LASIK is short for “laser-assisted in-situ keratomileusis”. It is a procedure used to correct myopia, hypermetropia and astigmatism.
What is the aim of LASIK surgery ?
WHAT ARE THE CRITERIA FOR A PERSON TO UNDERGO LASIK ?
The main aim of LASIK surgery is to reduce the person’s dependence on spectacles or contact lenses for various reasons such as
- convenience for activities such as sports, frequent travelling
- contact lens – related problems
HOW IS LASIK CARRIED OUT ?
In general, the candidate should :
- Be at least 18 years of age
- Have a stable prescription for spectacles or contact lens for two years prior to surgery
- Have an adequate corneal thickness
- Not have any associated eye conditions such as glaucoma, cataract, retinal detachment or keratoconus
- Not have other conditions which may predispose to corneal abnormalities such collagen vascular diseases or pregnancy
A thorough history and eye examination will enable the surgeon and staff to assess the suitability and manage the expectations of the patient. This will ensure a more successful outcome of surgery.
Prior to the initial consultation, the patient should refrain from wearing contact lenses for one week (soft lenses) and two weeks (hard lenses) to prevent corneal warpage from affecting the eye measurements that will be done.
WHAT RANGE OF REFRACTIVE ERRORS CAN BE TREATED WITH LASIK ?
There are two main steps in LASIK:
creation of a ‘flap’ in the corneal surface using a microkeratome (a device with a very fast oscillating blade) to ‘open up’ the cornea
use of the Excimer laser to reshape the underlying corneal tissue according to the type of refractive error present in the eye, the majority of which is myopia.
For myopia, the centre of the cornea is flattened to to reduce its refractive power.
For hypermetropia, the cornea is steepened to increase its refractive power.
For astigmatism, the laser smoothens out the irregular shape of the cornea to even out its refractive power.
After the laser treatment, the flap is unfolded and smoothed over the cornea to which it will adhere without the need for stitches.
The whole procedure takes about 10 minutes to perform and is done on an outpatient basis. It is painless as anesthetic eyedrops are used, although there may be some tearing and discomfort in the first 24 hours after surgery. These will gradually resolve by the second or third day.
It is also the current practice to operate on both eyes consecutively on the same day.
WHAT IS THE SUCCESS RATE OF THE SURGERY ?
In general, myopia up to -15.00diopters, hyperopia from +1.00 to +5.00 dipoters and astigmatism from -0.5.00 to -4.00 diopters can be treated with LASIK, with the actual amount dependent on the characteristics of the individual’s eyes.
HOW SOON CAN THE VISION IMPROVE AFTER SURGERY ?
In general, about 97% of patients with mild to moderate myopia who undergo LASIK are able to attain a vision of 6/12 or better without spectacles or contact lenses and of these, about 70% will have perfect vision (6/6) unaided.
It must be noted that these percentages will be lower for those with a higher degree of myopia and reading glasses will still be required for near work when presbyopia sets in later on in age.
WHAT ARE THE SIDE-EFFECTS AFTER LASIK SURGERY ? IS POORER VISION OR EVEN BLINDNESS A POSSIBILITY ?
Most patients will experience good vision within 24 hours after surgery, with gradual improvement over the next few days.
HOW SOON CAN NORMAL ACTIVITIES BE RESUMED AFTER LASIK ?
The common side-effects after LASIK are dry eyes, light sensitivity , glares and halos during the first two weeks, with most of them subsiding over time.
Blindness is very rare but can occur if there is a serious infection or scarring.
However, antibiotic eyedrops are routinely prescribed to prevent infection and in the hands of an experienced surgeon, there is very minimal risk of the vision ending up worse than before surgery.
WHAT IF THE VISION IS NOT FULLY CORRECTED AFTER THE PROCEDURE ?
It is advisable to rest for 1 to 2 days after LASIK. Avoid crowded and dusty environments to lessen the risk of eye infection.
Swimming and water sports are to be avoided for two weeks and contact sports for …. Months after surgery.
Air travel is safe after LASIK.
HOW OFTEN WILL THE REVIEWS WITH THE SURGEON BE AFTER LASIK ?
If there is any under- or over-correction of the vision after the initial procedure, enhancement surgery can be performed but only after 3 months so as to allow the refraction to stabilize.
Enhancement surgery is done by using a special instrument to lift up the corneal flap, without cutting, and then proceeding with laser correction.
The schedule of reviews after LASIK is:
- one day
- one week
- one month
- three months
- six months
In case of any doubts or symptoms outside of this schedule, it is advisable to speak to the surgeon or nursing staff for further advice.