Lasik

WHAT IS LASIK?

LASIK is an acronym for Laser In situ Keratomileusis. It simply means shaping the cornea (the outer transparent front surface of the eye) with the use of a laser. (Kerato is Greek for cornea while mileusis stands for ‘to shape’). In LASIK, an eye surgeon makes a flap in your cornea. Vision is corrected by changing the shape of the cornea so that the rays of light can bend better and fall on the retina more precisely. The retina is the screen on the back of the eye where the images are formed before they go to the brain.

CAN IT BE USEFUL TO ME? (INDICATIONS)

• Nearsightedness (Myopia): This is a condition in which you can see near-by things clearly, but your distant vision is blurry.
• Farsightedness (Hyperopia): This is a condition in which distant objects are seen very clearly, but nearby objects appear fuzzy.
• Astigmatism: A condition in which overall vision is blurred.

HOW IS IT DONE?

Before your surgery:
• Tests like Comprehensive vision analysis, Corneal topography (the surface of your cornea is mapped), Corneal thickness measurements ( Pachymetry), Pupil size measurements, wave front analysis (to study refractive aberrations) and tear film tests are required to be done to assess the state of your eyes.
• Stop wearing contact lenses for atleast two weeks before surgery. Contact lenses change the shape of your cornea and you don’t want the corneal measurements to be inaccurate.
• Don’t use eye make up one day before your surgery.
• Arrange for a friend to relative to drive you home for your vision might be blurry.

Steps of LASIK:

1. First your eye is numbed with eye drop anaesthesia. You will remain awake throughout the procedure. An instrument called as eyelid speculum is placed to keep the eyelids open.
2. A small suction ring is placed around the cornea. This serves as a platform for the Microkeratome or the corneal blade.
3. The Microkeratome separates the cornea’s surface layers.
   
4. The corneal flap thus created is folded back.
5. You will now be asked to look at a target light. The excimer laser is now used to reshape the corneal tissue.
6. A clicking sound is heard as each layer of tissue is vaporized from the cornea. This step takes a few minutes depending on the correction that your cornea needs.
   
7. The flap of cornea is now placed back and allowed to dry for a while. This flap heals on its own without any stitches.
8. Additional eye drops are given and the eye is shielded for protection.

WHAT ARE THE COMPLICATIONS OF THE SURGERY?

• Under or Over correction or Astigmatism
• Vision Disturbances like halos, glares, double vision or reduced night vision.
• Dry eyes
• Flap displacement
• Infection

WHAT ARE THE CONTRA-INDICATIONS OF LASIK?

You are probably not a good candidate for LASIK if you have:

• Unstable Vision: If the pressure in your eyes is too high or your eyes are progressively getting worse or fluctuating you may be rendered ineligible for LASIK. Pregnancy and Breast feeding also cause your vision to fluctuate.
• Anatomic Concerns: Too thin corneas, extremely irregular corneal surface, Keratoconus, abnormal lid position or other anatomic abnormalities may be a contra-indication for LASIK.
• Immuno deficiency states like HIV, consuming immunosuppressive drugs or have autoimmune disorders like rheumatoid arthritis. All these increase the chances of complications and incomplete healing.
• Active participation in contact sports: Sports like boxing or martial arts where the chances of you taking blows to your eyes are high do not go well with LASIK.
• Persistent Dry Eyes: LASIK may aggravate your symptoms especially in ladies above 50.
• Severe nearsightedness: The possible benefits may be under weighed by the risks.
• Large Pupils: Glares, Halos, Star bursts and Ghost images are more likely to occur if your pupils tend to widen more in dim lights. This is not an absolute contraindication.
• A history of herpetic keratitis (inflammation of cornea due infection with herpes virus) is a relative contra-indication.