I just had 3 month follow up today, and very upset. As my cornea thinkness is now 398mm. The thick part is about 430mm. I am so worry about the estasia.The doctor said I am still fine but I sitll quite concern about this as it is thinner than I thought. As I read some articles and it says if the cornea thinkness is below than 250mm, the chance of getting ectasia is 1/250. By the way if estasia happened, is there any treatment?

The total thickness of your cornea is not the issue regarding ectasia. The issue is the thickness of the untouched portion of your cornea.

In the five-plus decades of lamellar corneal surgery, it has been well established that 250 microns of cornea must remain untouched for a healthy cornea to remain stable and not bulge forward as in ectasia. More is always better, but 250 is normally enough.

If the thinnest point of your total cornea is 398 microns and you need 250 microns for stability, then that leaves 148 microns to accommodate the LASIK flap. It is very, very likely that your LASIK flap is 148 microns thick, or less.

If the flap was created with a mechanical microkeratome, the central portion of the flap is thinner automatically. If the flap was created with a laser microkeratome (IntraLASIK), the laser can make a flap that is as little as 100 microns thick.

If you did not have LASIK and had a surface ablation technique like PRK or its cousins LASEK and Epi-LASIK, then your untouched corneal thickness would be 398 microns.

Ask your doctor for the actual thickness of the untouched portion of your cornea. The doctor would know this by either calculating the total preoperative thickness minus the projected flap thickness, or the doctor may have taken an ultrasonic reading of the residual corneal thickness during the operation.

If ectasia occurs, the consequence is usually normal myopia. Myopia can be corrected with glasses and contacts. If the ectasia is severe, surgical correction with Intacs may be an option.

Glenn Hagele
http://www.USAEyes.org

I am not a doctor.

Thank you very much for your reply and I just read the article about the cornea heal which says after two years the flap can contribute some degree of protection the the residual cornea. BTW, to what degree? 50% or even more. And does that mean after two years, there is lee likely to develop cornea estasia?

Thanks!

Glenn,
You stated that Intralase creates a thinner flap than blade type. Would it stand to reason then that the thinner flap would be easier to get flap wrinkles? It would be my first thought.