Close, hard look at cutting-edge eye surgery

Laser eye surgery is proving to be a life-enhancing solution for people with impaired vision who find it uncomfortable to wear glasses or contact lenses.

But the technique is not without its risks. It is important to completely understand the pros and cons of the surgery - the requirements before surgery, what will happen during surgery and what to expect after the treatment.

LASIK (Laser-Assisted In Situ Keratomileusis) is a procedure that permanently changes the shape of the cornea through the use of a laser, effectively reducing a person's dependence on glasses or contact lenses.

During surgery, an instrument called a microkeratome is used to cut a flap in the cornea. A hinge is left at one end of the flap, which is then lifted so the laser can work on the corneal bed. The cap is repositioned after the treatment.

Vision returns fast after LASIK surgery, which causes patients little discomfort. By the next day, patients typically feel and see well enough to work, though this may vary from individual to individual. A patient's vision will continue to improve and stabilise over the next one to three weeks.

Before surgery, an eye assessment would be performed to determine, among other things, the extent of refractive error, the presence of any eye diseases and general medical history, said Alfred Leung, consultant ophthalmologist of the Eye Centre at Hong Kong Baptist Hospital.

The assessment will determine whether the patient is fit to undergo LASIK treatment.

'Generally speaking, good candidates for LASIK surgery are typically at least 18 years of age and have nearsightedness of between one and eight dioptres (100 to 800 degrees) and astigmatism less than 1.5 dioptres. They usually achieve an excellent result,' Dr Leung said.

'However, candidates who have nearsightedness of between nine and 12 dioptres may have a higher risk of overcorrection or undercorrection in the process. Consideration should be given to potential post-surgery trouble with night vision such as glare or halos,' he added.

Any surgery carries risks, however remote they may be.

Wound infection was one of the risks in LASIK surgery and about one in 10,000 patients might experience this potentially serious complication, Dr Leung said.

'Also, about one out of 300 cornea flaps created by the microkeratome is unsatisfactory and may lead to the suspension of LASIK procedure,' he said.

To minimise some potential post-surgery problems, Wavefront-guided LASIK technology has been introduced to reduce night glare and halos. Wavefront-guided LASIK is a new technology providing an advanced method for measuring optical distortions in the eye. It allows physicians to customise the LASIK procedure according to each individual's needs.

Another new technique, IntraLase, also tries to allow for correction of higher refractive errors, especially for people with thin corneas. The technique meant it was possible to make precise, shallow flaps, he said.

This technology uses a separate laser device rather than the microkeratome used to create a corneal flap during LASIK surgery, thus increasing its safety.

John Chua, a specialist in Ophthalmology with Quality HealthCare LASIK Centre, said if you were worried about your reading vision and you were over the age of 40, you could opt for monovision.

'This is to correct one eye for distant vision and leave the other undercorrected for near vision,' he said.

'A detailed interview with your ophthalmologist is important to assess your suitability, the usual activities you enjoy and your expectations.'

The surgery took about 15 minutes and patients usually experienced no pain during treatment as the eyes were numbed by a local anaesthetic, Dr Chua said.

'Being nervous during surgery is very normal. As long as one can co-operate and follow the doctor's instructions, the results will not be affected as safety measures such as a fast eye-tracking system is used,' he said.

Health Aesthetics, an independent medical retreat founded and run by doctors, offers LASIK treatment and a trip to Thailand all in one package. Health Aesthetics Hong Kong office director Ethan Pang said: 'The entire trip can be as short as three days and two nights although four days three nights is recommended. Our clients and/or their accompanying partners often take this chance to undergo other treatments such as cosmetic skin treatments, dental and even cosmetic surgery. Some clients incorporate further rejuvenation and relaxation activities in Thailand.'

With its base in Bangkok, the Hong Kong office takes care of the pre-LASIK assessment and arranges the post-LASIK follow-up treatment with its partner optometrist.

'Once the candidate is found suitable for the LASIK treatment, arrangements will be made for a priority appointment with our surgeon,' Mr Pang said.

As with any surgical procedure, there are potential risks involved in LASIK surgery. People who are interested in learning more about LASIK should seek the advice of an ophthalmologist and undergo a medical check-up.

Dr Leung also recommends the following website: www.aao.org