Lasik Eyes Surgery - prk vs lasik & are the claims possible?

Author

prk vs lasik & are the claims possible?

glassessinceage7

2005-11-11, 3:23 pm

I recently visited two eye surgeons in the San Francisco Bay Area to
look at the possibility of having lasik surgery. I am nearsighted with
astigmatism and my correction for both eyes is just under 6. I'm 49
years old and my prescription has been very stable over the last years.

I liked both doctors I met but they had different reactions to my eyes.
One doctor, Scott Hyver, declared after the examination that he would
not perform Lasik on me because of the shape of my cornea but would
recommend PRK instead. The other doctor, Ella Faktorovich, said that
any problems Hyver might have worried about wouldn't be an issue for
her because she uses Intralase instead of the microkeratome used by
Hyver. Because of this difference, she would perform Lasik.

So I have two questions: Based on the (admittedly) limited information
I'm providing-I don't fully understand the issues with my
cornea-do the different reactions of the doctors to my eyes seem
reasonable based on the technologies they use? Secondly, the
representative from Faktorovich's office volunteered that in the 8000
(!) surgeries the doctor has done in the last 2 years, 100% of patients
have achieved 20/20 or better. This seems, well, too good to be true.
Is this possible?

I failed to ask Dr. Hyver's representative the expected success rate
for my eyes with the PRK surgery, but I intend to.

I have been reading this site a bit and am particularly interested in
Glenn Hagale's reaction to Dr. Faktorovich's success claim, since
she is a member of the Council for Refractive Surgery Quality
Assurance. Perhaps he could check with her and have this claim
confirmed. Although Faktorovich's cost is substantially higher, I
would be inclined to go with her if she's really that successful. I
forgot to mention that Faktorovich only does wavefront, which might
also be a factor in her success.

Thanks in advance for any thoughts on this.

ycdbsoya

2005-11-11, 3:23 pm

1st of all, if anyone tells you they get 100% 20/20, run - do not walk
- from their office. That is total BS.

2nd, since you are 49, consider monovision as a means to address your
impending presbyopia.

3rd, I would get to the bottom of the "shape of the cornea" issue. You
may have something else at play here, such as form fruste keratoconus,
a thin cornea or irregular astigmatism that would be LASIK
contraindications. The following is a cutnpaste regarding PRK.

"Dr. Salz, codirector of refractive surgery research at Cedars-Sinai
Medical Center in Los Angeles, cites several situations where PRK is,
or should be, considered as the preferred procedure:

=B7 Recurrent erosion syndrome. In patients with a history of recurrent
corneal erosion, said Dr. Salz, PRK is preferred to LASIK, as the
microkeratome used in a LASIK procedure cuts across the corneal
erosions, increasing the risk of complications such as diffuse lamellar
keratitis and epithelial ingrowth.

=B7 Visible map dot dystrophy. Dr. Salz also warned against performing
LASIK on patients with an abnormal epithelium such as visible map dot
dystrophy because of the risk of complications.

=B7 Form fruste or frank keratoconus. "LASIK is contraindicated in
both form fruste or frank keratoconus," Dr. Salz said. However, some
surgeons feel that PRK can be considered when the patient gives special
informed consent about the possible increased risk of irregular
astigmatism, progression of the ectasia, decrease in predictability,
increased risk of haze and increased risk of loss of best corrected
visual acuity. "In my practice, we have performed cases up to -10 D
where LASIK was contraindicated in these patients and they have done
well with PRK because we are not doing the procedure under the flap."

=B7 Cornea problems. PRK may be indicated when the cornea is too thin
for the amount of correction needed. In highly nearsighted patients,
Dr. Salz explained, the cornea may not be thick enough to leave 250
microns of tissue below the flap in the LASIK bed. In his practice, he
offers PRK instead of LASIK in cases where preoperative calculations
indicate corneal thickness may be inadequate for safe LASIK.

Other cornea candidates are those that are flat or steep to the point
that the risk of a flap complication with LASIK is high, said Dr.
Wilson.

