Lasik Eyes Surgery - Look how far they have come in 12 years.

Author

Look how far they have come in 12 years.

Glenn - USAEyes.org

2004-11-06, 11:09 am

What really caught my attention in this study was not that PRK remains
stable. That was expected. It was the outlandish complication rates
from the technology and techniques used a dozen years ago.

A 4.0mm ablation zone with no transition zone would (should) never
happen today. I'm surprised that the nighttime halo problem isn't
100% instead of the reported 12%.

The PRK induced dry eye is significantly more than we currently see.
Undoubtedly that would be because of no transition zone, making the
cornea a very uneven place for tear film.

All of these were moderate myopes, but 4% developed haze. Even though
it eventually dissipated some, that is a rate of PRK induced haze that
is today not even found in high myopes.

Although by medical standards these outcomes are considered stable and
predictive, this study shows how being the first to have a totally new
procedure may not be the best.

~~~~~~~~~~~~~~~~

Long-term Study of PRK: 12-year Follow-up Results

Investigators at London’s St. Thomas’ Hospital conducted a long-term
prospective follow-up study to evaluate the refractive stability of
excimer laser myopic photorefractive keratectomy (PRK).

Of the original cohort of 120 patients who participated in the first
United Kingdom excimer laser clinical trial, 68 (56.6 percent)
underwent detailed clinical assessment at 12 years after myopic PRK.
The PRK had been performed using the Summit Technology UV 200 excimer
laser with a 4-mm ablation zone. Patients were allocated to one of six
treatment groups based on their preoperative refraction. Each group
received one of the following spherical corrections: -2, -3, -4, -5,
-6 or -7 diopters (D). Patients in each group received an identical
treatment; therefore, emmetropia was not the primary aim. In addition
to refractive stability, main outcome measures were refractive
predictability, best spectacle-corrected visual acuity (BSCVA) and
corneal haze.

The postoperative refraction remained stable at 12 years, with no
significant change in mean spherical equivalent refraction between
one, six and 12 years. Seventy-five percent of patients who underwent
a -2.00D correction and 65 percent of patients who received a -3.00D
correction were within 1.00D of intended correction at 12 years.
Fifty-seven percent of the -4.00D group and 50 percent of the -5.00D
group were within 1.00D, and this was further reduced to 25 percent
and 22 percent in the -6.00D and -7.00D groups, respectively. Four
percent had residual corneal haze and 12 percent had persistent
nighttime halos at 12 years. Dry eyes were encountered in three
percent of patients; none of the eyes developed corneal ectasia in the
long term.

The authors of the study concluded that in myopic PRK, refractive
stability achieved at one year was maintained up to 12 years with no
evidence of hyperopic shift, diurnal fluctuation or late regression in
the long term. Corneal haze decreased with time, with complete
recovery of BSCVA. Night halos remained a significant problem in a
subset of patients because of the small ablation zone size.

SOURCE: Rajan MS, Jaycock P, O'Brart D, et al. A long-term study of
photorefractive keratectomy; 12-year follow-up. Ophthalmol
2004;111(10):1813-24.

Wizkid

2004-11-07, 7:11 pm

I agree with you on this...I would expect PRK to be stable as there is
no cutting of a flap that compromises both the strength and the
homogenity of the cornea. Surface ablation means just that. It is not
corneal destruction which is an attribute of LASIK. WK

Glenn - USAEyes.org

2004-11-07, 7:11 pm

>I agree with you on this...I would expect PRK to be stable as there is
>no cutting of a flap that compromises both the strength and the
>homogenity of the cornea. Surface ablation means just that. It is not
>corneal destruction which is an attribute of LASIK. WK

Certainly the amount of untouched cornea with PRK will be much greater
than with LASIK, but both procedures require the "destruction" of
corneal tissue to achieve a change in refractive error.

Ready to answer those questions yet, WizKid?

1) What to you believe to be the safe minimum untouched cornea after
LASIK required in a healthy eye?

