited in claim 31, further comprising
amplifying the ultrashort pulses..Iaddend.
.Iadd.36. The method as recited in claim 35, wherein the
amplification is performed using the Chirped Pulse Amplification
Method..Iaddend.
.Iadd.37. The method as recited in claim 31, wherein the directing
of the ultrashort pulses includes aligning the ultrashort pulses
using at least one of a deflection device, focusing optics and a
contact glass..Iaddend.
.Iadd.38. The method as recited in claim 37, wherein the aligning,
of the ultrashort pulses includes preselecting an energy, density
of the ultrashort pulses at the inside of the lens..Iaddend.
.Iadd.39. A device for noninvasively treating the presbyopia of an
eye comprising: a laser configured to emit ultrashort pulses having
a pulse duration in the fs range in a pulse train having a duration
of less than 5 seconds; an aligning device for aligning the
ultrashort pulses, the aligning device including one of a
deflection device, focusing optics, and a contact glass; and a
control device controlling the aligning device for aligning the
ultrashort pulses such that a focus of the ultrashort pulses comes
to rest in an inside of the lens..Iaddend.
.Iadd.40. The device as recited in claim 39, wherein the laser is
configured to emit the ultrashort pulses in a pulse train having a
duration of less than 2 seconds..Iaddend.
.Iadd.41. The device as recited in claim 40, wherein the laser is
configured to emit the ultrashort pulses in a pulse train having a
duration of less than 0.1 seconds..Iaddend.
.Iadd.42. The method as recited in claim 41, wherein the ultrashort
pulses have a duration of approximately 300 fs..Iaddend.
.Iadd.43. The method as recited in claim 1, wherein the ultrashort
pulses have a duration of from 10 ps to 10 fs..Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a method and a device for treating
opacities and/or hardenings of an unopened eye. Specifically, the
present invention relates to a laser system and a method for
cleaning, in particular, the ageing human eye from gray hazes in
the cornea, the lens or the vitreous body to restore transparency
in the eye.
In ophthalmology, it is known that, in particular in the ageing
eye, opacities develop in the lens (cataract) or in the vitreous
body or the cornea. At the advanced stage, the treatment is
presently limited to replacing the lens with a plastic lens during
a cataract surgery, replacing the vitreous body with silicone oil
by vitrectomy, or also to transplanting the cornea. It is known to
carry out the surgery of the cataract and the vitrectomy of the
vitreous body using a laser. During a surgery, the laser beam is in
both cases led directly to the tissue to be treated. A proven
efficient laser is, in particular, the Er:YAG laser having the
emission wavelength of 2.94 .mu.m whose radiation is strongly
absorbed by water. For conveying the laser radiation, cannulas with
optical waveguides are led up to the location of treatment.
Although cannulas having diameters of approximately 1 mm are
manufacturable now, the necessity of the surgical intervention
remains. A device for carrying out a laser phacoemulsification is
described, for example, in German Patent 19718139.
Also known are surgical techniques in the case of which the eye is
not opened but the laser light is guided into the eye via the
normal path of the visual process. These techniques include the
possibility of attaining an optical disruption inside of the cornea
by focusing fs laser pulses (300 fs, 1 .mu.l, 780 nm), resulting in
the formation of blisters. By folding open a lamella, it is
possible to prepare an intrastromal lenticle whose removal brings
about a refractive correction. It is known, moreover, that the gray
after-cataract membrane can be disruptively removed with the aid of
ns pulses of a Q-switched Nd:YAG laser.
In known methods heretofore, apart from medicamentous methods, it
was not possible to treat the clouded regions already at the
initial stage. Thus, the known laser techniques are not suitable
for removing the clouded regions in the eye without opening the
eye. Therefore, it is an object of the present invention to provide
a method and a device which make it possible to dissolve clouded
regions in the eye.
A further phenomenon which occurs in old age is presbyopia. One
reason for this lies in the hardening of the lens, which can occur,
for example, due to deposit of substances. Apart from the
utilization of spectacles, photorefractive keratectomy (PRK) has
often been used recently for correcting the visual defect. Removal
of the hardening itself has not been possible in known methods
heretofore. Therefore, it is a further object of the present
invention to provide a device with which the lens' ability to
contract is increased again.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a
method and a device which make it possible to dissolve opacities
and/or hardenings of an eye.