=B7 Large pupils. Another indication for PRK is when the pupils are too
large for standard ablation diameter, and increased depth of larger
ablation diameter means corneal thickness is inadequate for safe LASIK,
even with low corrections. Interestingly, some of the recent laser
manufacturers have upgraded their equipment to perform LASIK on larger
zones and larger blend zones. For example, two years ago, an
8-millimeter pupil would not be a candidate for LASIK because of the
increased risk of postoperative glare. However, some lasers can
accommodate this pupil size today, and these eyes may be amenable to
LASIK. In general, however, PRK may still be preferred for larger pupil
size. (For a discussion of pupil size and LASIK, see next month's
EyeNet.)

=B7 Safety. Some patients may choose PRK over LASIK for low corrections
to reduce the risk of complications or because they engage in high-risk
activities such as law enforcement or professional sports that could
jeopardize the LASIK flap.

=B7 Military regulations. Military regulations for pilots may exclude
LASIK but accept PRK.

=B7 Dry eye. Dr. Wilson also noted that eyes with low correction but
mild or moderate dry eye might be candidates for PRK, as they would be
at risk of developing severe dry eye with LASIK."

Finally, there are several excellent doctors up in the Bay Area. I
would steer you toward Stanford's docs. You'll get your better results
in a non-profit.

Glenn - USAEyes.org

2005-11-11, 3:23 pm

With the limited information available I am required to make some
assumptions, but I think I understand what the doctors are talking
about.

A LASIK flap created with a mechanical microkeratome that uses a steel
blade is meniscus in shape. It has a tapered edge, thick mid
periphery, and thinner center. A LASIK flap created with a femtosecond
laser microkeratome is planar in shape. It has an even thickness
throughout and the edges can be made to just about any shape desired,
even at a right angle. This creates a "manhole cover" flap.

If the cornea is unusually steep or unusually flat, a mechanical
microkeratome can create a flap that is too thick by going too deep
into the cornea or too thin and break the surface in the thinner
center of the flap (buttonhole flap). Because of the increased
accuracy of the depth of a flap created with a femtosecond laser plus
the even thickness of the flap throughout, IntraLASIK can sometimes be
safer than LASIK with a mechanical microkeratome.

I am a big fan of surface ablation techniques, which include PRK,
LASEK, and Epi-LASIK. In fact, I personally had PRK based upon the
recommendation of my surgeon. Study after study have shown that a
wavefront-guided PRK provides a better outcome in the long term than
conventional ablation and wavefront-guided LASIK. If anything, I am
biased toward surface ablation.

That said, I can certainly understand the advantage of LASIK over
surface ablation. The functional vision recovery is almost immediate,
whereas in PRK you won't be able to see much of anything for several
days and will have "functional fuzzy" vision for several weeks with
sharp clarity not arriving for weeks to a couple of months. LASIK is
virtually painless, where there can be significant discomfort with a
surface ablation technique. LASEK and Epi-LASIK are supposed to limit
the discomfort, but there is always some.

New studies are showing that IntraLASIK with a femtosecond laser are
almost at or equal to the long-term outcomes of PRK. There are only
two studies that affirm this, but it is an indication that IntraLASIK
may be a better choice than LASIK and may be almost as good as PRK.
These studies are from very well respected surgeons, but I'd like to
see more studies in this regard before equating IntraLASIK with PRK
outcomes just yet.

As you undoubtedly know from our website, anytime a doctor makes
claims that seem too good to be true you want confirmation and to
question the validity of the claim. Although I have no independent
information that can prove or disprove Dr. Faktorovich's claim, there
are at least four reasons why 100% 20/20 may be an accurate statement,
but not quite the whole story.

Reason 1: Snellen 20/20 is a limited method of measuring vision. It
provides vision "quantity" based upon known letters of the alphabet,
black on white, sharp edges, and in a controlled lighting environment.
Even if the letters are slightly blurred or there are multiple images,
if you can guess the 20/20 line, you are deemed 20/20. Snellen does
not account for the variable lighting, color, and contrast of the real
world. Snellen is the standard of the industry, but it is a limited
standard.

Reason 2: Patient Selection. The best way to get poor results is to do
surgery on patients that should never have surgery. The best way to
get good results is to only select patients who are well within the
margin for error.