2) How long can a 20-year-old patient who has an endothelial cell
count of 1800/mm2 safely have an Artisan/Verisyse phakic intraocular
lens implanted, considering that there are no other complications?

3) What information do you believe a patient needs to review before
successfully completing an informed consent process for LASIK and can
make an informed decision.

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.

Ragnar Suomi

2004-11-08, 7:12 pm

That sounds reasonable, but his wrong.
The outer layers of the cornea regenerate a bit which is why in PRK
the procedure must be over-corrected to take into account the
significant regression.. The deeper layers ablated by LASIK do not
regenerate - so regression is very minor.

On 7 Nov 2004 15:00:46 -0800, gospa68@aol.com (Wizkid) wrote:

>I agree with you on this...I would expect PRK to be stable as there is
>no cutting of a flap that compromises both the strength and the
>homogenity of the cornea. Surface ablation means just that. It is not
>corneal destruction which is an attribute of LASIK. WK

Glenn - USAEyes.org

2004-11-08, 7:13 pm

>The outer layers of the cornea regenerate a bit which is why in PRK
>the procedure must be over-corrected to take into account the
>significant regression.. The deeper layers ablated by LASIK do not
>regenerate - so regression is very minor.

Ragnar, that is not totally consistent with my understanding.

The outermost layer of corneal cells is the epithelial layer. These
are the fastest reproducing cells in the human body. In the process
of PRK, these cells are removed and would actually cause a slight
overcorrection by their removal. Within days the cells have covered
the treatment area and within weeks have built back up to their
pre-surgical level.

In some cases the epithelial layer will become thicker than it was
before surgery, and in very rare cases they will grow at a rate and
size as to make the epithelial layer significantly thicker than
preoperative levels.

This epithelial layer does change shape and remodel after refractive
surgery. Essentially, the cornea is trying to put itself back to the
shape it was in before surgery. For this reason, the epithelial layer
may become very thick in the center for those with myopic
(nearsighted) correction, or become thick in the mid-periphery for
those with hyperopic (farsighted) correction. The remodeling seems to
affect the hyperopic patients more than myopic, and this remodeling is
consistent regardless of the technique, be it LASIK, PRK, LASEK, or
Epi-LASIK.

The corneal layers under the epithelium, the Bowman's layer and
stroma, are removed during the PRK laser ablation process and do not
regenerate. Only the stroma is removed during LASIK, and it does not
regenerate.

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.

Ragnar Suomi

2004-11-08, 7:13 pm

Well, maybe you ought to do a little more research. Try talking to
some of the surgeons you certify about it. Just what you mention
about the epithelium alone is reason enough to have LASIK instead of
PRK. The outer layers of the cornea also regenerate a bit, the inner
ones do not. The Bowman's layer - which many claim has such functions
as filtering UV light, providing a barrier against infection, and
strengthening the cornea, is removed in PRK. That is not good. But
miraculously, there is some talk that a Bowman's-like layer
regenerates a bit after PRK... hmm.. those outer layers seem to
regenerate...

I know that 1 or 2 of your certified surgeons are in love with PRK.
You pay far too much attention to them. I guarantee you that almost
none of your other surgeons agree with those two.

On Mon, 08 Nov 2004 20:13:43 GMT, Glenn - USAEyes.org
<glenn.hageleSTOPSPAM@USAEyes.org> wrote:

>
>Ragnar, that is not totally consistent with my understanding.
>
>The outermost layer of corneal cells is the epithelial layer. These
>are the fastest reproducing cells in the human body. In the process
>of PRK, these cells are removed and would actually cause a slight
>overcorrection by their removal. Within days the cells have covered
>the treatment area and within weeks have built back up to their
>pre-surgical level.
>
>In some cases the epithelial layer will become thicker than it was
>before surgery, and in very rare cases they will grow at a rate and
>size as to make the epithelial layer significantly thicker than
>preoperative levels.