This objective is achieved, in particular, by a method for
dissolving opacities and/or hardenings of an unopened eye in
connection with which the opacities and/or hardenings are dissolved
via at least one ultrashort pulse of a laser without opening the
eye. By using an ultrashort pulse which is sent through the
transparent eye structure, no thermal or athermal damage is
produced on the retina or other uninvolved regions. In the working
plane (for example, the lens, the vitreous body or in the cornea),
there exists an energy density of such a kind that indeed nothing
happens in the fully transparent medium of the eye but that
disruptions are induced at heterogeneous spots of clouding by local
absorption, the disruptions dissolving these impurities. These
disruptions result in the evaporation of these impurities.
The gas blisters (cavities) possibly forming in the process are
filled up in a few hours and disappear in this manner. The
dissolved impurities are reduced by resorption and/or dispersion,
or disappear completely.
Pulses which lie in the ps range are preferably used as ultrashort
pulses; particular preference being given to pulses which lie in
the fs range. It is preferred to use pulses of from 10 ps to 10 fs,
particularly preferably of 300 fs.
The special advantage of the method according to the present
invention lies in that the opacities and/or hardenings of the eye
can be removed or reduced without having to open the eye. In this
manner, the risks involved in surgery are avoided. Using the method
according to the present invention, moreover, a treatment which is
more gentle and carried out in small steps can be accomplished by
appropriate selection of the energy of the ultrashort pulse.
It is preferred for the ultrashort pulses to be further amplified,
particularly preferably via the Chirped Pulse Amplification Method
(CPA method).
In a preferred method according to the present invention, the
opacities and/or hardenings are dissolved with the assistance of a
pulse train having a duration of less than 5 s, preferably less
than 3 s, particularly preferably less than 0.1 s of the ultrashort
pulses. It is very particularly preferred to provide pulse lengths
in the range of from 10 ps to 10 fs, and especially preferably of
approximately 300 fs. The energy input in the region to be treated
can be predetermined via the selection of a pulse train by
determining the duration. By selecting extremely short pulse
trains, it is possible, moreover, to prevent efficiency losses
which could occur, for example, because of a movement of the eye
during the treatment. The pulses particularly preferably have a
duration of less than 10 ps. It is also conceivable to use the
pulse train in continuous operation until the desired effect has
been attained. Very particularly preferably, it is also possible to
use single pulses and very short pulse trains to achieve a
particularly gentle treatment by iteratively monitoring the success
of treatment.
In a further preferred method of the present invention, pulse
trains with a repetition frequency, in particular, with a
repetition frequency in the kHz range are emitted. In this
connection, the pulse trains themselves are superposed with a
repetition frequency once again. In this manner, the energy input
into the region to be treated can be varied over time once more in
spite of the selection of a longer pulse train or even of a
continuous operation. Because of this, an even more gentle
treatment is possible, avoiding any thermal or athermal damage to
the eye in regions which are not intended to be treated.
In a further preferred method of the present invention, one chooses
a laser radiation of a wavelength distribution which has a higher
absorption and/or a lower reflection for the opacities and/or
hardenings than for the remaining parts of the eye. In this manner,
it is possible to adjust the energy density in such a manner that
the density required for triggering an optical breakdown is only
reached at locations of local absorption. This selective adjustment
is attained through the increased absorption of the opacities
and/or hardenings at the selected wavelengths. It is particularly
preferred to chose a laser for whose wavelength the eye is highly
transmissive. The wavelength is preferably 350 to 1300 nm. It is
particularly preferred to chose a laser to whose radiation the
sensitive regions such as the retina or the macula are somewhat
less sensitive. This can be accomplished via a lower absorptivity
of these regions in the eye for the selected radiation. This can
also be achieved by a higher reflectivity of the regions of the eye
which are not to be treated. Thus, the radiation cannot cause any
damage in the regions of the eye which are not to be treated just
because of the absorptive and reflective behavior, independently of
the energy density which can be generated by focusing.
In a further preferred method of the present invention, ultrashort
pulses are aligned in such a manner that energy densities which
dissolve the opacities and/or hardenings occur within the opacities
and/or hardenings while, at the same time, no damage is caused to
the tissue in the sensitive region of the eye. Apart from the
selection of the wavelength, this can be accomplished by a
focussing of the beam and a corresponding beam guidance of the
pulses. Thus, by shaping the beam geometry of the pulse, it is
possible to couple in energy densities in the region of the tissue
to be treated which give rise to a disruption (and, consequently,
to the dissolution) of the pathological (less transparent) tissue.