Reason 3: Snellen 20/20 does not consider peripheral complications.
Someone may have truly excellent vision, but only if using artificial
tears every hour on the hour to resolve temporary LASIK induced dry
eye. Someone may have excellent vision in the controlled lighting of a
doctor's office, but have haloes or starbursting when attempting to
drive at night.

Reason 4: Custom Wavefront Guided Ablation: In the FDA trials and in
the real world, wavefront-guided ablations with both surface ablation
and LASIK/IntraLASIK provide outcomes that can only be described as
remarkable. Studies are often presented with a 90% 20/15 outcome, but
then you need to refer back to reasons number one, two, and three.

Dr. Faktorovich is certified by our organization and I know her
reasonably well. I don't think she would fudge on her numbers, but
I am always uncomfortable when anyone makes statements like this.
There are reasons that she can say she has 100% 20/20. I've provided
four of them. I would prefer she not make this claim even if it is
true because even if they are absolutely accurate and able to be
proven, such claims can cause unreasonable patient expectations

If any doctor makes such claims, it puts in the mind of the public
that LASIK is perfect every time. It is not. Even if due to the
factors above (and others) a doctor actually does achieve 20/20 with
every patient, there would have been many members of the general
public who would have been excluded. Those folks may be under the
misconception that LASIK is 100% perfect. That is a dangerous
misconception.

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.

glassessinceage7

2005-11-11, 3:23 pm

Thank you both very much for your candid and helpful input on this. I
can confirm that the problem with my cornea, I believe, is that it is
very steep. I remember that years ago I tried wearing contacts but gave
up eventually because of my cornea's shape.

I experimented with monovision at Dr. Hyver's office and was fine up
close but didn't like the distance bluriness.

I agree that Dr. Faktorovich might do better to claim something less
than 100% 20/20; 99% somehow would seem more reasonable. I do think she
runs an outstanding office and and is an excellent surgeon; also, she
definitely screens her patients carefully.

I will do a little more research before making a decision on this but
many thanks again for you help!

Glenn - USAEyes.org

2005-11-11, 3:23 pm

The thing about monovision is that you can know if you like it right
away, but it takes about three weeks to know for sure that you hate
it. The brain does not know how to "switch eyes" for distance or near
vision the moment you put in the contact.

http://www.usaeyes.org/faq/subjects/monovision.htm

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.

Ragnar

2005-11-11, 3:23 pm

8000 surgeries with 100% at least 20/20 is a bit far fetched... 99%
would be reasonable though. I'm sure that surgeon had a few dozen
20/40s

I am not in the mood today to get into the PRK thing again. Just keep
in mind that your PRK surgeon is offering a lower price. Frankly, it
doesn't take a very skilled surgeon to do PRK. The patient is the one
that suffers a bit for making the prk plunge.

For those interested in PRK instead of LASIK, they might also like
silver/mercury amalgam fillings in their teeth instead of bonding, and
might prefer amputated limbs to vein/artery grafts.

On 4 Nov 2005 08:11:44 -0800, "glassessinceage7"
<winerystuff@gmail.com> wrote:

>I recently visited two eye surgeons in the San Francisco Bay Area to
>look at the possibility of having lasik surgery. I am nearsighted with
>astigmatism and my correction for both eyes is just under 6. I'm 49
>years old and my prescription has been very stable over the last years.
>
>I liked both doctors I met but they had different reactions to my eyes.
>One doctor, Scott Hyver, declared after the examination that he would
>not perform Lasik on me because of the shape of my cornea but would
>recommend PRK instead. The other doctor, Ella Faktorovich, said that
>any problems Hyver might have worried about wouldn't be an issue for
>her because she uses Intralase instead of the microkeratome used by
>Hyver. Because of this difference, she would perform Lasik.
>
>So I have two questions: Based on the (admittedly) limited information
>I'm providing-I don't fully understand the issues with my
>cornea-do the different reactions of the doctors to my eyes seem
>reasonable based on the technologies they use? Secondly, the
>representative from Faktorovich's office volunteered that in the 8000
>(!) surgeries the doctor has done in the last 2 years, 100% of patients
>have achieved 20/20 or better. This seems, well, too good to be true.
>Is this possible?
>
>I failed to ask Dr. Hyver's representative the expected success rate
>for my eyes with the PRK surgery, but I intend to.
>
>I have been reading this site a bit and am particularly interested in
>Glenn Hagale's reaction to Dr. Faktorovich's success claim, since
>she is a member of the Council for Refractive Surgery Quality
>Assurance. Perhaps he could check with her and have this claim
>confirmed. Although Faktorovich's cost is substantially higher, I
>would be inclined to go with her if she's really that successful. I
>forgot to mention that Faktorovich only does wavefront, which might
>also be a factor in her success.
>
>Thanks in advance for any thoughts on this.