>
>This epithelial layer does change shape and remodel after refractive
>surgery. Essentially, the cornea is trying to put itself back to the
>shape it was in before surgery. For this reason, the epithelial layer
>may become very thick in the center for those with myopic
>(nearsighted) correction, or become thick in the mid-periphery for
>those with hyperopic (farsighted) correction. The remodeling seems to
>affect the hyperopic patients more than myopic, and this remodeling is
>consistent regardless of the technique, be it LASIK, PRK, LASEK, or
>Epi-LASIK.
>
>The corneal layers under the epithelium, the Bowman's layer and
>stroma, are removed during the PRK laser ablation process and do not
>regenerate. Only the stroma is removed during LASIK, and it does not
>regenerate.
>
>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.

Glenn - USAEyes.org

2004-11-08, 7:13 pm

There is no doubt that in some instances LASIK has distinct advantages
over PRK, just like P-IOLs are more appropriate in some cases and RLE
is better in others. That does not make any particular technique
worthless. Each have their place.

There have been many studies about ultraviolet (UV) light passing
through the cornea and none have shown that UV light passing through
Bowman's is changed by an amount that is clinically significant. For
the most part, UV light passes through the cornea without restriction,
with or without Bowman's. That is why everyone should always use 100%
UV protection sun glasses.

The idea that Bowman's may protect against infection is an interesting
concept. Bowman's is a more dense layer of cells, and that may
actually prevent larger molecules from deeper penetration, however the
molecules normally involved with infections are rather small.

The cornea is an amazing part of the human anatomy, and will always
try to "fix" itself. It would not be at all surprising if long-term
PRK patients would have a higher density layer of cells just below the
epithelium. Pigs eyes do not have Bowman's, but they do have a higher
density stromal layer near the anterior surface.

There is a higher probability of infection with PRK than LASIK, but
infection with either technique is very rare and may not be enough of
a difference to weigh one procedure over another when all other
factors considered.

Our CRSQA Certified Refractive Surgeons are a somewhat rarified group.
I try to look at the refractive surgery community as a whole. At a
recent medical meeting an informal survey was taken in the audience
filled with refractive surgeons.

When ask how many consider PRK (or similar surface ablation techniques
such as LASEK or Epi-LASIK) as their primary choice, about 5% raised
their hands. When asked how many will perform PRK when factors
indicated (like think cornea), about 95% raised their hands. So it
would appear that about 5% of refractive surgeons will never do a
surface ablation, and about 5% will do surface ablation as often as
possible.

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.

Wizkid

2004-11-08, 10:08 pm

PRK and LASIK destroy the cornea in very different ways. PRK does it
superficially while LASIK does it structurally. There is a big
difference much as painting a house is superficial while removing load
bearing walls is structural. The consequences of the latter are much
more severe.

In answer to your questions...
1) I tell patients that come to me for advice (I do not do refractive
surgery)that we just do not know what the long term effects of cutting
the flap are...at any depth. Therefore, I do not believe that there is
any safe minimum. Patients have a right to know this.
2) We do not know yet. Worst has data out 18 years now. Additionally,
I think that you may find the whole subject of endothelial cell counts
one that is still open for more research. Check with the group at
Emory on this. They, too, will tell you that there is much we do not
know...very much like the effects of the LASIK flap. Therefore, this
too should be disclosed to any interested patient.
3) The patient has a right to know the incidence (based on FDA studies
as surgeon derived data is mostly non-controlled and self-serving) of
every possible complication that can affect his/her vision both short
term and long term. The patient makes the decision in his/her best
interests not the doctor. Anything short of this is arrogance and
immoral.

I continue to be amazed at some here who believe that they know what
is in the patient's best interest. If there is no problem, then just
let them reach that conclusion. I believe that top-down planning ended
with the fall of the USSR. It proved to be a failure. It is no less
true here.
WK

>
>
>
>

Glenn - USAEyes.org

2004-11-08, 10:08 pm

>PRK and LASIK destroy the cornea in very different ways. PRK does it
>superficially while LASIK does it structurally. There is a big
>difference much as painting a house is superficial while removing load
>bearing walls is structural. The consequences of the latter are much
>more severe.

