Lasik complications - how big is the risk?

Lasik candidates need to know that complications and side effects are a possibility.  The Lasik procedure is surgery, and there are never 100% guarantees in any form of surgery.   However, although people know things can go wrong, public confidence in Lasik surgery is high.

American surgeons first started using the procedure in 1990, and since then millions of Americans have been treated. The percentage of Lasik complications has been falling for years.

Equipment and procedures have improved steadily, but the most important factor seems to be practice. Experienced surgeons report Lasik complication rates of less than 1%, while rates as high as 5% were reported when Lasik was first used.

Flap problems

Most Lasik problems occur around the creation of the flap. In a Lasik procedure, a blade (called a microkeratome) or a laser is used to cut a flap in the front of the eye, the cornea.

The surgeon lifts the flap, uses a laser to reshape the eye, and the flap is replaced.

Problems arise when the flap is cut too thin, or too thick.

Sometimes the flap fails to re-adhere to the eye when it is put back.

Sometimes the Lasik flap starts to wrinkle when it is put back on the surface of the eye.

Almost all these problems can be fixed by re-treating the eye (a procedure called an enhancement), usually about nine months after the first operation.   By this time the eye will have healed and stabilized.

The American Journal of Opththalmology says that flap problems happen in between .3% and 5.7% of Lasik procedures - quite a wide range. A 2004 report said that flap problems had fallen to only 0.1 to 0.2%.

Choose experienced surgeons

Because inexperience is such a big factor in Lasik complications, it probably makes sense to choose an experienced surgeon to move the odds in your favour.  

A possible side effect is inflammation where the flap makes contact with the eye.   Another is called epithelial ingrowth, in which cells lining the surface of the eye move underneath a problem flap and start growing.

As this happens after the actual Lasik procedure, further treatment comes under the heading of post-operative care.

But the odds, in general, are good. Very few patients suffer lasting damage that seriously threatens their vision, and most Lasik complications are cleared up via a further enhancement.