My aunt had Lasik 4 years ago, and my boyfriend had PRK in June. I'll go through the risks/benefits below.
Infiniti2000 said:
1. LASIK - aka Flap n' Zap. Whether the flap is made from a microkeratome (the blade) or another (very expensive) laser doesn't make a whole lot of difference. This produces the fastest healing time but it makes your cornea significantly weaker and the flap never fully heals. It also preserves the Bowman's membrane, whatever that does (note: no one really and truly knows for sure, but the guess is that it's a 'germ' barrier of some sort). I have seen surgeries where a surgeon performed an enhancement two years later, peeling the flap back like a scab. I can upload video if anyone wants. (Okay, no, I won't. Too much trouble.)
LASIK is much less painful than PRK, and the recovery time is theoretically less. However, if you are physically active, LASIK is not right for you. (Hence the reason the military doesn't use it) The thing is, if you are hit hard enough (not necessarily in the eye, just enough to send physical shock through your body) the flaps from the surgery can detach, and then your eyeballs are (painfully) flapping all over the place. I hear it really sucks.
My aunt had LASIK 4 years ago (as she is not in the habit of being forcibly active) and she liked it. However, now she still needs to wear glasses for driving and reading.
2. PRK - The epithelium (and Bowman's layer) are removed. This is about 50 microns of tissue, but the epithelium grows back. The fact that it grows back and the loss of it in the first place is why this method is a lot more painful and takes longer to heal. But, the integrity loss is far less than LASIK. Also, because of the much greater healing that must occur, it is far less predictable. The removal of the epithelium can be done with alcohol or a wire brush or even the laser itself (this last one called transepithelial PRK). This is the method that is recommend by the US Armed Forces, btw, and the only one allowed for entrance into certain special forces. At least, it was a couple of years ago. I dunno if they changed that.
This procedure (at least in the Army) takes about 12 minutes. They numb your eyes and use metal implements to force them open. They then pour an alcohol solution over the epithelium to dissolve it, and then use a wire brush (that sort of resembles a miniature cheese grater) and they grate away the dissolved layer, actually forcing the layer into the correct shape. (You get to watch them do this). Then, they put giant contact lenses in to replace the epithelium until it grows back (about 7 days). You get lots of eye drops, and you'll have to put them in every hour (regular "tears" and stereoid drops to help the eye heal faster). You'll get stupid goggles to wear while you sleep so you don't accidently poke yourself in the eye, and you have to wear them in the shower too. You will need to wear sunglasses every time you go outside for about a month (recommended).
The third day after your surgery will suck beyond all belief. You will feel like there is crap behind the contact, and your eyeballs will feel like they are coming out of their sockets. You will call your doctor, swearing something is wrong. He will say this is normal, and that the 10 other people who had PRK with you have just called him to say the same thing. You will curl up in pain and sleep for most of this day. Don't worry, it goes away.
After the first week, they'll remove the contacts and you can stop using the stereoid drops. PRK might suck, but it's got a much lower rate of recurrance and a lower rate of complications. With PRK, the eye does fully heal.
I can't imagine how painful and unpleasant THAT would be....