You are making an erroneous analogy. Providing that the cornea is
healthy and at least 250 micron of cornea remains untouched, LASIK is
closer to removing a freestanding room divider, than removing a load
bearing wall (in the narrow confines of ectasia concerns).

>In answer to your questions...

I have repeated my questions for clarity. Thanks for finally
responding.

1) What to you believe to be the safe minimum untouched cornea after
LASIK required in a healthy eye?

>1) I tell patients that come to me for advice (I do not do refractive
>surgery)that we just do not know what the long term effects of cutting
>the flap are...at any depth. Therefore, I do not believe that there is
>any safe minimum. Patients have a right to know this.

No safe minimums, you say. Nonsense. Total nonsense. You chose to
ignore the combined knowledge of 50 years worth of lamellar surgery
and millions of patients world wide.

Let's put your "no safe minimum" to a simply test of logic:

If a patient with a 520 micron thick cornea has a 90 micron flap and
36 microns of ablated tissue, that patient has 394 microns of
untouched cornea. Are you seriously trying to convince the world
that a patient with a natural cornea of 394 microns thickness is at
the same danger of ectasia as a patient who had LASIK and now has 394
microns of untouched cornea?

Your answer simply shows your inability to apply reason and logic to
this issue.

2) How long can a 20-year-old patient who has an endothelial cell
count of 1800/mm2 safely have an Artisan/Verisyse phakic intraocular
lens implanted, considering that there are no other complications?

>2) We do not know yet. Worst has data out 18 years now. Additionally,
>I think that you may find the whole subject of endothelial cell counts
>one that is still open for more research. Check with the group at
>Emory on this. They, too, will tell you that there is much we do not
>know...very much like the effects of the LASIK flap. Therefore, this
>too should be disclosed to any interested patient.

Your inability to find relevant research is astounding. You come to
the conclusion that there is no safe minimum of untouched cornea in
LASIK with absolutely no studies to back up your statement, but when
there are nearly 20 years of studies about P-IOLs you decide nobody
knows what is going on.

P-IOLs are absolutely temporary. The only question is when and why
they need to be removed.

Obviously, cataract formation would be an indication for removal with
cataract surgery and IOL. The onset of full presbyopia would be an
indication for removal with Refractive Lens Exchange. These, along
with obvious complications, are the simple issues regarding P-IOL
removal. The less obvious is the issue of endothelial cell loss.

All studies show a rate of loss just a bit less than 2% per year, but
higher in the initial three years. So you can simply take an
endothelial cell count, calculate projected loss, and figure out when
that P-IOL needs to come out.

If you have a patient with cell count of 1800/mm2, then figure 10%
loss for the first three years. This is giving you a good margin of
error and takes into account trauma induced loss during surgery and
the accelerated loss during the first three years. That leaves the
patient with a count of bout 1620/mm2 at year three.

Using a constant 2% loss per year, the fourth year the count would be
projected to be 1588/mm2, the fifth year about 1556/mm2, the sixth
about 1521/mm2, and one and on. The FDA Panel discussed that a count
of 1600/mm2 is the safe minimum, but I think the final labeling says
1200/mm2. If the number is 1200/mm2, this patient would need to have
the lens removed in the 24th year postop, give or take, and your
mileage may vary. If the safe count is 1600/mm2, then this patient
can only have the lens for three years.

The long-term reality of P-IOLs for a patient who is 20 years old is
significantly different than a patient who is 35 years old, even if
the starting cell count is exactly the same. Let us take two patients
with the same 1800/mm2 starting cell count and who both develop a
cataract at age 65.

In the best case scenario, the 20 year old will get through the years
of good accommodation with the P-IOL, then at around age 44 could opt
for Refractive Lens Exchange. If this 20 year old did not have the
P-IOL removed at around age 44 and continued with it in until age 65
when a cataract is diagnosed, the cornea would have long ago been lost
to endothelial cell loss and/or it would be much too dangerous to do
cataract surgery.

