Many patients can have either LASIK or LASEK and want help to decide which one to have.

Essentially, the 2 operations achieve the same results and cover the same range of prescriptions (+4 to -8 approx.)

However, LASIK is a nicer surgical experience for the patient as there is quick visual recovery and no pain apart from a little grittiness.

Fairly clear vision is achieved from about 3 to 4 hours post op and both eyes can be treated on the same day even in high prescriptions. On the downside, there is more risk than any variety of surface laser (PRK. LASEK, Epiflap, Epi-LASIK) as in LASIK a flap is cut with a mechanical microkeratome or with a femtosecond laser.

Most LASIK complications are flap complications and there is the same risk in treating a small prescription such as a -1 and a large one such as -10. The cut edge of the flap is covered over by epithelium by the next day but the interface always has a potential space. It is useful to think of the analogy of a self-sealing envelope flap - you throw it in the post and it travels across the country without falling to bits. However, at the other end one can lift up the stuck flap with a letter-opener. Although we surgeons find it quite easy, in the first few months especially, to peel open a flap with a similar sort of "letter-opener" , in real life this seems to happen only infrequently. It really requires a direct oblique physical blow onto the eyeball to dislodge the flap.

However, we advise patients who indulge in physically risky situations to have surface laser rather then LASIK. Such would be rugby players, boxers, karate etc. The American army now accepts both LASIK and LASEK. Recently astronauts have been allowed to have LASIK with the flap cut with a femtosecond laser. It is not known if a femtosecond flap is more robust than one cut with a mechanical microkeratome.  A femtosecond flap with a backward cut edge might well be the strongest option and this is just coming into normal practice.

LASEK has a slower visual recovery and is also more painful. Pain is a lot less than it used to be with PRK because of the epiflap technique, silicone contact lenses post op, anaesthetic drops and better oral medication. Most patients have some pain the first few hours for days 2 and 3 usually just a little grittiness and photophobia. We give patients anaesthetic drops to use during this period. Patients will see at day 1 post op with LASIK what they will see at day 4-5 with LASEK, but at 1-2 weeks post op there is no difference in vision even with large prescriptions. In fact there is a quicker recovery of low light vision with surface laser than LASIK.

LASEK patients are back to the baseline pre-operative values by 1 month post-op, whereas with LASIK this normally takes up to 3 months and occasionally longer. You need longer off work with LASEK than LASIK as the special "bandage" contact lenses come out at 3 to 4 days post op. If I operate on a Friday, then the contact lenses come out on Monday and the patients are back to work on Tuesday or Wednesday with a small prescription. The bigger the initial prescription, the slower the visual recovery. It is reasonable to do a bilateral same day LASEK up to about -5. For higher prescriptions than this, I usually do one eye at a time unless the patient has got a week free. One is not blind during this time but may not be up to driving standard.

LASEK has less risk that LASIK because there is no flap cut. However, complications are rare with either operation. LASIK flap complications are around 1 in 1000. The major risk with LASEK used to be "haze", but we now use prophylactic Mitomycin-C during surgery, which has almost completely eliminated this problem. LASIK seems to be more prone to causing dry eye problems than LASEK.
For longsight (hyperopia), it is normally better to have LASIK.