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Registered: 05-2005
Posts: 816
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Wavefront challenge fails, high order aberrations induced, usually residual prescription


TAKE THE WAVEFRONT CHALLENGE
If you are considering wavefront-custom LASIK, take the wavefront
challenge (nomal virgin eyes only). Here's how:

Ask the surgeon to provide you with a copy of your pre-op wavefront
scans (these are the scans that measure those "small imperfections" in
your vision, known as higher order aberrations).


Wait 3 months for your eyes to stabilize, then have the surgeon repeat
the wavefront scan at the same pupil diameter of the pre-op scan.


Compare the before and after wavefront scans. Did the higher order
aberrations decrease as they claimed? If not, wavefront did not do what
they say it does. Don't be fooled by the total RMS numbers -- that
includes all that myopia and regular astigmatism they treated -- so of
course the total RMS will be lower.


Be sure to have a refraction done at 6 months, too. Does it read plano,
both eyes (no sphere, no cylinder)? If not, wavefront was not even
successful at correcting the error that glasses can correct. Any
refraction other than plano in both eyes means your vision can be
improved with glasses following wavefront custom LASIK. This is usually
the case.


Read the labeling:
http://www.fda.gov/cdrh/LASIK/lasers.htm


Wavefront does not reduce higher order aberrations (small imperfections
in your vision). It increases them!


So if your surgeon claims that wavefront will give you better vision
than you have with glasses, have him explain why the "small
imperfections" increased instead of decreased.


The Challenge: Is there even one patient, just one, who can show their
higher order aberrations decreased following wavefront-custom LASIK
(primary surgery)? Scour the earth to find one patient for whom
wavefront ACTUALLY WORKED.


Note: If your pupils are larger than 6mm, ask to have the scans taken
at your scotopic pupil diameter.


Ace's comments: I found this in the archieve search and was amazed about the limitations of lasik. Not only does wavefront(and all forms of laser surgury) induce aberrations, they often cant even get you to plano! Granted if you end up very close to plano, its not a big deal unless you are very picky with perfect vision. I have read the successful lasik testimonals off a surgeon's website and most of the 200+ testimonals show that post lasik the prescription is a quarter or half diopter sphere and/or cylindar shy of plano. Way too low for enhancement and also UCVA is 20/20 to 20/25 which in other words is very good, even if not 100% perfect, but then nothing in life is perfect. Lasik reduces dependancy on glasses, many people still need or want or prefer to wear glasses still for stuff like driving, movies, reading, etc. Ending up a bit undercorrected isnt a big deal if you are middle age(and older) as this will reduce your dependancy on those dreaded readers.

As for high order aberrations, I already know all forms of laser(and refractive) surgury induces/increases aberrations. The flap alone increases tons of aberrations. An oblate(flattened) cornea increases lots of spherical aberrations. The large broadbeam 6mm laser or the smaller .5mm flying spot laser is still far larger than the aberrations which measure from a few microns to less than one micron! To really target each individual aberration, the laser would need to be no larger than a micron in size! All todays lasers can do is reduce your prescription and "try" not to induce too many aberrations. Tradational lasik greatly increases your aberrations. Wavefront minimizes the problem by "reducing" the amount of aberrations that are induced. Your RMS(root mean square) of high order aberrations will increase. Large pupil patients are affected much more. Nearly all lasik patients, especially non-wavefront will notice some quirks with their vision. You may notice at night everything appears darker and more distinct and lights have glare, halos, starbursts or other "effects" Your contrast has been reduced. Ghosting and smearing is also possible. On the bright side, 90% are happy with lasik because their dependancy on glasses is reduced, they are much closer to plano and arent super picky about their new aberrated eyes and dont mind slight compromises to their visual quality.
7/17/2006, 6:07 pm Link to this post Send Email to Myope5   Send PM to Myope5
 


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