At the same time, the beam can be shaped in such a manner that, in
the area of sensitive regions such as the retina and, in
particular, the macula, energy densities occur which do not result
in the destruction of this tissue.
This can preferably be attained via the beam guidance in that, upon
passage of the beam through the target region to be treated, the
beam is widened in such a manner that the energy densities in the
sensitive region are so low that the region cannot be damaged. In a
further preferred method, the complete eye lens or a region thereof
having a preselected size is irradiated with a converging beam of
rays and an energy density in the region of the lens below that of
the optical breakdown. In the process, the focus lies in the
vitreous body. On the other hand, the energy is selected such that,
given transparency of the lens, an optical breakdown occurs at the
focus in the vitreous body. Since all the energy is consumed during
the optical breakdown at the focus, it is possible to provide a
high level of treatment safety with regard to the macula. Any
possible formation of blisters in the vitreous body will relax
after a short time.
In a further preferred method of the present invention, the
alignment of the ultrashort pulses takes place via a deflection
device and/or focusing optics and/or a contact glass. This makes it
possible not only to accurately align the ultrashort pulses and the
thereby described beam with the region to be treated but also to
preselect the energy density which is desired in the target region.
By drawing upon known devices, it is possible for the method
according to the present invention to be implemented in
cost-effective manner.
In another preferred method of the present invention, data on the
opacities and/or hardenings is acquired by measuring reflected
radiation of low energy prior to the actual treatment, this
acquired data being taken into account in the selection of the
alignments of the energy of the pulses to be used. To protect the
sensitive regions, in fact, it lies especially also within the
scope of the present invention to irradiate with considerably lower
intensities which are harmless to the eye prior to the actual
therapeutic radiation, and to draw conclusions on the alignment of
the laser and on the radiation dose required in the specific
radiation direction on the basis of the radiation which is
reflected, for example, at the opacities. Since the energy of the
radiation is substantially used up during the disruption of
opacities, optimum adaptation of the beam geometry to the opacities
to be treated is also advantageous for the gentle treatment of the
sensitive regions. The thus acquired data permits individual and
well-directed treatment of the identified regions. In particular,
this data can also be acquired between the individual treatment
steps to ascertain the extent of success the treatment has shown so
far. Thus, it is possible, for example, to sent a low-energy signal
after an ultrashort pulse or a pulse train to obtain data therefrom
on the changes caused by the ultrashort pulse or pulse train in the
region to be treated.
In a further method according to the present invention for treating
the presbyopia of an eye, blisters are produced in the lens of the
eye, and these blisters are filled with liquid without having to
open the eye. This formation of blisters inside of the lens gives
rise to a loosening of the lens material. The blisters formed in
this manner are automatically filled with liquid again. Because of
these blisters filled with liquid, a lens is produced which has a
higher flexibility than the original lens. However, the
accommodation of the lens is thereby increased.
It is particularly preferred for the blisters to be produced as
blister fields in the marginal area of the lens. This placing of
blisters in the marginal area or in the marginal zone of the lens
results in a softening of the lens upon filling with liquid. This
brings about a higher flexibility and, thus, a higher accommodation
of the lens. Via a symmetrical arrangement of the blister fields,
it is possible for the accommodative capacity of the lens to be
preserved symmetrically. In the case that the lens is hardened only
partially, then the flexibility of the lens can be increased in a
particular region by selective formation of blisters. In this
manner, it is possible to improve the overall symmetry of the lens
during accommodation.
The object of the present invention is achieved, moreover, by a
device for treating opacities and/or hardenings of an unopened eye,
including a laser having a frequency distribution in the range of
from 350 nm to 1300 nm as well as a device for generating
ultrashort pulses, provision being made for a device for aligning
the ultrashort pulses, including a deflection device and/or
focusing optics and/or a contact glass, provision being made for a
control device via which the device for aligning the ultrashort
pulses is controlled as a function of data on the opacities and/or
hardenings. Using this device, it is possible to accomplish the
above advantages of the method according to the present invention.
