Lasik

Lasik


Procedure:

The laser technique involves working on the corneal bed, under the Bowman layer where there are no cells or nerves which can lead to scarring. With the LASIK procedure, a small 8mm diameter flap with a thickness of 130-160 microns, is cut from the surface of the cornea. This flap is not totally cut off and is still attached to the cornea with a small hinge.

After the flap is flipped to the side, the corneal stroma is ablated with the Excimer Laser after the computer has been programmed with the patient's refraction and corneal thickness. The excimer Laser removes corneal stroma at 0.25 microns per pulse (a 1/4 of a 1/100th of a millimeter). The aperture of the laser changes with every ablation and thus by removing the tissue layer by layer a perfect lens cut into the corneal stroma is achieved. The flap is then replaced on the ablated area and takes up the curvature of the new ablated cornea. In normal circumstances the corneal epithelium heals within 10-12 hours.

Am I a Candidate?

  • Before this question can be answered, one has to have a thorough evaluation. This will include a general eye examination, corneal topography (mapping), pressure check and measurement of the corneal thickness. It will also exclude any general eye disease. Only then can the surgeon tell you if you are a candidate.
  • The minimum age of 18 years provided the refraction is stable. There is no maximum age.
  • The refractive error must be in the range of treatment that the laser is capable of treating.


Contra-Indications:

  • Cataract
    It is an opacificaion of normal lens of the eye leading to light scatter and poor vision. It is one of the major causes of blindness in the world. The cataractous lens is removed with phaco-emulsification and intra-ocular lens is implanted to correct the vision.

    Cataracts are removed by the most modern techniques namely clear corneal sutureless incisions under local or topical anaesthesia. This is done on a day patient basis and restrictions of activities are minimal. This can also be combined with the international package deal.
  • Keratoconus
    Progressive protrusion and thinning of the cornea
  • Eye diseases
    Involving any part of the eye
  • Diabetes
    Diabetes is not a contraindicaton for laser correction


Advantages of LASIK:

  • Helps to rid the patient of spectacles and contact lenses
  • Quick and safe procedure done under local topical anaesthetic
  • Both eyes are done at the same sitting
  • Recovery is quick
  • Long term side effects are minimal
  • The corneasis not weakend as compared to the old Radial Keratotomy procedure


Post-Operatively:

  • The eyes are covered with a transparent plastic shield for the first night. This is only a precautionary measure.
  • Antibiotic drops are used for a week afterwards.
  • The vision will be slightly blurred for the first few days after the operation, but usually patients are able to perform their daily activities the day after the operation.
  • Light sensitivity and glare at night normally disappear within six months.
  • If there is regression, enhancements can be done within three to six months after the operation.
  • Care must be taken not to rub the eyes.
  • No contact sport for three months.
  • No swimming for ten days post-operatively
  • No deep sea diving for one month post-operatively
  • Normal exercises such as running, aerobics, gym training may be started within two days.
  • No mascara or eye liner for one week.
  • Follow-up appointments will be scheduled as required


Risks & Complications:

  • Over-correction & under-corrections. Though these occur in less than 15% it depends on the initial refraction.
  • The higher the refractive error is the greater the chance of having under-correction. Enhancements may be done three months or later if the cornea is thick enough.
  • Infection. There is a small risk of infection, but antibiotic drops are instilled after the procedure and for a week after the operation.
  • Night glare. This is normally present for the first few months after the operation but usually is settled by four to six months. A degree of night glare may persist depending on the optical zone of the laser which is required for the specific treatment This complication has all but been eliminated by using the most modern type of laser at the Pretoria Eye Institute since 2005.
  • Haze. The incidence of haze for Lasik is very low. For PRK it is higher and that is why surgeons at the Pretoria Eye Institute prefer to do Lasik.
  • Post-Operative pain. This is usually not a problem, sone patients may experience varying degrees of discomfort. If the eyes are painful one should take normal pain killers & lie down with the eyes shut. Normally by 24-48 hours all discomfort has been cleared up.
  • Corneal flap complications. The incidence of this is small. They include flaps that are too small or short, inadeqaute thickness, inadeqaute quality & smoothness, or a loose flap. If one of the above occurs surgery is normally abandoned after replacing the flap. A few months later the procedure can safely be repeated.
  • Epithelial ingrowth. This occurs when surface cells grow in underneath the flap. Minor degrees of this are not treated and do not cause problems, but if there are large areas the flap is lifted and the cells are scraped .


Frequently Asked Questions:

  • Is Lasik a painful procedure?
    It is done under topical anaesthetic & sedative. There is normally a feeling of pressure but pain is rare.
  • What is the long-term effect after Lasik?
    There have been extensive clinical trials and so far no adverse long-term effects were found.
  • What are the risks of the Lasik procedure? Can I go blind?
    The risks are minimal. There have been no reported cases of blindness after Lasik surgery at the Pretoria Eye Institute and extremely rear anywhere else if any.
  • If my eyes regress after having Lasik surgery, can I wear spectacles or contact lenses again?
    It may be worn after the surgery. It will not harm the cornea.
  • May I watch TV, work on the computer and read after the Lasik surgery, or will it hurt my eyes?
    You may continue doing all of the above. It will not harm your eyes.
  • When may I start driving my car after the Lasik procedure?
    Most patients are able to start driving their car one day after the surgery if you feel comfortable doing so.
  • Will Lasik surgery prevent me from having to wear reading glasses later on in life?
    No, you will still need to use reading glasses. This occurs after the age of approximately 45-50 years of age. It is due to normal physiological changes of the eye as the lens starts to age.
Any other questions can be directed to us via email