Just Jack

2005-11-11, 3:23 pm

Actually Glen, with monovision, I think it's the opposite. It could take you
3 to 4 weeks, or even months to get used to it before you like it.

I've known people who "hated" it from day one, and therefore really refused
to give it a chance. To get used to it.

Either way though, you're right in that it really takes some time getting
used to it.

I wore monovision contacts for 10 years before my LASIK surgery. I can't say
I ever "loved" it, but it sure beat the hell out of glasses. People who
attempt it need to realize from the get go that it's not perfect. For either
distance or reading. And if you let yourself, you can at anytime be aware of
the difference.

Also, I think, but I don't know for sure, that the greater the difference
between your reading and distance eyes, the more difficult it is to adapt to
it. At least that's been my experience as my reading vision gradually
slipped during my 40's.

I'd say give it a few months.

"Glenn - USAEyes.org" <glenn.hageleSTOPSPAM@USAEyes.org> wrote in message
news:4tnnm1931pjhuctb7gnttu6ot0ei3b1rrj@4ax.com...
> The thing about monovision is that you can know if you like it right
> away, but it takes about three weeks to know for sure that you hate
> it. The brain does not know how to "switch eyes" for distance or near
> vision the moment you put in the contact.
>
> http://www.usaeyes.org/faq/subjects/monovision.htm
>
> 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.

Glenn - USAEyes.org

2005-11-11, 3:23 pm

Perhaps my statement was not artfully written, but we agree Jack.

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.

serebel

2005-11-11, 3:23 pm

ycdbsoya wrote:
> 1st of all, if anyone tells you they get 100% 20/20, run - do not walk
> - from their office. That is total BS.

totally agree with this one.

> 2nd, since you are 49, consider monovision as a means to address your
> impending presbyopia.

try monovision contacts first to see if you adapt to it.

>
> 3rd, I would get to the bottom of the "shape of the cornea" issue. You
> may have something else at play here, such as form fruste keratoconus,
> a thin cornea or irregular astigmatism that would be LASIK
> contraindications. The following is a cutnpaste regarding PRK.

At age 49 with a stable refraction for years as you state you do not
have keratoconus.

You could try a third opinion to aid in your decision.

SErebel

Glenn - USAEyes.org

2005-11-11, 3:23 pm

Normally, keratoconus will present itself before the fourth decade of
life. At 49, he is pretty much out of the woods.

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.

ycdbsoya

2005-11-11, 3:23 pm

Speaking in absolutes is a dangerous thing.

Keratoconus can develop at any time, but most commonly in teens/early
adulthood. Refractions in KC can be stable for years, and there may
also be a gradual onset and consequent scrip change in younger years
that is misdiagnosed as myopia with an astigmatic component,
particularly if nothing else presents and there is no family history.
Evidence of stable refractions are not an acceptable method to
determine the existence of KC.

Obtaining a topography and pachymetry is the way to confirm it or rule
it out. Seven, please let us know what you find out and/or please
clarify the corneal issues.

CatmanX

2005-11-11, 3:23 pm

A few things worth noting:

1) at 49 yo, refractive lensectomy is worth considering. Multifocal
implants mean no or limited glasses afterwards. If astigmatism is
present, AK can be done simultaneously.

