LASIK

LASIK or laser-assisted in situ keratomileusis is performed to correct vision defects and decreases the need for contact lenses or prescription glasses with the use of lasers.

Normally, when the light passes through the cornea (the transparent covering of your eye in the front) and lens (located just behind the pupil, focuses light towards the retina) it is bent (refracted) and then focused on the retina (the tissue lining the inside of the back of the eye). The retina has various types of cells (rods and cones) that perceive the light and colours and send signals to the brain where they are interpreted.

If you have a defect in shape of your cornea, lens or eyeball, the light will not be focused on your retina, and your vision will be blurred or out of focus.

Your ophthalmologist (eye doctor) may recommend this surgery if you have the following refractive errors:

• Myopia (nearsightedness)
• Hyperopia (farsightedness)
• Astigmatism (blurred vision)

The commonly observed symptoms of refractive errors are:

• Blurred vision
• Cloudy vision
• Double vision
• Headache
• Squinting
• A halo or glare around bright lights
• Straining of eyes
• Difficulty in focusing when working on a computer or reading

Some people may not show any symptoms.

You may be eligible for the surgery if you: 

• Are 18 years of age or older
• Have an eye problem that can be treated by this surgery
• Your eye prescription has not changed for a year
• Have a thick cornea, and your overall eye health is good
• Have realistic expectations from the procedure

LASIK cannot be performed if you have:

• Advanced glaucoma
• Uncontrolled diabetes
• Severely dry eyes
• Vision affected by cataract
• Extreme levels of hyperopia, myopia or astigmatism
• A history of eye infections
• A changing or unstable refractive error
• Very thin or cone-shaped corneas
• Are nursing a baby or pregnant

The following preparations are needed before the surgery:

• Your ophthalmologist will conduct an eye exam to make sure that you are a good candidate for the surgery. The screening may include:
  • Checking the overall health of your eyes
  • Measuring the size of the pupil and thickness of your cornea
  • Measuring the refractive error of your eyes
  • Checking the amount and quality of your tears
• During the screening tests, you may be asked to:
  • Discontinue wearing your contact lens. Rigid gas permeable contact lenses should be discontinued at least three weeks before the screening for surgery, whereas all other types of contact lens should be discontinued three days before the screening.
  • Bring your current eyeglasses for the screening to review your prescription.
• Your doctor will check your medical history and ask you to discontinue using makeup, perfume and lotions for a few days before the surgery.
• You will need to make arrangements for a responsible adult, friend, or family member to take you back home after the surgery.
• If you agree to the procedure, the medical staff will ask you to sign an approval form to grant your permission for the procedure.

The following preparations will be required on the day of the surgery:

• You may be asked to take your usual prescribed medicines.
• Eat a light meal before visiting the hospital for surgery.
• Do not wear any accessories in your hair as it may affect the position of your head during the surgery.
• If you are unwell on the scheduled day of the surgery, inform the ophthalmologist. The surgery may be postponed in such a case.

LASIK is performed either in your ophthalmologist’s office or at an outpatient surgery centre. You will be given anaesthesia via eye drops. This will numb your eye for the procedure. A computerised laser will be used to reshape the cornea.

The surgery involves the following steps:

• After your eye is moistened and numbed with eye drops, the surgeon will place a suction ring over your eye to keep it from moving and to maintain your cornea in the proper position. The ring will make you feel some pressure on the operated eye, similar to the feeling of a finger being pressed firmly on the eyelid.
• The ophthalmologist will use either a laser or a blade-like device to make a flap as thin as paper in your corneal tissue. He/she will elevate this flap and fold it back to expose the stroma (mid part of cornea).
• The ophthalmologist will ask you to stare at a source of light to prevent your eyes from moving. 
• Then, he/she will reshape your cornea with a laser, an instrument pre-programmed with the measurement of your eye. You may hear a clicking sound during the process.
• After the cornea is reshaped, the surgeon will fold back the flap back to its original position, and smoothen its edges. The flap will then be left in place to heal.
• Finally, the surgeon will place a perforated metal or clear plastic shield above your eyes to guard the flap. Make sure to keep it in place for a few days.

The surgery involves no stitches and takes around 15 minutes for each eye. At times, both the eyes are operated in the same session. At other times, your surgeon may prefer to wait for a few days or weeks to see the results before operating on the other eye. You will be able to go home on the same day.

Once you reach home, you will need to take the following care:

• Your eyes may have an itchy or burning sensation for a few hours. Your doctor will prescribe special eye drops to you to help them heal. Use the drops as advised.
• You may experience blurry vision on the day of the surgery and the next day, but it will improve eventually.
• You will need to wear a shield over your eyes while sleeping for two weeks to help protect them as they heal.
• Make sure to keep blinking your eyes frequently.
• Although healing is quick, you will need to rest for a few days before resuming work.
• Do not play sports for the first three days after surgery and impact sports for four weeks following the surgery.
• Do not rub your eyes.
• Do not splash water on your face and eyes or take a head bath for about 14 days.
• Do not drive for a few days after the surgery. or until your surgeon allows you to.
• Avoid eye makeup for a month after the procedure.

When to see the doctor?

Visit or call your doctor if you notice any of the following symptoms after the surgery:

• Redness, discomfort or pain in the eye
• Any vision-related symptom that was absent before the surgery
• Fever
• Reduced vision
• Symptoms that worsen and do not subside with treatment
• Unusual or aggravated symptoms

Some of the risks of LASIK are as follows:

• Dry eyes
• Vision changes
• Discomfort or pain in the eye
• Blurry or hazy vision 
• Eye glare
• Irritation in eyes
• Experiencing halos around light
• Inflammation in eyes
• Appearance of small red or pink patches on the white part of the eye
• Increased sensitivity of eyes to light

Although some of the risks mentioned above are commonly experienced after a LASIK surgery, these may disappear in due course of time. Some of the rare risks include:

• Vision worsens instead of improving after the surgery
• Blindness
• Eye infection
• Under- or over-corrected vision

Your follow-up visit will be scheduled the very next day of the LASIK surgery where your doctor will examine your eye and vision.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.