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LASIK: a safe and effective method of laser eye surgery

Sarah Brewer
Medical Journalist and Clinical Assistant in Genito-Urinary Medicine
Queen Elizabeth Hospital
King's Lynn

Laser eye treatment has advanced considerably over the last few years with the introduction of LASIK (laser in-situ keratomileusis). Unlike older methods, LASIK produces virtually no postoperative discomfort and, as well as correcting short sight, can correct long sight and astigmatism too. A full eye examination is necessary to assess patient suitability for the procedure, which should never be carried out on the same day as the initial consultation - it is important that patients are given time to consider their decision about whether or not to go ahead.

How is it carried out?
During LASIK treatment, local anaesthetic drops are used to numb the front of the eye and patients are offered light sedation to help them relax.

The eyelids are gently held apart by a small eye-guard, and a suction ring is centred around the cornea to hold the eye still and raise intraocular pressure. An instrument called a microkeratome is then used to lift a thin flap of tissue from the corneal surface, which is then folded back out of the way and the suction ring removed. The patient is asked to look at a blinking target light and an ultraviolet laser is used to accurately reshape the middle layer of the cornea according to their prescription. Laser reshaping takes from a few seconds to less than two minutes, and the flap of corneal tissue is then replaced. It quickly readheres to the front of the eye through natural processes, without the need for stitches.

Antibiotic drops are inserted and a temporary, plain "bandage" contact lens may be fitted for 24 hours. Both eyes can be treated together, and improvement in unaided vision is usually immediate. Most people undergoing the procedure report either no or very little discomfort.

Immediately afterwards patients are unable to drive, so someone must be available to take them home following surgery. For the first day they should simply relax and keep both eyes closed as much as possible to rest as healing progresses. Patients are advised to wear a plastic eyeshield at night for the following month to prevent rubbing their eyes during sleep. It is also sensible to wear plain glasses initially when outdoors, to prevent grit and suchlike getting in the eye. Follow-up checks are carried out the day after the operation, and during the following few weeks as necessary. Drops are usually prescribed containing antibiotics/cortico-steroids and artificial tears.

When treating short sight, results vary depending on the type of laser used. The best results are currently achieved by the Bausch & Lomb Technolas(TM), with 84.8% of patients achieving 6/6 uncorrected vision or better when tested six months after the operation, and 99.7% meeting or exceeding the minimum standard for driving (6/12).

Possible side-effects
Numerous clinical trials have shown that LASIK is safe and effective when performed by experienced surgeons. There are no known long-term side-effects or complications. The risk of complications during the procedure itself (eg, irregular flap or flap cut through) are low at 1-2%, and usually just require postponement of the procedure to a later date.

People may initially experience fluctuations in vision from morning to evening, and will see halos around lights at night due to normal postoperative swelling.

The risk of side-effects such as a "halo" or glare around bright lights is low with the new-generation lasers used, but around 10% of patients experience temporary decreased night vision.

These early side-effects usually resolve over 4-6 weeks as healing progresses. Dry eyes are another common side-effect of laser surgery. This usually disappears within a few weeks to months but is occasionally persistent.

Risk of complications at three-month follow-up varies from 2.6% to 6% in various studies - corneal oedema (0.6%), corneal scarring (0.1%), persistent epithelial defect (0.5%), significant glare (0.2%), persistent discomfort (0.5%), interface epithelium (0.6%), cap thinning (0.1%), and interface debris (3.2% although this usually causes no visual problems). The risk of complications seems to be significantly lower when the surgeon is experienced in the procedure. The cost of the procedure is around £1,750 for both eyes.



For further information contact LASIK
T:Freephone 0808 144 2020