The 35 year old would have the benefit of accommodation for a few
years, then the P-IOL would just provide good distance vision until
the cataract forms around age 65. Unfortunately, the P-IOL's clock
would have ran out when this patient was 60 and, again, the
endothelial count would be too low to safely do cataract surgery.

P-IOLs are NOT ticking time bombs, but their safe application does
have a very clear time limit, based upon cell loss. If the patient
lives long enough, the P-IOL will need to be removed for one reason or
another. If the P-IOL is not removed in a timely manner, significant
damage and complications will arise.

3) What information do you believe a patient needs to review before
successfully completing an informed consent process for LASIK and can
make an informed decision.

>3) The patient has a right to know the incidence (based on FDA studies
>as surgeon derived data is mostly non-controlled and self-serving) of
>every possible complication that can affect his/her vision both short
>term and long term. The patient makes the decision in his/her best
>interests not the doctor. Anything short of this is arrogance and
>immoral.

We pretty much agree on this one. Knowing of every complication along
with its rate of occurrence is good information. That way someone
knows to be relatively worried about dry eyes and their consequences
(about 3% complication rate at six months postop) and less worried
about something like ectasia (3/50ths of one percent) that can for the
most part be avoided altogether.

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.

Ragnar Suomi

2004-11-09, 7:12 pm

I'm glad we agree so much! I don't think anything you said below
conflicts with my thinking.
In your last paragraph, you mention that 5% of surgeons will never do
surface ablation and 95% would do it as factors dictated. Those 5%
who refuse to do surface ablation are some oddballs. My surgeon does
PRK as indicated. I asked him how often he has found it preferable to
do PRK. He said he's done it 3 times out of several thousand.

On Mon, 08 Nov 2004 23:02:31 GMT, Glenn - USAEyes.org
<glenn.hageleSTOPSPAM@USAEyes.org> wrote:

>There is no doubt that in some instances LASIK has distinct advantages
>over PRK, just like P-IOLs are more appropriate in some cases and RLE
>is better in others. That does not make any particular technique
>worthless. Each have their place.
>
>There have been many studies about ultraviolet (UV) light passing
>through the cornea and none have shown that UV light passing through
>Bowman's is changed by an amount that is clinically significant. For
>the most part, UV light passes through the cornea without restriction,
>with or without Bowman's. That is why everyone should always use 100%
>UV protection sun glasses.
>
>The idea that Bowman's may protect against infection is an interesting
>concept. Bowman's is a more dense layer of cells, and that may
>actually prevent larger molecules from deeper penetration, however the
>molecules normally involved with infections are rather small.
>
>The cornea is an amazing part of the human anatomy, and will always
>try to "fix" itself. It would not be at all surprising if long-term
>PRK patients would have a higher density layer of cells just below the
>epithelium. Pigs eyes do not have Bowman's, but they do have a higher
>density stromal layer near the anterior surface.
>
>There is a higher probability of infection with PRK than LASIK, but
>infection with either technique is very rare and may not be enough of
>a difference to weigh one procedure over another when all other
>factors considered.
>
>Our CRSQA Certified Refractive Surgeons are a somewhat rarified group.
>I try to look at the refractive surgery community as a whole. At a
>recent medical meeting an informal survey was taken in the audience
>filled with refractive surgeons.
>
>When ask how many consider PRK (or similar surface ablation techniques
>such as LASEK or Epi-LASIK) as their primary choice, about 5% raised
>their hands. When asked how many will perform PRK when factors
>indicated (like think cornea), about 95% raised their hands. So it
>would appear that about 5% of refractive surgeons will never do a
>surface ablation, and about 5% will do surface ablation as often as
>possible.
>
>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.

Ragnar Suomi

2004-11-09, 10:08 pm

You should take your theories and present them to the rest of the
world. You seem to be alone with these ideas. Do you smoke crack?

I should have guessed that LASIK caused the downfall of the USSR. GO
LASIK!

