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Home > Archive > Lasik Eyes Surgery > May 2005 > Better cornea transplant technique on the horizon for lasik disasters and other patien
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Better cornea transplant technique on the horizon for lasik disasters and other patien
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| Sandy - LASIKdisaster.com - LASIKmemorial.com 2005-05-07, 8:57 am |
| UCI eye doctors invent laser-assisted cornea-transplant surgery
04 May 2005
A UC Irvine ophthalmologist and his team have invented a new
laser-surgery technique to perform cornea-transplant surgery that can
replace the use of traditional handheld surgical blades and potentially
improve recovery time for patients.
The technique was developed by Dr. Roger F. Steinert, director of
cornea, refractive and cataract surgery in UCI Health Sciences. Cornea
transplants are performed on the "front window" of the eye, using
living tissue from donors to replace corneas in which swelling, scars,
distortions and degenerations are causing blindness. The work will be
presented today at the Association for Research in Vision and
Ophthalmology meeting, the largest eye research meeting in the world,
in Fort Lauderdale, Fla.
The work will lead to human application of the high-tech procedure.
Clinical trials are expected to begin by this summer at UCI.
While most transplants are successful in providing the patient with a
clear cornea, the majority of cornea transplants take more than six
months to provide good vision, and even then strong glasses or contact
lenses are needed. In addition, stitches usually need to stay in place
for years, because the cornea is slow to heal and, as a result, the
transplant remains a weak spot, vulnerable to injury for the rest of
the patient's life. After the laser-based transplant, suture removal
may be as soon as three months, and the strength of the repaired area
may be nearly 10 times that of conventional transplants.
"By using the laser, a highly precise incision is created, resulting in
a perfect match of the donor and the patient," said Steinert, a
professor of ophthalmology in the School of Medicine. "In addition to
precision that exceeds anything that can be duplicated by even a highly
skilled surgeon, the laser can create complex shapes that are
impossible to achieve with conventional surgery."
The study compared the results of conventional transplant surgical
techniques to the results of the laser surgery. Utilizing 14 donated
human corneas that were not medically suitable for transplantation,
Steinert and his team performed simulated transplant surgery and then
tested for the mechanical strength of the incisions and for induced
distortion.
They found that the initial strength of the laser incision, even before
any healing, measured almost seven times higher than that of the
incision from the usual transplant technique performed by hand.
The laser used to cut the cornea is known as a femtosecond-pulsed
laser, manufactured by Irvine-based IntraLase Corp. The laser fires
15,000 pulses per second, each pulse lasting only 400 quadrillionths of
a second. (To understand how brief each laser pulse lasts, in one
second a pulse of light would travel around the equator of the Earth
seven times, but in one femtosecond a pulse of laser travels only the
width of three human hairs.)
The location of the pulses in the cornea to create the incision is
controlled by sophisticated optics and a computer, so that each pulse
interconnects with the next, similar to the perforations in paper
sheets that allow the paper to be torn cleanly.
As many as 40,000 cornea transplants are performed each year in the
United States. The most common reasons for this procedure are swelling,
clouding after damage from other eye diseases -- a distortion known as
keratoconus -- and scarring after injuries or infections.
Co-workers on this project included Dr. Ronald Kurtz, associate
professor of ophthalmology at UCI and co-inventor of the laser; Dr.
Melvin Sarayba, project director at IntraLase, and Dr. Theresa Ignacio,
a UCI research fellow. Steinert also is a professor of biomedical
engineering and vice chair of clinical ophthalmology at UCI.
About the university of California, Irvine: Celebrating 40 years of
innovation, the university of California, Irvine is a top-ranked public
university dedicated to research, scholarship and community service.
Founded in 1965, UCI is among the fastest-growing university of
California campuses, with more than 24,000 undergraduate and graduate
students and about 1,400 faculty members. The second-largest employer
in dynamic Orange County, UCI contributes an annual economic impact of
$3 billion. For more UCI news, visit http://www.today.uci.edu.
Contact: Tom Vasich
(949) 824-6455
tmvasich@uci.edu
UCI maintains an online directory of faculty available as experts to
the media. To access, visit http://www.today.uci.edu/experts.
Contact: Tom Vasich
tmvasich@uci.edu
949-824-6455
University of California - Irvine
http://www.uci.edu
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| Glenn - USAEyes.org 2005-05-07, 11:55 am |
| Dr. Steinert is a transplant himself, of sorts. He recently relocated
to UC Irvine from Boston, where he had practiced for years.
The femtosecond laser was developed for creation of LASIK flaps, but
is finding uses in many other areas. This press release relates to a
full corneal transplant, also known as Penetrating Keratoplasty (PKP).