2) PRK has as good or marginally better outcomes at 12 months out. PRK
has more discomfort over the first week, but once healed has very good
optics. There is no real disadvantage of PRK except for healing time.
Lasik is preferred as you get back to work quicker with less pain, but
this does not necessitate better long-term outcomes.

dr grant

Ragnar

2005-11-11, 3:23 pm

You should post this in the keratoconus forum.
As has been pointed out several times in this newsgroup, the incidence
of keratoconus in post lasik patients is actually a bit LOWER than
that of the general population . That isn't because LASIK prevents
keratoconus, it is because lasik patients are generally pre-screened
so that people with very troublesome eyes to begin with are not
treated with lasik. On the other hand, there is no reason to fear
that having lasik done is going to increase one's risk of keratoconus.

On 7 Nov 2005 09:02:42 -0800, "ycdbsoya" <the_boydstons@hotmail.com>
wrote:

>Speaking in absolutes is a dangerous thing.
>
>Keratoconus can develop at any time, but most commonly in teens/early
>adulthood. Refractions in KC can be stable for years, and there may
>also be a gradual onset and consequent scrip change in younger years
>that is misdiagnosed as myopia with an astigmatic component,
>particularly if nothing else presents and there is no family history.
>Evidence of stable refractions are not an acceptable method to
>determine the existence of KC.
>
>Obtaining a topography and pachymetry is the way to confirm it or rule
>it out. Seven, please let us know what you find out and/or please
>clarify the corneal issues.

Ragnar

2005-11-11, 3:23 pm

Your comments below are fascinating, even if t hey are wrong.

Basically, ablating the epithelium - forcing it to regenerate, is a
bad thing. HOWEVER.. if someone has a severe defect in their
epithelium, tear, abrasion, etc. Then it makes sense to do prk.

On 7 Nov 2005 12:54:48 -0800, "CatmanX" <grantm@connexus.net.au>
wrote:

>A few things worth noting:
>
>1) at 49 yo, refractive lensectomy is worth considering. Multifocal
>implants mean no or limited glasses afterwards. If astigmatism is
>present, AK can be done simultaneously.
>
>2) PRK has as good or marginally better outcomes at 12 months out. PRK
>has more discomfort over the first week, but once healed has very good
>optics. There is no real disadvantage of PRK except for healing time.
>Lasik is preferred as you get back to work quicker with less pain, but
>this does not necessitate better long-term outcomes.
>
>dr grant

ycdbsoya

2005-11-11, 3:23 pm

Raggie, the pt. has not yet had RS. Please reread the posts.

Also, please qualify why ablating the epi is "a bad thing," and also
clarify why CatmanX's statements are wrong. For example, a pt. with a
thin cornea could have PRK instead of LASIK, thus providing the pt.
with the benefits of RS that would otherwise not have occurred. How is
that "a bad thing?"

CatmanX

2005-11-11, 3:23 pm

Grant's statement is not wrong, poor old raggypoo just does not like it
when I say anything. The point here is PRK is a perfectly valid option
and epithelial regeneration will occur whether or not it is ablated.
The epithelium will replace itself every 7 days, so PRK simply denudes
the surface temporarily.

Also, KC is not going to happen at this age, but the possibility of
ectasia is probably the reason the surgeon suggested PRK over Lasik.

dr grant

Ragnar

2005-11-11, 3:23 pm

Any competent ophthalmologist or optometrist knows that removing the
epithelium is a last resort. That is why the LASIK procedure was
developed to begin with.

And frankly, Frank, you are not worthy of a reply.

On 8 Nov 2005 08:35:47 -0800, "ycdbsoya" <the_boydstons@hotmail.com>
wrote:

>Raggie, the pt. has not yet had RS. Please reread the posts.
>
>Also, please qualify why ablating the epi is "a bad thing," and also
>clarify why CatmanX's statements are wrong. For example, a pt. with a
>thin cornea could have PRK instead of LASIK, thus providing the pt.
>with the benefits of RS that would otherwise not have occurred. How is
>that "a bad thing?"

ycdbsoya

2005-11-11, 3:23 pm

Dumbass, you just replied to me. It's interesting that you don't even
realize how stupid you are, and you played directly into my hands. It
would have been best to ignore it, but you just had to respond. Can't
control yourself, can you my little poopy-pants toddler?

The reason is: you don't know, you have no idea what you're talking
about but you keep on laying down those hash marks. You have zero cred
and are working on negative numbers.