On 8 Nov 2004 17:53:32 -0800, gospa68@aol.com (Wizkid) wrote:
[vbcol=seagreen]
>PRK and LASIK destroy the cornea in very different ways. PRK does it
>superficially while LASIK does it structurally. There is a big
>difference much as painting a house is superficial while removing load
>bearing walls is structural. The consequences of the latter are much
>more severe.
>
>In answer to your questions...
>1) I tell patients that come to me for advice (I do not do refractive
>surgery)that we just do not know what the long term effects of cutting
>the flap are...at any depth. Therefore, I do not believe that there is
>any safe minimum. Patients have a right to know this.
>2) We do not know yet. Worst has data out 18 years now. Additionally,
>I think that you may find the whole subject of endothelial cell counts
>one that is still open for more research. Check with the group at
>Emory on this. They, too, will tell you that there is much we do not
>know...very much like the effects of the LASIK flap. Therefore, this
>too should be disclosed to any interested patient.
>3) The patient has a right to know the incidence (based on FDA studies
>as surgeon derived data is mostly non-controlled and self-serving) of
>every possible complication that can affect his/her vision both short
>term and long term. The patient makes the decision in his/her best
>interests not the doctor. Anything short of this is arrogance and
>immoral.
>
>I continue to be amazed at some here who believe that they know what
>is in the patient's best interest. If there is no problem, then just
>let them reach that conclusion. I believe that top-down planning ended
>with the fall of the USSR. It proved to be a failure. It is no less
>true here.
>WK
>

Wizkid

2004-11-14, 11:09 am

It is clear that you missed the course on bio-mechanics!

Genn: "You are making an erroneous analogy. Providing that the cornea
is healthy and at least 250 micron of cornea remains untouched, LASIK
is closer to removing a freestanding room divider, than removing a
load bearing wall (in the narrow confines of ectasia concerns)."

Explain how the LASIK is closer to removing a freestanding room
divider. You cannnot be serious. Are you familiar with hoop stress? If
so, tells us what role it plays in the mechanics of the cornea over
time?

With regards to your other comments, I am not comforted, nor should
any patient be, with your absolute knowledge on the minimum for flaps,
and replacement of p-IOLs. Are you aware of how the 250 micron level
was established? You may not know this...it was not determined
scientifically. There is great uncertainty with all of these
procedures over time. There are no absolutes. Again, I will not ask
you to eat your words in the future...but some angry patients may.
WK

Glenn - USAEyes.org

2004-11-14, 11:09 am

>It is clear that you missed the course on bio-mechanics!

Wrong yet again WizKid. Not only did I attend the course on
biomechanics, but I discussed relevant issues with the course
presenter Cynthia Roberts, PhD.

>Genn: "You are making an erroneous analogy. Providing that the cornea
>is healthy and at least 250 micron of cornea remains untouched, LASIK
>is closer to removing a freestanding room divider, than removing a
>load bearing wall (in the narrow confines of ectasia concerns)."

>Explain how the LASIK is closer to removing a freestanding room
>divider. You cannnot be serious. Are you familiar with hoop stress? If
>so, tells us what role it plays in the mechanics of the cornea over
>time?

Because if performed appropriately with proper ocular health
screening, LASIK does not reduce the structural integrity of the
cornea to a critical level, where fluctuation or ectasia occurs.

>With regards to your other comments, I am not comforted, nor should
>any patient be, with your absolute knowledge on the minimum for flaps,
>and replacement of p-IOLs.

If you would like to debate my information regarding the endothelial
cell loss and the temporary nature of a phakic intraocular lens, I'd
be delighted, so long as you substantiate your opinions with facts.

My information is based upon the data submitted to the FDA,
discussions with the surgeons who were the medical investigators, and
with the inventor of that particular P-IOL.

>Are you aware of how the 250 micron level
>was established? You may not know this...it was not determined
>scientifically.