PKPs are no fun, have a long vision recovery period, and are not
terribly predictable.
PKP with the Intralase creating both the donor cornea and removal of
the recipient's corneal plug induces less astigmatism, provides a more
even surface (donor to recipient) and seems to have a slightly faster
vision recovery.
A new technique where the femtosecond laser REALLY shines is Deep
Lamellar Endothelial Keratoplasty (DLEK).
When the endothelial cells become compromised, a transplant can often
resolve the problem. Unfortunately, transplanting just the
endothelial layer and its basement membrane (Decement's layer) on the
underside of the cornea is not exactly easy. Development of DLEK
using mechanical scalpels and customized cutting tools works, but
tends to create a very uneven transplant with poor adhesion.
The femtosecond makes this surgery almost easy. From the front side
of the cornea, the laser creates a lamellar incision in the
recipient's cornea just anterior to Decement's. When this circular
incision is complete, the laser then cuts the side by making incision
from the level of the lamellar incision back through the bottom of the
cornea. This creates a disk of just Decement's and Endothelium in a
very precise form - within about 10 microns of desired size.
The laser then creates an identical disk from donor tissue using the
same process. The recipient's disk is rolled up and removed through a
relatively small (by PKP standards, anyway) 5.0mm incision at the edge
of the cornea, and the donor disk is rolled up and unfolded in the
"hole" created by the removal of the recipient's disk.
The cornea's natural "suction" holds the disk in place without sutures
or biological glues. DLEK is an alternative to PKP, which requires
the full thickness of the cornea to be replaced.
The leading causes of corneal transplants are endothelial cell
dystrophy (Fuch's Dystrophy) and keratoconus. Corneal transplant
required exclusively because of refractive surgery is a very, very
small portion, but are made safer and more predictable with the
femtosecond laser.
Glenn Hagele
Executive Director
Council for Refractive Surgery Quality Assurance
Email to glenn dot hagele at usaeyes dot org
http://www.USAEyes.org
http://www.ComplicatedEyes.org
I am not a doctor.
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| lwoodlock@msn.com 2005-05-18, 11:45 am |
| I have to disagree with Glenn's statement that corneal transplant is
safer and more predictable with the femtosecond laser. I have had a
deep lamellar graft with the Intralase and it was unsuccessful. I
could only "see" color and light and could not distinguish the faces on
my children. I had sutures in place for approximately 3 to 4 months
and the vision was uncorrectable with glasses or contacts. The doctor
told me that they were easy to perform but were very unpredictable and
said that he would not do them anymore. He did a deep lamellar graft
by hand and that one did not work either and he finally did a PKP. He
has since retired. I have met other Intralase patients with similar
outcomes and they went on to have PKP also.
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| Glenn - USAEyes.org 2005-05-18, 11:45 am |
| There are several points on which you touch and I'd like to hear your
opinions on a couple of things
What was the underlying reason for the need for corneal surgery?
You had a Deep Anterior Lamellar Keratoplasty (DALK) using the
Intralase that did not provide good results, and you had a DALK with a
mechanical microkeratome that failed. How do you attribute the
failure of DALK on the type of microkeratome used when a graft failed
with both types of microkeratomes?
A DALK is not the same as the Deep Lamellar Epithelial Keratoplasty
(DLEK) that I described in my previous post. DLEK does not require
stitches on the donor tissue (but does for the 3-5mm entrance incision
at the edge of cornea.
And please keep in mind that the statement that corneal surgery is
safer and more predictable is not just mine. It is the opinion Dr.
Steinert, who was mentioned in the article, and many other surgeons.
Of course, safer and more predictable does not guarantee the desired
outcome...unfortunately. At best, it increases the probability of
success and decreases the probability of surprises.
Glenn Hagele
Executive Director
USAEyes.org
"Consider and Choose With Confidence"
Email to glenn dot hagele at usaeyes dot org
http://www.USAEyes.org
http://www.ComplicatedEyes.org
I am not a doctor.
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| Sandy - LASIKdisaster.com - LASIKmemorial.com 2005-05-18, 11:45 am |
| I know of another patient who had an Intralase cut for her graft, and
it was also unsuccessful. She was kicked in the eye by her baby
post-lasik, and the flap couldn't be smoothed out. She cannot see
much with the graft eye.
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| lwoodlock@msn.com 2005-05-18, 11:45 am |
| I have had the transplants because of failed LASIK surgery. Dr.
Nordan (my surgeon) said the Intralase created interface problems that
he could not explain. He said some patients did well and others did
not and said that it was unpredictable. The hand LKP (from what I am
told) is more difficult to perform than a PK and the odds of a good
result are not as good as a PK but if it works the healing time is much
shorter. Dr. Nordan said that I needed to replace my damaged cornea
and it was worth a chance to try the LKP because of the shorter healing
time and if it didn't work I was going to have to have a PK anyways.
