June 4, 2009
All about Lasik
Ever since the Lasik procedure emerged two decades ago, millions of myopia sufferers have had their blurred vision reversed.
Lasik - laser in-situ keratomileusis - is a painless 15-minute procedure that frees one of the need for glasses or contact lenses permanently.
It involves creating a flap in the cornea either with a blade or laser, and subsequent laser treatment to reshape the cornea, hence sharpening one's vision.
The cornea is the transparent outer layer that covers the front of the eye.
Associate Professor Leonard Ang, the opthalmologist and medical director of Premium Lasik Surgery Clinic, answers some common questions about the popular procedure that was performed on about 32,000 people here last year.
Why go for Lasik?
It is a proven, safe and effective way of correcting refractive errors - myopia and astigmatism.
The key benefit is that of convenience. You do not have to spend time cleaning contact lenses or stay away from certain sports.
You also save money in the long run as you no longer have to regularly change your spectacles or buy contact lenses and solutions.
More importantly, you no longer have problems associated with improper contact lens care. For instance, corneal infections commonly occur with prolonged lens wear and inadequate cleaning.
Who is suitable?
You must be at least 18 years old, with no increase in refractive error (when light does not focus perfectly onto the retina) for the past year. You are never too old for Lasik, so long as an opthalmologist assesses you to be suitable.
Lasik can treat refractive errors of up to 1,500 degrees.
However, it is not advisable for people with an existing eye disease, like glaucoma and cataracts. It may not suit people with irregularly-shaped or overly thin corneas as well.
But people cured of their eye diseases, like cataracts, may be found suitable.
If Lasik is not an option, are there others?
There are two alternatives: epiLasik and contact lens implants. The former is like Lasik but without cutting of the cornea. Only the laser treatment is done. The problem is that more healing is involved.
If you have high myopia, there may be more scarring which can cause blurred vision again. Hence, epiLasik is recommended for myopia of under 700 degrees.
Implantable contact lens are like permanent contact lenses. Inserted in front of the natural lens, they are suitable for those with thin corneas and whose myopia is very high.
Can myopia ever return after eyesight has been corrected by Lasik?
Myopia can either return naturally - a person's myopia may continue to increase slightly over his lifetime - or when the eyes are over- or under-corrected after the initial Lasik surgery.
Enhancement surgery can be done for both cases. This is like a 'top-up' of the laser treatment and there is no need to cut the cornea again.
This cannot be immediate - it can be done three or four months after Lasik, when your eyesight has stabilised.
On average, 3 to 7 per cent of patients may need a re-treatment to obtain perfect vision.
What are the common side effects?
Dry eyes, seeing halos and starbursts at night. However, these symptoms are temporary and will fade after a few weeks.
What are the possible risks?
During surgery, there may be complications involving the corneal flap. In this case, the surgery is likely to be postponed for a few months.
Severe complications, such as infections, are extremely rare - averaging one in 5,000. If detected early enough, the problem can be fixed and good vision can still be attained.
What steps are involved?
You will first go through a three-hour evaluation to assess your suitability for the procedure.
The procedure is an outpatient one, you do not have to be hospitalised.
During surgery, a series of eye drops - antibiotics and drops to numb the eye - will be applied. You are awake throughout. Up to seven minutes is needed to treat each eye.
After the operation, the patient has to wear protective eye glasses. Lubricating eye drops and topical medication are also given.
Three follow-up appointments are required - the following day, one to two weeks later, and one to three months after the last appointment.
What happens the day after the procedure?
You can expect your eyesight to improve by 80 to 90 per cent. There is no need for you to stay at home to rest and you can go back to work.
What should I avoid doing?
Avoid touching the eye and definitely no vigorous rubbing. The corneal flap is still unstable in the first few days after surgery and it may get displaced. However, should that happen, the flap can be easily realigned.
Stay away from swimming and contact sports for at least a month, as it takes about two months for the cornea to heal completely.
Will there be any problems if I suffer from other eye diseases in the future?
No. Lasik does not hinder you from receiving standard treatment for other eye conditions in the future. It does not lower your chances of successful surgery, nor does it increase your risk of getting an eye disease.
How much does it typically cost?
Prices range from $1,000 to $2,500 per eye, depending on the surgeon's credentials and the technology used, as well as the centre you go to. For instance, bladeless Lasik (where laser is used to cut the cornea) costs more as the technology is more advanced. It was introduced here about eight years ago.
Poon Chian Hui