Lasik or PRK

[bunny]

Hi all,

I'm new to the board. Recently I've been considering refractive surgery. I went 2 consultations last week.

During the first consultation, they didn't really do many test. At the end of it, the surgeon only said I'm a candidate.

On the second consulation, I spend a bit more time at the doctor's office and they perform many more test than the first. The result of the consulation was, I am a candidate for Lasik because I have just enough cornea thickness to qualify. They draw the line of cornea thickness at 300 after the surgery and they said I will have 308 left if I do lasik with bladeless method. They then also said there's another option call PRK where it will preserve more of my corneal tissue so I will end up with about 100 microns more or 408.

I did some reading about PRK and it gave me the feeling that recovery will be long and unpredictable. Of course I also read all the flap complications related to Lasik. I do have to say, I'm leaning a bit more torwards lasik due to faster recovery now.

What I wanted to know is, that 308 cornea thickness that I'll be having after the surgery, is it really going to be safe? what's the thickness for most people after Lasik? Will the flap dislodge more easily than, say, 320?? Just wanted to put that 308 number into context. Will I be more prone to complications and side affect or eye disease in the future w/ 308 corneal tissue?

I also asked the dr how exact that 308 prediction will be. She said since it's laser, it should be pretty accurate, with maybe just a few micron off. Is that true?

Any information or opinion to help me understand this would be greatly appreciated!!!

Bunny

[LasikExpert]

What I wanted to know is, that 308 cornea thickness that I'll be having after the surgery, is it really going to be safe?

About 60 years of study has determined that so long as 250 microns remain untouched, a healthy cornea will remain stable. There are outliers where people with more than 250 microns beacame unstable and people with less that 250 were fine, but those are the rare exceptions. More untouched corneal tissue is always better.

what's the thickness for most people after Lasik?

This varies greatly. The larger the refractive error to correct, the more tissue that is removed. The natural thickness of the cornea varies from person to person. The depth of the Lasik flap incision varies.

Will the flap dislodge more easily than, say, 320??

I know of no study that indicates flap adhearance is affected by the amount of remaining corneal tissue so long as the 250 micron minimum is maintained.

Will I be more prone to complications and side affect or eye disease in the future w/ 308 corneal tissue?

Theoretically no, but there is nothing that screws up a perfectly good theory faster than reality. The two issues of concern with a thinner cornea are ectasia and complications from keratoconus.

Keratoconus is a disease of the cornea that causes weakening. If there is a family history of keratoconus and you are age 40 or younger, then you would have an elevated risk of developing this disease. Scans of the front and back of the cornea can indicate if you have early stages of keratoconus. Long-term use of hard contact lenses can sometimes mask keratoconus development. Being out of hard lenses for a few weeks before being tested for everything related to refractive surgery is required.

Ectasia is a forward vaulting of the cornea due to weakness caused by too much tissue removal. The 250 micron minimum rule is to prevent ectasia.

I also asked the dr how exact that 308 prediction will be. She said since it's laser, it should be pretty accurate, with maybe just a few micron off. Is that true?

Generally yes, but not always. The laser is affected by many factors. The relative humidity on that day can make the laser stronger (low humidity) or weaker (high humidity). The barometric pressure can affect the laser (high weaker, low stronger). If your corneas are not well hydrated or become unusually dry during surgery more tissue than normal may be removed. The microkeratome that makes the Lasik flap can commonly be off by 10-20 microns. Good surgeons take all of these factors into consideration when creating their final treatment plan, but a micron is rather small. A human hair is about 60 microns wide. A single corneal cell is about 5 microns across.

I have a personal preference for PRK or its cousins LASEK and Epi-Lasik over Lasik. Although the probability of a Lasik flap complication is relatively small, no Lasik flap means no possibility of a Lasik flap complication. No possibility of a problem is almost always better than a low probability. Yes, vision recovery with PRK is longer than Lasik, but that inconvenience may be worth the extra margin of safety. I like to tell people that for the first three weeks they will wish they had Lasik, and for every day thereafter they will be glad they had PRK.

[bunny]

Hi LasikExpert,

Thanks for all the info. Sorry for the late reply as I was out of the country. I find your info extremely useful.

I'm leaning more toward PRK since many of the forum posting I've read kind of suggest that PRK is safer (in terms of side affects) than Lasik. Although I am very concern about the uncertainty of the recovery. I've heard good cases that people have pretty good vision after a week, but also heard bad cases where people won't be able to see much for months. I really am not sure what to expect. I just hope that I could function and go to work after a week. Is that the case for most people?

I am planning to go back to the surgery and ask more questions about PRK. What are some of the questions you think I should be asking at this point?

Thanks again for all your help!!

[LasikExpert]

What are some of the questions you think I should be asking at this point?

Check our important questions to ask about Lasik or PRK.