The optical means for coupling in the radiation are preferably
constituted by tunable focusing optics, deflection mirrors of a
micromanipulator, contact glasses, special mirror contact glasses
and surgical microscopes or slitlamps. Using these elements, it is
possible for the beam to be set up and aligned inside of the eye in
such a manner that the energy input can be predetermined very
precisely in the regions to be treated without the possibility that
an energy density might occur outside of these regions to be
treated which is detrimental for the tissue existing there. In a
further preferred exemplary embodiment of the present invention,
provision is made for a control device via which the device for
aligning the ultrashort pulses can be controlled, particularly
preferably as a function of data on the opacities and/or
hardenings. Using this control device, the data which has been
ascertained on the regions to be treated can be prepared in such a
manner that the pulse duration, sequence, and the energy density to
be introduced can be determined and that the device for aligning
the ultrashort pulses can be set up and aligned via the control
device on the basis of the determined parameters by adjusting the
individual elements of the optical system via the control device in
such a manner that the desired region can be treated with the
predetermined energy input. The laser is selected such that it
canlemit pulses in the ps range, preferably in the fs range.
In a further refinement, the laser as coherent light source
includes a device for generating at least one pulse train. This
pulse train has preferably a duration of less than 5 s, especially
preferably less than 2 s and, particularly preferably, of less than
0.1 s. It is particularly preferred to provide pulse lengths in the
range of from 10 ps to 10 fs and, very particularly preferably,
pulse lengths of approximately 300 fs. The device according to the
present invention is preferably also able to provide pulse trains
in continuous operation or to emit single pulses. Using the device
for generating pulse trains with a repetition frequency,
particularly preferably in the kHz range, of the laser as coherent
light source, it is possible to produce the superposition of the
individual pulse trains with the repetition frequency described in
the method according to the present invention, increasing the
gentle introduction of the energy into the region to be
treated.
The coherent light source particularly preferably features a device
for generating a laser radiation having a frequency distribution
which has a higher absorption and/or a lower reflection for the
opacities and/or hardenings than for the remaining parts of the
eye. For that purpose, it is particularly preferred to use a
tunable laser which is able to radiate in the range of from 350 nm
to 1300 nm. It is particularly preferred to provide a laser which
is able to radiate in the range of 780 nm, such as a Ti-sapphire
laser or, also preferably, in the range of 1060 nm, such as an
Nd:glass laser. Using such a laser, it is possible to attain the
advantages of the method according to the present invention.
The object is achieved according to the present invention by using
a device or method according to the present invention for the
treatment of haze formation in the cornea subsequent in excimer
laser treatments, in the case of cloudings of the lens nucleus, in
the case of incipient cataract and/or for impurities of the
vitreous body in the visual field.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, exemplary embodiments of the present invention
and advantageous refinements will be explained in greater detail on
the basis of drawings. In this context,
FIG. 1 shows an exemplary embodiment of the device according to the
present invention for treating an opacity in the visual field of
the vitreous body.
FIG. 2 depicts an exemplary embodiment of the present invention for
treating presbyopia;
FIG. 3 depicts a further exemplary embodiment of the present
invention for treating the eye lens;
FIG. 4 shows a further exemplary embodiment of the present
invention for treating a particular region of the eye lens; and
FIG. 5 is a diagram of a pulse train with a representation of the
time axis and amplitude.
DETAILED DESCRIPTION
FIG. 1 shows a first exemplary embodiment of the present invention
for treating an opacity in the vitreous body in the visual field
directly behind the lens. Focusing optics 12 are connected
downstream of a laser 10, here a mode-locked laser. A deflection
mirror with micromanipulator 14 is arranged downstream of the
focusing optics. A contact glass 15 is placed on the eye 1 to be
treated. A clouded region 5 is situated downstream of the eye lens.
A surgical microscope with slitlamp 19 is used for monitoring.
The mode-locked laser system is used to generate ultrashort laser
pulses, preferably of 10 ps to 10 fs, which are further amplified
using the Chirped Pulse Amplification Method to make available
pulse energies above 1 ml in the kHz range. At the wavelength of
780 nm (Ti-sapphire) or 1060 nm (Nd:glass), the transparent regions
of the cornea, lens or vitreous body to be treated have a low
absorption which are not damaged when irradiated with sufficiently
low energy densities of the ultrashort pulse. A focusing device 12
which is used for aligning and focusing the beam is arranged
downstream of laser 10. The beam is focused via deflection mirror
with micromanipulator 14 through contact glass 15 onto clouded
region 5.
