Lasik Eyes Surgery - Flap and tear break up time

Author

Flap and tear break up time

crvc@wyoming.com

2005-07-25, 10:38 am

I had LASIK eight years ago which left me with severe night vision
problems. I've tried several types of RGP lenses but cannot tolerate
any of them for more than two hours a day. I have been told I have a
2-3 second tear break up time which is why I can't tolerate the lenses.

A second opinion surgeon is suggesting a flap lift to clean out scar
tissue followed by suturing the flap back down. She says I have high
and low spots on the cornea which is why the tear break up time is so
low. It sort of makes sense to me, visualizing wiping a squeegee across

uneven glass. The squeegee collects water from the high spots but not
the low spots. She is suggesting my eyelids are doing just that.
However, if the fluid remains in the low spots, shouldn't that
momentarily smooth the optical surface, the way RGPs do? I don't see
any differently immediately after a blink.

She
says I cannot have more lasering because I'm 20:20.

I'm hoping the procedure will level the cornea and improve the TBUT.
Is that likely? If so, will that allow longer RGP wear?

TIA

Glenn - USAEyes.org

2005-07-25, 1:36 pm

It would seem to me that improving your tear function would be a side
benefit to the proposed surgery. The primary benefit would be the
removal of scar tissue that would undoubtedly be interfering with your
vision quality.

It is true that an uneven surface can cause dry spots on the cornea,
but I really don't know that the proposed procedure will change the
anterior surface of the cornea enough to make any real difference.
Removing scar tissue, however, should improve vision quality.

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.

Monika

2005-08-05, 9:14 am

I would guess your corneal nerve damage is also a huge factor in
your problems wearing lenses. More surgery won't help that. How
did you end up with scar tissue from LASIK? Did you have DLK?
You may see better if you get rid of that, especially if it is central. I
don't know
how much luck surgeons have taking the flap,which now lives in a crater
essentially where tissue was removed, and making it tight and flat again.
IT was tight and flat when it lived on something protruded and rounding.
Once the LASIK crater is created, the flap settles into the depression
in a wrinkled way. This is why everyone has those Bowman's undulations.
The flap is always wavy.

Hard to say if you would have a smoother surface and improve TBUT.
Has any patient ever been improved by this method?

<crvc@wyoming.com> wrote in message
news:1122301736.654586.76900@o13g2000cwo.googlegroups.com...
>
>
> I had LASIK eight years ago which left me with severe night vision
> problems. I've tried several types of RGP lenses but cannot tolerate
> any of them for more than two hours a day. I have been told I have a
> 2-3 second tear break up time which is why I can't tolerate the lenses.
>
>
>
> A second opinion surgeon is suggesting a flap lift to clean out scar
> tissue followed by suturing the flap back down. She says I have high
> and low spots on the cornea which is why the tear break up time is so
> low. It sort of makes sense to me, visualizing wiping a squeegee across
>
> uneven glass. The squeegee collects water from the high spots but not
> the low spots. She is suggesting my eyelids are doing just that.
> However, if the fluid remains in the low spots, shouldn't that
> momentarily smooth the optical surface, the way RGPs do? I don't see
> any differently immediately after a blink.
>
> She
> says I cannot have more lasering because I'm 20:20.
>
>
> I'm hoping the procedure will level the cornea and improve the TBUT.
> Is that likely? If so, will that allow longer RGP wear?
>
> TIA
>

Glenn - USAEyes.org

2005-08-05, 5:57 pm

"Monica" is either uninformed or simply misinforming.

Not all LASIK flaps develop wrinkles (striae). Patients with a large
amount of myopic (nearsighted, shortsighted) correction and a small
ablation zone are more likely to develop striae, however even in this
instance not every patient develops striae. Furthermore, not every
patient who develops striae has a vision problem due to the presence
of the wrinkles. It is possible for a patient with striae to be
without vision limitation.

