I copied this from a post on here a couple years back on the subject, whoever it was from did a good job explaining eye cuttin'
"The difference is probably standard LASIK versus what's loosely
called customized LASIK. Standard LASIK is a remarkable procedure and with a
good candidate it usually gives awesome results. However, customized LASIK is
even better and is well worth the extra cost (typically $500-800 per eye). It's
like this: just as we all have different fingerprints, we all have uniquely
shaped corneas (the clear part of the eye). With standard LASIK those
differences are not taken into account, but with customized LASIK they are.
First, just a little background. LASIK works by re-shaping the cornea in order
to re-focus light onto the retina (think of this as like the film in a camera).
Now when light passes thru any clear media, whether it is a cornea, camera
lens, windshield, etc... some degree of distortion inevitably takes place.
However, it is possible nowadays to measure both the amount, and type, of
distortion using what's called "wavefront analysis." (A detailed
explanation of this is far over my head but suffice it to say it involves
higher-order mathematics to analyze and quantify images. It's the kind of math
that egg-head physicists use to clean up the images from the Hubble Space
Telescope.)
So what customized LASIK does is this: First a precise map of the cornea is
generated using a device called a topographer. This lets the surgeon know the
exact shape and curvature of, say, between 8,000 - 12,000 points (depending on
the topographer) on that cornea. Next, a wavefront analyzer sends an image into
the eye, and by analyzing the degradation in the reflected image as it bounces
back off the retina, it is able to precisely measure the amount and type of
distortion in that individual eyeball. In essence, these devices are
"fingerprinting" the eye.
Now the real magic comes into play. The computer in the laser unit takes the
info from both the topographer and the wavefront analyzer and basically
"tells" the laser how it must re-shape that individual cornea, at
nearly every measured point, in order to eliminate as much distortion as
possible -- i.e. it "customizes" the ablation (laser treatment). For
instance, both Joe Blow and Joe Suck may have a prescription of -4.00. With
standard LASIK, the surgeon would apply equal treatment to both patients, and,
voila, both would likely see very, very well. With customized LASIK, however,
an individual treatment is tailored for each eye -- and the results in terms of
quality of vision are even better. This is where the extra cost comes in, and
trust me, it's well worth it.
As far as surgeons near Lexington, I'm sure while those that others have
mentioned are excellent, I have only dealt personally with the docs at
John-Kenyon -- and with Dr. Asim Piracha in particular. I can tell you that he
is one of the finest anterior segment (the front part of the eyeball) surgeons
in the southeastern United States. He is a fellowship-trained corneal
specialist who also sub-specializes in refractive surgery and I have sent
several of my patients to see him (I live in Paducah). You would be hard-pressed
to find a better LASIK surgeon. Good luck with your procedure.
You're very welcome. A couple of other things to consider FYI...
Others have mentioned using a laser (brand name IntraLase) to create the flap
instead of a microkeratome (basically a glorified, miniaturized door planer),
and they are absolutely correct -- IntraLase is the only way to go. One of the
biggest sources of error with old-school LASIK was a bad flap. With IntraLase
those problems are virtually non-existent -- the lasered flap is much
"cleaner" and has a much more uniform thickness, so therefore distortion
is minimized.
Also, if you are a contact lens wearer you should be out of them a bare minimum
of two weeks if you don't sleep in your contacts and a minimum of three weeks
if you do sleep in them. The longer you can tolerate staying out of them the
better. Success in LASIK depends in large part on having as pristine of a
cornea as possible. The laser works by basically vaporizing corneal tissue in a
precise fashion in order to change its curvature, which in turn changes its
focal power.
Now any contact lens -- even the ultra-breathable ones that are approved for 30
days of continuous wear -- will induce some degree of corneal edema. If this
edema has not resolved by the time of surgery then the treatment will
necessarily be off. So you want your corneas to be as stable and consistent as
possible, and the way to do that is to stay out of your contacts as long as
possible. In this case more is definitely better. The wavefront profiles of
corneas before and after contact lens wear can be dramatic indeed.
Also, if you have chronically dry eyes to begin with then you should have that
treated before surgery. At its core, Dry Eye Syndrome is an inflammatory
process, and this inflammation can have profound effects on corneal topography
-- again, anything affecting the cornea will affect the outcome of LASIK. Any
surgeon worth his/her salt will examine you for dry eye as part of the pre-op
process and will treat accordingly. If whoever you go to doesn't mention it, or
worse, blows it off, go somewhere else."