During operation, the laser emits pulse trains 25 of ultrashort
pulses 20. These are only absorbed by the pathological clouded
regions whereby a selective treatment is rendered possible. In the
process, the ultrashort pulses result in a locally limited,
disruptive size reduction process of the clouded tissue without
detrimental thermal side effects. Upon the filling of the induced
blisters, the local, selective and athermal size reduction process
restores transparency in this region. Possibly developing
cavitations in the vitreous body are refilled with liquid by the
body within a short time. In this manner, region 5 becomes
transparent again after the treatment.
Given an appropriate selection of energy, it is also possible to
treat clouded regions in the eye lens using this arrangement. In
this connection, the energy is selected such that the transparent
parts of the eye lens do not permit absorption of the selected
wavelength. The clouded regions in the eye lens, however, absorb
the radiation and thus, the ultrashort pulses give rise to a
locally limited, disruptive size reduction process of the clouded
tissue also in the eye lens without detrimental thermal side
effects. The energy which were not absorbed by the clouded regions
are used up by disportion at the focus in the vitreous body and,
consequently, cannot damage the retina. The cavitations developing
the vitreous body are refilled the liquid of the body within a
short time and, consequently, are transparent again.
FIG. 2 depicts an exemplary embodiment of the present invention for
treating presbyopia. The device corresponds essentially to that in
FIG. 1. However, the beam deflection of the pulse train takes place
via deflection mirror with micromanipulator 14 in such a manner
that the focus comes to rest in the marginal area of the lens.
According to the present invention, the blisters can thus be
produced preferably in the marginal area of the lens which, upon
filling with preferably endogenous fluid, have a higher flexibility
and therefore accommodative capacity. In this manner, it is
possible to place whole fields of blisters, resulting in a regional
softening of the lens and, consequently, in a corresponding
increase in flexibility.
FIG. 3 depicts another exemplary embodiment of the present
invention for treating the eye lens. This exemplary embodiment also
corresponds to that shown in FIG. 1 in its essential design. Via
optical system 12 used here, however, the beam is widened in such a
manner that it can be adjusted in the area of eye lens 2 so as to
produce an energy input here which results in a destruction of
clouded regions 5 in lens 2 while, in its further course, the beam
is widened in such a manner that the energy in the area of macula 7
is so low that no damage can be caused to the tissue here.
Via special divergent beam guidance and appropriate irradiation as
well as possible automated scanning methods, the radiation is
guided during the treatment in such a manner that neither the
retina nor any locations other than the pathological ones can be
damaged.
FIG. 4 is a another exemplary embodiment of the present invention
for treating a particular region of eye lens 2. In this context, a
mirror 16 is provided in contact glass 15, the mirror making it
possible for the pulse train to be aligned with a particular region
of the eye lens. The beam impinges on deflection mirror with
micromanipulator 14 which sets up the beam through contact glass 15
onto mirror 16 in contact glass 15, the mirror 16 aligning the beam
with the area of eye lens 2 in which clouded region 5 exist.
FIG. 5 shows a diagram of a pulse train 25 with a representation of
the time axis and amplitude. The individual ultrashort pulses 20
have a width of several femto-seconds. Pulse train 25 is formed of
three pulse bursts 22 of different lengths 22.1, 22.2 and 22.3, and
superposed with a frequency sequence having the period T. In this
manner, the energy input via the ultrashort pulses can be further
varied. While time t is represented on the x-axis, amplitude A is
indicated on the y-axis. In lieu of a frequency sequence in the kHz
range, a linear or a quasi-linear rising envelope or falling
envelope can also be thought of. First pulse burst 22.1 is
constituted by one single pulse 20. Pulse train 22.2 is constituted
by several single pulses which, in turn, are spaced from one
another by time T. T usually lies in the ms range while the width
of single pulses 20 lies in the fs range. Pulse train 25 is formed
of the pulse bursts together with pulse burst 22.3.
According to the present invention, a method at and a device for
treating opacities and/or hardenings of an unopened eye was
introduced. A special advantage of the design approach according to
the present invention is that it enables treatments to be carried
out inside the eye without having to introduce a surgical
instrument into the eye.
List of Reference Symbols
1. eye 2. lens 3. vitreous body 4. cornea 5. opacities 7. macula
10. laser 12. optical system (focusing optics) 14. deflection
mirror with micromanipulator 15. contact glass 16. mirror in the
contact glass 19. surgical microscope with slitlamp 20. ultrashort
pulse 22. pulse burst 25. pulse train
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