Micro-striae do not affect tear film function. Macro-striae may,
however macro-striae is commonly treated and resolved early in
recovery. Any qualified eye physician would be able to see symptomatic
macro and micro-striae in the cornea.

Detailed information about striae and treatment is available at
http://www.complicatedeyes.org/striae.htm

After eight years, subnasal corneal nerves would have returned to
preoperative levels and all corneal sensitivity that is able to return
would have returned. Sensitivity functions can be tested, if believed
to be necessary for proper diagnosis.

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

2005-08-05, 10:56 pm

Monika is stretching here.

Lasik crater? Bowmans undulations? The flap is always wavy? Nothing
remotely like this happens in the line of sight. That's why they cut
the flap much wider than the ablation zone.

SErebel

Adam

2005-08-06, 10:55 pm

Sorry SErebel, you are wrong again as usual. Bowman's undulations are
throughout the flap. The flap is the same size
as the tissue underneath when it is cut, but when the laser removes tissue
underneath the roundness
is removed and the flap settles into a depression (crater). The edges are
now wider than the cut area and hang over.
This makes the big red outer ring you see on topography elevation maps and
contributes to spherical aberration.

If you go for an artemis scan, which is an ultrasound that images every
layer of your eye with an accuracy of one micron
you can easily see that your bowman's wrinkles are central and that you have
'flap hangover' extending past the edges of
your 'crater'.

Yep, I have pictures of all that.

"serebel" <serebel@aol.com> wrote in message
news:1123294789.099948.304180@f14g2000cwb.googlegroups.com...
> Monika is stretching here.
>
> Lasik crater? Bowmans undulations? The flap is always wavy? Nothing
> remotely like this happens in the line of sight. That's why they cut
> the flap much wider than the ablation zone.
>
> SErebel
>

serebel

2005-08-06, 10:55 pm

Adam wrote:
> Sorry SErebel, you are wrong again as usual. Bowman's undulations are
> throughout the flap. The flap is the same size
> as the tissue underneath when it is cut, but when the laser removes tissue
> underneath the roundness
> is removed and the flap settles into a depression (crater). The edges are
> now wider than the cut area and hang over.
> This makes the big red outer ring you see on topography elevation maps and
> contributes to spherical aberration.
>
> If you go for an artemis scan, which is an ultrasound that images every
> layer of your eye with an accuracy of one micron
> you can easily see that your bowman's wrinkles are central and that you have
> 'flap hangover' extending past the edges of
> your 'crater'.
>
> Yep, I have pictures of all that.
>
>

The way you and Monika portray this is to say the least exaggerated.
All this happens and yet people can see just fine.

SErebel

Ragnar

2005-08-07, 9:07 am

corneal nerve damage.. whoo boy. You are talking about the regrowth
of 33 to 66% of the nerve fibers - and those nerve fibers are so tiny
that they are invisible to the naked eye. If you could see them, they
would look like a few strands of dust a few millimeters long with
virtually no width.

On Fri, 5 Aug 2005 08:16:11 -0400, "Monika" <Monika@nospam_aol.com>
wrote:

>I would guess your corneal nerve damage is also a huge factor in
>your problems wearing lenses. More surgery won't help that. How
>did you end up with scar tissue from LASIK? Did you have DLK?
>You may see better if you get rid of that, especially if it is central. I
>don't know
>how much luck surgeons have taking the flap,which now lives in a crater
>essentially where tissue was removed, and making it tight and flat again.
>IT was tight and flat when it lived on something protruded and rounding.
>Once the LASIK crater is created, the flap settles into the depression
>in a wrinkled way. This is why everyone has those Bowman's undulations.
>The flap is always wavy.
>
>Hard to say if you would have a smoother surface and improve TBUT.
>Has any patient ever been improved by this method?
>
>
><crvc@wyoming.com> wrote in message
>news:1122301736.654586.76900@o13g2000cwo.googlegroups.com...
>