From a surgical perspective, the selection criteria used to identify patients for LASIK significantly determines the final outcome of the procedure. A complete pre-LASIK evaluation along with suitable counselling is required to ensure the “right” individual with the “right” information for the “right” procedure. Prior to the evaluation,

From a surgical perspective, the selection criteria used to identify patients for LASIK significantly determines the final outcome of the procedure. A complete pre-LASIK evaluation along with suitable counselling is required to ensure the “right” individual with the “right” information for the “right” procedure. Prior to the evaluation, contact lens wear must be discontinued for a requisite period of time to allow the eyes to readjust and be ready for the procedure. If soft contact lenses are worn, they must be discontinued at least 3 days prior to the evaluation. Should hard or rigid gas permeable lenses be worn, they must be discontinued at least 14 days prior to the evaluation. Five core tests make up the backbone of a comprehensive pre-LASIK evaluation: ultrasound corneal pachymetry, manifest & cycloplegic refraction, slit lamp examination, dilated fundus examination and corneal topography. Pachymetry allows the doctor to determine if the cornea is sufficiently thick to undergo surgery.

At least 250 micrometres of untouched corneal thickness must remain after LASIK surgery. This level is required to guard against a condition known as ectasia whereby the cornea weakens and adversely affects vision. With an ultrasound pachometer, the doctor will use an ultrasonic wand to touch the eye and obtain a reading. The dilated fundus examination provides insight into the overall health of the individual LASIK candidate. The health status will affect post-surgical healing rates. The Wavefront-guided technology came about courtesy of developments in astrophysics. Wavefront analysis can be used in pre-surgical examination to investigate the way light interacts with the optical system of the eye. Wavefront maps can provide a 2-dimensional display of various eye conditions like myopia, hyperopia and astigmatism.

Corneal topography is able to provide a 3-dimensional view of the cornea. The technology arrived from military advances and can be employed by the LASIK doctor to measure and quantify the shape as well as the curvature of the corneal surface. Excessive corneal surface irregularity or a condition known as keratoconus can be detected by corneal topography. These conditions disqualify LASIK and necessitate other types of refractive surgery correction. A pupillometer can be used to measure the diameter of the pupil in the dark. This can be done using infrared light or a simple gauge that allows the LASIK doctor to determine the size of the pupils. Large pupils may predispose to the experience of post-surgery complications like haloes and double images.

The Schirmer test can be used to detect dry eyes. The LASIK doctor may apply a small piece of paper to the eye for a pre-defined period of time. Upon removal, the moisture content of the paper is measured to determine whether the eye is considered too dry such that further exacerbation is likely as a post-surgical complication. Several other tests are available to the LASIK doctor so that a more comprehensive picture of the individual candidate can be developed prior to further consultation. The aim is always to optimise LASIK outcomes in the quest for good vision. A stinging sensation may be felt after the procedure along with some discomfort, mild pain and tearing. The eye or eyes may be sensitive to light and appear bloodshot. Vision is also likely to be blurry but these symptoms are expected to improve dramatically within a few days of surgery. Taking a break for a few days before resuming normal activities is advisable to facilitate healing.

In the event of any severe pain or worsening vision, the doctor should be contacted immediately for follow-up regardless of any scheduled appointment. Consultations with the doctor should be regular for the first 4 to 6 months. The doctor’s advice needs to be strictly followed to optimise healing. Contact lens wear is to be avoided in the operated eye. The likelihood of developing an infection can be minimised by waiting for at least 2 weeks before resuming the use of topical preparations around the eye, the exception being those directed by the doctor. Avoiding activities that could wet the eye is crucial to facilitate infection-free healing. It is important to realise that vision may require up to 6 months of healing after surgery before stabilising.

Certain symptoms will persist through this period and may continue beyond despite improvement. Should further correction or enhancement be desired, eye measurements need to stabilise before any further surgery is considered. Enhancement surgery cannot be concluded on for efficacy because of a lack of rigorous testing. Despite the likelihood of a complication-free surgery, any new or worsening symptoms should be promptly reported to the doctor. This allows appropriate monitoring to be instituted and action to be taken in a timely fashion to prevent vision loss. These measures, when taken collectively, have an important role to play in defining the success of the whole procedure.

If you decide to go ahead with LASIK or any refractive surgery, you will need to undergo a pre-LASIK & Refractive Evaluation.

