Thin cornea and risk of keratoconus

Hi Doctor I had LASIK surgery 4 years ago in China and current thickness of cornea stroma is 270 um. My vision of both eyes are 20/20 and no astigmatism. Before the surgery my cornea thickness is more than 400 and less than 500 i remember (i have high myopia).

1. i was told by one opthalmologist that the safety level is 250 um. if cornea is thicker than that it could be safe to maintain the normal curve and shape of cornea, is that correct?

2. based on current LASIK histroy and data if i didn't have keratoconus before surgery and don't have it either after 4 years of surgery, does that mean my risk for developing keratoconus is pretty low?

Thank u very much.

[John C Hagan III, MD, FACS, FAAO]

1. Since you have not had changes in the past 4 years you likely not have further changes.
2. LASIK doesn't cause keratoconus. If too much tissue is removed and the corneal becomes unstable it's called corneal ectasia. K-conus is a contra-indication for doing LASIK.

JCH III MD