Custom Lasik

by **Majo** » Sat Aug 30, 2008 6:47 pm

Hello,

I dont know if this is the right place to post this as it is a mixture of "I had" with "Im thinking on having it..."

Anyway, hopefully you will give me your opinions and will share info with me...

So, I had LASIK 7 months ago... Im sooo full of disgusting Ghosts and Starbursrt (only in dim light, nights...). According to my aberrometry, it seems I have high order aberrations (HOAs), mainly coma and spherical aberrations...

My doctor suggested having an enhancement with Custom Lasik... (to correct my HOAs...)

So, my main question now is:

Does Custom Lasik really can correct HOAs ???

Thanks !!!

by **LasikExpert** » Sun Aug 31, 2008 7:21 pm

No medical device is approved to correct "Higher Order Aberrations (HOA)". HOAs are a method of measuring aberrations of optics. HOAs are a symptom, not a cause.

The cause of your particular night vision problem is undoubtedly undercorrection at the outer edge of your corneas. Read about Lasik and night vision for details.

IF the size of the optical ablation zone of the laser is able to be larger than your current optical ablation zone, then the cause of your night vision problem may be improved. Many have used this technology to improve night vision problems.

You should also discuss with your doctor if the use of Alphagan P eye drops would be appropriate.

by **Majo** » Mon Sep 01, 2008 5:13 am

LasikExpert wrote:No medical device is approved to correct "Higher Order Aberrations (HOA)". HOAs are a method of measuring aberrations of optics. HOAs are a symptom, not a cause.

What do you mean with HOAs being a symptom ??? Which is the cause then ??

Im so confused now...

Thanks

by **LasikExpert** » Mon Sep 01, 2008 6:28 am

HOAs are a measuring device. Like a yardstick. Yardsticks do not cause a mile long road, but they can measure one. It is exactly the same with HOAs. Coma is a yardstick to measure how one side of your optics is different than the other. The measuring device does not cause what it is measuring.

Spherical aberration is when the outside of your optics are different than the center. Your night vision problems are because you are more nearsighted at the outside of your optics than the center. Like a doughnut. When you pupils dilate, light passing through the undercorrected outer doughnut mixes with light from the fully corrected center and causes blur presenting as starbursts and halos.

You are undoubtedly more nearsighted at the outside of your optics than the center because the laser only treated the center and did not treat the outer area. Excimer lasers are limited to about 6.0mm of central correction. You pupils likely dilate more than 6.0mm.

Coma presents when one side of your optics is different than the other. Coma may occur if there is an incorrect alignment of the proposed laser treatment and the actual laser treatment.

Take two clear glass plates and put them one on top of the other. Ideally, the bottom would be blue (proposed treatment) and the top plate yellow (actual treatment). Aigned on top of each other, the combination of the blue and the yellow plates will appear green (full treatment).

Now move the top plate to the left a couple of inches. On the left side you will have a cresent of yellow - top plate only. In the center you have an ellipse of green - both plates. On the right you have blue - bottom plate only. That (way oversimplified) is coma.

I hope that helps.

by **Majo** » Mon Sep 01, 2008 6:43 am

Oh ! thanks !!! that definetely helped me understanding my problem !

I have now one more question....

If my pupils dilate more than 6 mm, NOTHING can help me with my night vision ???

by **LasikExpert** » Mon Sep 01, 2008 6:48 am

Lasers in conventional ablation mode can expand up to 11mm and Alphagan P can reduce the size of you pupils. Rigid gas permeable (RGP)contact lenses can reshape the corneal surface and reduce spherical aberration. Glasses may fully correct the outer doughnut of your spherical aberration and although overcorrect the center, provide good vision.

There are many options.

by **Majo** » Mon Sep 01, 2008 6:53 am

Oh ok !!!

My pupils dilate up to 7mm.... so, treating some more zone could help, am I right ? :lol:

by **LasikExpert** » Mon Sep 01, 2008 7:35 am

Treating a larger area would very likely help the spherical aberration. Coma is often better treated with wavefront-guided. This is where a knowledgeable surgeon is so important...to determine what is best.

by **Majo** » Mon Sep 01, 2008 7:41 am

LasikExpert wrote:Treating a larger area would very likely help the spherical aberration. Coma is often better treated with wavefront-guided. This is where a knowledgeable surgeon is so important...to determine what is best.

Oh !!! all right ! thank you sooooooo much for that ! :D I will ask my doctor on tuesday and if not, running with another one 8) hehe

Thanks

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