No, Ragweed, LASIK was developed for another reason. Every competent
opth and opt knows why that is. Ask them, you might actually learn
something..

Glenn - USAEyes.org

2005-11-11, 3:23 pm

That's pretty harsh Frank, but you and Ragnar have brought up an
interesting point.

Removal of the epithelium (outermost layer of cells on the cornea)
causes vision to become very poor because about 50 microns of cornea
refraction power are now gone and the underlying surface does not
benefit from the smoothing properties of the epithelium. Additionally,
removal of the epithelium hurts. No, it hurts a lot.

The corneal epithelial cells are the fastest reproducing cells in the
human body, but while they multiply and thicken, vision is very poor.
And the eyes hurt...a lot.

When the excimer laser was applied to eye surgery, the resulting PRK
procedure required the removal of the epithelium, allowing the laser
to remove tissue from the underlying cornea. This meant that vision
would be poor for several days to weeks, and the eyes would hurt. You
guessed it...a lot.

Another problem with PRK was that the wound healing response would
cause opaque cells to congregate and form in the cornea. This caused
haze that could permanently reduce vision quality. Well, at least the
haze didn't hurt.

I very clever ophthalmologist realized that if the surgery took place
in the center of the cornea, the epithelium would not need to be
removed and the wound response would be different. By applying the
laser energy under a flap of corneal tissue, there was an almost
instant vision recovery, virtually no corneal haze, and (voila)
almost no pain.

Although Ragnar's statement that removal of the epithelium would be
the last thing a doctor would want to do, that really depends upon
what is trying to be accomplished. No pain, instant vision recovery,
and little chance of haze are all good things, but sometimes these
cannot be provided AND get the desired long-term result. This is why
the surface ablation techniques of PRK, LASEK, and Epi-LASIK have held
some popularity and will undoubtedly always have an appropriate place
in refractive surgery.

The described LASEK with a ultra-thin stromal flap is attempting to
get the best out of both worlds. I think more study by multiple
physicians will determine if this is correct. I know that many doctors
are moving toward a thinner flap (especially those using the Intralase
femtosecond laser) because there is a perception of less LASIK induced
temporary dry eye and because there is more untouched tissue, but a
flap is still a flap no matter how thick or thin.

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.

ycdbsoya

2005-11-11, 3:23 pm

Glenn, verbally defecating children like Rags need to be spanked.

Re: LASIK, you got it Glenn. LASIK was/is a marketing tool that
simplified RS, reduced discomfort and had rather immediate results. The
surface ablation techniques - while providing better long run outcomes
- were far more onerous for patients to undergo. I had some pain, but
the itching was horrible...I wanted to puck out the orb and scratch it
all over, and I only had a few mics removed.

Unfortunately, LASIK became the most popular form of RS even though it
has some pretty serious drawbacks and the long term effect on eye
health remains relatively unknown. Those drawbacks include compromised
corneal integrity, transient and permanent dry eye, permanently reduced
efficacy of corneal nerve function. But, hey, it's easy...a 20 minute
miracle.

Glenn - USAEyes.org

2005-11-11, 3:23 pm

While the complications you mentioned do exist and can be just as bad
as you describe, they are relatively rare - by medical standards. It
is always important to couple the possibility of a complication with
the relative probability. There are a gazillion things that possibly
can kill us every day, but the probability of seeing tomorrow is
pretty good.

You can call the shift of refractive surgery from PRK to LASIK as a
"marketing tool", but I believe most would call it an improvement.
Keep in mind that the results of PRK today - which tend to be better
long-term than LASIK - are not the results that were able to be
attained when LASIK was developed. New technology, techniques, and
understanding all contribute to PRK's long-term advantage. This is one
of the reasons surface ablation is making a mini-comeback.

As much of a fan as I am for surface ablation like PRK, LASEK, and
even Epi-LASIK, I can really understand the motivation for a patient
to select LASIK. The cost of lost income for the days to weeks after
PRK can make the entire process out of reach. This is the land of
instant results. LASIK is a natural.

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.

Ragnar

2005-11-11, 3:23 pm

I don't know why you bother replying to frank.