I am just a LASIK patient telling what happened to me. The one thing
that stands out in my mind was when I was waiting for my transplants is
that the other patients were there for the same reason as I was ...
failed LASIK.
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| Ragnar 2005-05-18, 11:46 am |
| Hopefully someone can add more to this post.
What I find interesting is that about 2 years ago, Dr. Nordan was
marketing his training of optometrists to do all laser lasikwith the
intralase. At the time, one of the major selling points of the
intralase system didn't involve a blade - so technically optometrists
could perform lasik. Dr. Nordan was ACTIVELY recruiting optometrists
for this explicit purpose. Interestingly, he wasn't suggesting that
ophthalmologists take the training. To the best of my understanding,
he retired from practicing a few months after that fiasco, then
published a sour grapes article about how other surgeons did lasik and
promised an ongoing series of articles about that. He didn't write
any more articles about it.
Out of all those trainined, a total of 5 optometrists are now doing
the intralase lasik procedure.
I don't doubt what you say... and it explains something about the
"esteemed" Dr. Nordan.
On 12 May 2005 23:14:00 -0700, lwoodlock@msn.com wrote:
>I have had the transplants because of failed LASIK surgery. Dr.
>Nordan (my surgeon) said the Intralase created interface problems that
>he could not explain. He said some patients did well and others did
>not and said that it was unpredictable. The hand LKP (from what I am
>told) is more difficult to perform than a PK and the odds of a good
>result are not as good as a PK but if it works the healing time is much
>shorter. Dr. Nordan said that I needed to replace my damaged cornea
>and it was worth a chance to try the LKP because of the shorter healing
>time and if it didn't work I was going to have to have a PK anyways.
>
>I am just a LASIK patient telling what happened to me. The one thing
>that stands out in my mind was when I was waiting for my transplants is
>that the other patients were there for the same reason as I was ...
>failed LASIK.
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| Glenn - USAEyes.org 2005-05-18, 11:46 am |
| What you have related seems to be exactly the current thinking
regarding corneal transplant. A lamellar graft is the first line of
defense because if it works, it is slightly less invasive, provides
greater stability, and has a shorter recovery period. If the lamellar
graft fails, then the patient is looking at a full-depth transplant,
which is what the patient was looking at before attempting the graft.
If Dr. Nordan could not understand what was odd about the Intralase
incision, then I certainly could not come up with a better answer.
While Dr. Nordan was practicing he had a solid reputation as a doctor
to go to with difficult problems. It does not surprise me at all that
other patients with refractive surgery induced problems were in his
waiting room. We recommend him as well as many others.
It sounds like your vision has been restored by the transplant. What
is your vision like today?
Glenn Hagele
Executive Director
USAEyes.org
"Consider and Choose With Confidence"
Email to glenn dot hagele at usaeyes dot org
http://www.USAEyes.org
http://www.ComplicatedEyes.org
I am not a doctor.
| |
| lwoodlock@msn.com 2005-05-18, 11:46 am |
|
Glenn - USAEyes. org wrote:
> What you have related seems to be exactly the current thinking
> regarding corneal transplant. A lamellar graft is the first line of
> defense because if it works, it is slightly less invasive, provides
> greater stability, and has a shorter recovery period. If the
lamellar
> graft fails, then the patient is looking at a full-depth transplant,
> which is what the patient was looking at before attempting the graft.
>
> If Dr. Nordan could not understand what was odd about the Intralase
> incision, then I certainly could not come up with a better answer.
>
> While Dr. Nordan was practicing he had a solid reputation as a doctor
> to go to with difficult problems. It does not surprise me at all
that
> other patients with refractive surgery induced problems were in his
> waiting room. We recommend him as well as many others.
>
> It sounds like your vision has been restored by the transplant. What
> is your vision like today?
>
> Glenn Hagele
> Executive Director
> USAEyes.org
>
> "Consider and Choose With Confidence"
>
> Email to glenn dot hagele at usaeyes dot org
>
> http://www.USAEyes.org
> http://www.ComplicatedEyes.org
>
> I am not a doctor.
Well ... where do I start? I will give the condensed version.
Since the PK, I have had 3 AK's with compression sutures and a wedge
resection to try and correct 16 diopters of astigmatism. The cornea is
clear but very difficult to try and find a lense that fits AND won't
harm the eye. When I have a lense in the vision is a single image
20/40 which I am happy about ... problem is that I can't wear the lense
more than a couple of hours without causing erosions or NV. My other
eye is correctable to 20/60 - 20/70 multiple image with rgp lense.
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