Naturally Elevated HOA (Higher Order Abberation)

[Victor]

Hello All,

I am posting in this forum after a long time.

I have severe astigmatism (Pure Cylindrical Power (Right eye -2.75 x 20 degree and -2.5 x 160 degree) and i see a lot of ghosting and star bursting in low light conditions.

I had been to a lasik doc (The best we have in our country) where they conducted wavescan and pachymetry of my cornea and told me that my HOA(s) are elevated and that i have a HOA of .56 microns in right eye and .43 microns in the left. The coma and trefoil values of the Zernike polynomials were highly elevated, however the doctor ruled out Keratoconus.

Other thing i would like to mention is the fact that wavescan is an amazing diagnostic tool, the pattern it made for the distortion is exactly what i see in dim light, seeing which i was thrilled that at least this technology can tell the doctor what the patient sees without the need of the patient telling the doctor what kinda distortions are seen by him.

The doctor however promised that lasik can reduce HOA(s) but cannot do away with it completely and said that some residual coma and trefoil will remain, also she said how my eyes react to the lasik will dictate the final outcome.

I am surprised that this doctor promised reduction in HOA, in spite of the fact that Lasik induces more HOA(s) at root mean square values (RMS) than they reduce it, so how come the coma and trefoil values be done away with.

Also I've learned from this site that none of lasers are approved by the FDA to treat Higher Order Abberations (HOA), so is the promise being made here is utterly false ?

[Victor]

Requesting Glenn's insight on this.

Can lasik help in my case ?

[LasikExpert]

The claim by the doctor to lower HOA is not necessarily false.

If the HOA are elevated prior to surgery, and if they are caused or exacerbated by high astigmatism, it is possible, even probable, that some of the HOAs will be reduced closer to normal levels after surgery.

[Victor]

Hi Glenn,

Thanks for your insight.

My eyes have a very high cylinder power, with minimal sphere of +0.5 in both the eyes.

I am very skeptical of the lasik coupling effect.

Will my eyes have farsightedness after lasik due to coupling effect.

Please suggest.

[LasikExpert]

The coupling effect of astigmatic correction with Lasik should not be a problem because you have more than enough myopia (nearsighted, shortsighted) vision to deal with the myopic coupling correction, however with astigmatism this high you should expect enhancement surgery to "fine tune" the initial correction. I suspect the surgeon will attempt to correct all astigmatism first, let things settle, then enhance to resolve whatever astigmatism is not caught the first time and any myopia that remains. This seems to be the safest route for your situation. Not that two surgeries are safer than two, but correcting the biggest and most difficult error first, then resolving residual difficulties may be best.