If you wear contact lenses, please stop wearing them before your pre-LASIK & Refractive Evaluation and switch to wearing your glasses full-time. This is to enable your cornea to assume its natural shape for more accurate measurements in preparation for surgery. Stop wearing soft or toric soft lenses 3 days before your pre-LASIK Evaluation, and hard or RGP lenses 14 days before your pre-LASIK & Refractive Evaluation.

You should tell your doctor:

  • Your past and present medical and eye conditions.
  • Any medication you are on and medication you may be allergic to.

The doctor will perform a thorough eye exam and discuss:

  • Whether you are a good candidate.
  • The risks, benefits and alternatives of the surgery.
  • What you should expect before, during and after surgery.
  • What your responsibilities will be before, during and after surgery.

You should have the opportunity to ask the doctor questions during this discussion. You may take some time to carefully consider before deciding to go through with surgery and before signing the Agreement to Treatment and Consent Form.

The day before surgery, you should stop using cream, lotions, makeup and perfumes to optimise surgery results: Your doctor may ask you to scrub your eyelashes for a period of time before surgery to get rid of residue and debris along the lashes. It is also recommended to arrange for transportation to and from the centre after surgery and for your first follow-up visit.

The surgery will take about 10 to 15 minutes for both eyes.

A numbing drop will be placed in your eye, the area around your eye will be cleaned, and an instrument called a lid speculum will be used to hold your eyelids open. A ring will be placed on your eye to create suction to the cornea. Your vision may dim while the suction ring is on and you may feel the pressure and experience some discomfort during this part of the procedure.

The doctor will create a corneal flap using the IntraLase or the microkeratome. During this process, you will experience fluctuating degrees of blurred vision. The doctor will lift the flap, fold it back on its hinge and dry the exposed tissue.

Another laser will be positioned over your eye and you will be asked to stare at a light to fix your eye at the correct position. A pre-programmed computer then removes a particular amount of cornea tissue based on the measurements taken during your pre-LASIK & Refractive Evaluation, marked by a ticking sound. It is normal to encounter a slight burning scent at this point. The corneal flap is then put back into position. A shield will be placed over your eye, which should be kept in place until the corneal flap has healed naturally. At this point, your LASIK procedure is complete.

Immediately after the procedure, you may experience some discomfort, mild pain or itch, while your eyes may tear and your vision may be hazy or blurry. Though instinctive, DO NOT rub your eye as it could dislodge the flap, requiring further treatment. You will be offered a mild pain reliever and your doctor will schedule a follow-up appointment.

It is normal to experience sensitivity to light, glare, starbursts or haloes around lights, or the whites of your eye may look red or bloodshot. These symptoms should improve considerably within the first few days after surgery. Do plan on taking a few days off from work until these symptoms subside.

Contact your doctor immediately, and not wait for your scheduled visit, if you experience severe pain, or if your vision or other symptoms get worse instead of better.

See your doctor within the first 24 to 48 hours after surgery and at regular intervals for the first 6 months. At the first post-op review, the doctor will test your vision and examine your eye.

You should wait 1 to 3 days following surgery before beginning any non-contact sports, depending on the amount of activity required, how you feel, and the doctor’s instructions. Do not attempt strenuous contacts sports like football or boxing for at least 4 weeks after surgery.

Do not resume wearing a contact lens in the operated eye, even if your vision is blurry. To help prevent infection, you may need to wait for up to 2 weeks after surgery or until the doctor advises you otherwise before using lotions, creams, or makeup around the eye. The doctor may advise you to continue scrubbing your eyelashes for a period of time after surgery. You should also avoid swimming and using hot tubs or whirlpools for 1 to 2 months.

During the first few months after surgery, your vision may fluctuate. It may take 3 to 6 months for your vision to stabilise after surgery. It is normal to experience glare, haloes, difficulty driving at night, and other visual symptoms during the stabilization period, which should ease gradually.

If further correction or enhancement is necessary, you should wait until your eye measurements are consistent for 2 consecutive visits at least 3 months apart before undergoing your next procedure.

It is also important to note that no laser company has presented enough evidence for the U.S. Food and Drug Administration to make conclusions about the safety or effectiveness of enhancement surgery.


Incorporated in 2005, Singapore Medical Group (SMG) is a private specialist and primary healthcare provider with a network of more than 20 medical specialties. The Group is committed to its promise of providing patient centred medical care and experience to every individual. SMG has more than 27 clinics and a growing network of SMG Associates clinics all across the island.