My understanding (and this from my recollection of a conversation with
a member of the Barraquer family) is that the minimum was originally
an educated guess by Dr. Barraquer of 200 microns, but with trial and
error it was determined this was too low. Subsequent case studies and
later trials determined that 250 is the appropriate minimum (more is
always better). This is not a very pretty way to determine an answer
to a problem, but medicine is sometimes rather messy. I doubt if
anyone in the US would get away with that kind of methodology today.

>There is great uncertainty with all of these
>procedures over time. There are no absolutes. Again, I will not ask
>you to eat your words in the future...but some angry patients may.

And now you start up again with your unfounded "the sky will fall
someday" gloom and doom. I'll stand on the nearly five decades of
case studies, trials, and practical knowledge of millions of lamellar
surgery patients.

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.

Wizkid

2004-11-14, 11:09 am

Great...you are standing on a free standing room divider...while I am
standing on a load bearing wall.

And I am not saying that "the sky is falling." Those are your words
and those of some others on this board. Those who warned of VIOXX's
problem were dealt with the same way you and others deal with those
who warn of ectasia. Remember, the incidence of heart attacks was
relatively small when compared to all that were on the drug. But the
number was large. And Merck is facing bankruptcy as a result. Ectasia
is a sight threatening problem that is irreversible. Patients should
be made aware of it. There are sins of omission around ectasia and
patients are not well informed on its existance.
WK

Glenn - USAEyes.org <glenn.hageleSTOPSPAM@USAEyes.org> wrote in message news:<il05p05luqsrgm067m6qhb33t2c99dl20o@4ax.com>...
>
> Wrong yet again WizKid. Not only did I attend the course on
> biomechanics, but I discussed relevant issues with the course
> presenter Cynthia Roberts, PhD.
>
>
>
> Because if performed appropriately with proper ocular health
> screening, LASIK does not reduce the structural integrity of the
> cornea to a critical level, where fluctuation or ectasia occurs.
>
>
> If you would like to debate my information regarding the endothelial
> cell loss and the temporary nature of a phakic intraocular lens, I'd
> be delighted, so long as you substantiate your opinions with facts.
>
> My information is based upon the data submitted to the FDA,
> discussions with the surgeons who were the medical investigators, and
> with the inventor of that particular P-IOL.
>
>
> My understanding (and this from my recollection of a conversation with
> a member of the Barraquer family) is that the minimum was originally
> an educated guess by Dr. Barraquer of 200 microns, but with trial and
> error it was determined this was too low. Subsequent case studies and
> later trials determined that 250 is the appropriate minimum (more is
> always better). This is not a very pretty way to determine an answer
> to a problem, but medicine is sometimes rather messy. I doubt if
> anyone in the US would get away with that kind of methodology today.
>
>
> And now you start up again with your unfounded "the sky will fall
> someday" gloom and doom. I'll stand on the nearly five decades of
> case studies, trials, and practical knowledge of millions of lamellar
> surgery patients.
>
>
> 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.

wavefront information

2004-11-14, 11:09 am

Both my eyes don't see well after lasik. What does that mean about lasik?

Would prk have been better or what? My flap is 100 to 30um thick. Is that lasik?

Ragnar Suomi <ragnarsuomi@yahoo.com> wrote in message news:<3kp2p0t6mv1klulkh00q3iush63mpq76el@4ax.com>...[vbcol=seagreen]
> I'm glad we agree so much! I don't think anything you said below
> conflicts with my thinking.
> In your last paragraph, you mention that 5% of surgeons will never do
> surface ablation and 95% would do it as factors dictated. Those 5%
> who refuse to do surface ablation are some oddballs. My surgeon does
> PRK as indicated. I asked him how often he has found it preferable to
> do PRK. He said he's done it 3 times out of several thousand.
>
>
> On Mon, 08 Nov 2004 23:02:31 GMT, Glenn - USAEyes.org
> <glenn.hageleSTOPSPAM@USAEyes.org> wrote:
>

Glenn - USAEyes.org

2004-11-14, 11:09 am

LASIK is not Vioxx. Visx is not Merck. For the sake of relevance,
try to stay on point.

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.