Anyway, I would just add a few comments. I believe the epithelium is
actually more like 60 microns not 50.. but that is being picky. Those
cells do regenerate faster than any other cells, but they don't
regenerate as orderly as the original epithelium. It's like the
difference between a patch of skin, and a patch of scar tissue.

The doctors going for the ultra thin flaps are the intralase people.
The microkeratome really doesn't allow for ultrathin flaps. And the
intralase method wouldn't even exist if the microkeratome
manufacturers were not so greedy with the prices of their overpriced
equipment. The intralase is used primarily as a marketing tool.

On Wed, 09 Nov 2005 21:03:00 GMT, Glenn - USAEyes.org
<glenn.hageleSTOPSPAM@USAEyes.org> wrote:

>That's pretty harsh Frank, but you and Ragnar have brought up an
>interesting point.
>
>Removal of the epithelium (outermost layer of cells on the cornea)
>causes vision to become very poor because about 50 microns of cornea
>refraction power are now gone and the underlying surface does not
>benefit from the smoothing properties of the epithelium. Additionally,
>removal of the epithelium hurts. No, it hurts a lot.
>
>The corneal epithelial cells are the fastest reproducing cells in the
>human body, but while they multiply and thicken, vision is very poor.
>And the eyes hurt...a lot.
>
>When the excimer laser was applied to eye surgery, the resulting PRK
>procedure required the removal of the epithelium, allowing the laser
>to remove tissue from the underlying cornea. This meant that vision
>would be poor for several days to weeks, and the eyes would hurt. You
>guessed it...a lot.
>
>Another problem with PRK was that the wound healing response would
>cause opaque cells to congregate and form in the cornea. This caused
>haze that could permanently reduce vision quality. Well, at least the
>haze didn't hurt.
>
>I very clever ophthalmologist realized that if the surgery took place
>in the center of the cornea, the epithelium would not need to be
>removed and the wound response would be different. By applying the
>laser energy under a flap of corneal tissue, there was an almost
>instant vision recovery, virtually no corneal haze, and (voila)
>almost no pain.
>
>Although Ragnar's statement that removal of the epithelium would be
>the last thing a doctor would want to do, that really depends upon
>what is trying to be accomplished. No pain, instant vision recovery,
>and little chance of haze are all good things, but sometimes these
>cannot be provided AND get the desired long-term result. This is why
>the surface ablation techniques of PRK, LASEK, and Epi-LASIK have held
>some popularity and will undoubtedly always have an appropriate place
>in refractive surgery.
>
>The described LASEK with a ultra-thin stromal flap is attempting to
>get the best out of both worlds. I think more study by multiple
>physicians will determine if this is correct. I know that many doctors
>are moving toward a thinner flap (especially those using the Intralase
>femtosecond laser) because there is a perception of less LASIK induced
>temporary dry eye and because there is more untouched tissue, but a
>flap is still a flap no matter how thick or thin.
>
>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.

Glenn - USAEyes.org

2005-11-11, 3:23 pm

I'm not so sure about your concerns regarding epithelium regeneration.
I've seen detailed microscopic photographs of regenerated epithelium
and it appears to be exactly the same as preop, additionally removal
and renewal of epithelium is a therapeutic treatment for many maladies
that affect the eyes.

It is much more difficult to reliably get an ultra thin flap with a
mechanical microkeratome than with a femtosecond laser microkeratome.

My personal response to your statement that Intralase femtosecond
laser for flap creation is primarily a marketing tool is exactly the
same as my response to Frank's comment that LASIK is little more than
a marketing tool: Many would consider both to be an improvement.

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.

Glenn - USAEyes.org

2005-11-21, 5:59 pm

This may help confirm the claims made by Dr. Faktorovich's office
regarding her outcomes.

At the Refractive Surgery Subspecialty Meeting at the American Academy
of Ophthalmology meeting this year, Dr. Faktorovich presented data
with Intralase/Wavefront that showed 100% 20/20 or better at one month
postop, 97% at 3 months, and 93% at 6 months. At one year, 97% of
Wavefront/Intralase patients saw 20/20 or better.

I hope that clarifies your concern a bit, and of course the best
source for clarification is your doctor.

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.