As the previous article stated, there are several types of laser eye surgery: PRK, Lasik and Lasek procedures.

LASIK usually has less post-operative pain, and there is a greater risk of complication due to the cornea being cut into. This includes:

• Mild to significant dry eyes, which can affect vision;
• Poor quality of night vision due to halos and glare, thus affecting the ability to drive safely at night;
• Corneal ectasia, a serious condition caused by the weakening and bulging of the cornea. Severe cases of this condition can require a corneal transplant or implant.

Both the LASIK and PRK procedures carry the risk of corneal infection, known as infectious keratitis. This infection can result in a significant loss of vision. LASEK surgery reduces the risks such as weakening of the eye and dry eyes. As with any other surgical procedure, complication risks are increased for people with certain health conditions and/or lifestyles. When contemplating eye laser surgery, have a detailed consultation with the surgeon about:

• Your medical history and current health conditions. Make sure the surgeon is made aware of such conditions (yours and family history) as lupus, diabetes, keloid formation and any eye diseases, i.e. herpes simplex, glaucoma, dry eyes, eyelid infections, and/or previous eye surgeries.
• Your current lifestyle. For people who engage regularly in sports, where it is likely to be hit in the face, after LASIK there is a risk that the flap could dislocate. This risk remains for years after the laser surgery.
• Your career plans. Certain occupations (i.e. pilot, police officer) have specific vision requirements, most of which can be obtained through laser surgery. It is advisable to consult with not only the surgeon, but with members of the occupation to make sure the requirements are met.

As well as considering the benefits and risks of laser eye surgery, it is important that people are realistic about what they will achieve through the procedure. As people age, so do their eyes, it is possible that in the future some people may need reading glasses or other corrective eyewear again, especially those over the age of 40. There also is the possibility of having to have a second procedure if the right amount of correction is not achieved through the first surgery.

Cost is also a consideration for eye laser surgery. Before considering this option, consult with your health insurance professional to see what they cover. Most health insurance does however cover the costs of contact lenses and/or corrective eyewear. Check your group health insurance and/or individual health insurance plan.

Every year, thousands of Canadians contemplate laser eye surgery in order to correct their vision. This surgery is done in anticipation of the person no longer being required to use contact lenses and/or prescription glasses in order to have better vision. Canadians who are contemplating laser surgery should be well informed of not the benefits of these procedures, but also the risks.

Laser eye surgery is most commonly used to correct vision problems such as:

• Myopia, also known as near-sightedness;
• Hyperopia: also known as far-sightedness;
• Astigmatism: when vision is distorted when looking at objects at any distance;
• Presbyopia: when the person is unable to focus on nearby objects.

All of these vision conditions are caused by problems with the eye focuses an image on the retina (the light-sensitive layer at the back of the eye). A large part of the eye’s ability to focus is dependent on the shape of the cornea (the clear front surface of the eye). A surgeon will use a laser device to make permanent changes to the shape of the cornea. Most often used is the Excimer laser, which produces a ultraviolet light beam which vaporizes tissue, thus altering the shape of the cornea. This usually corrects mild to moderate refractive errors in the eye.

There are several types of laser eye surgery that are commonly performed in Canada:

1. PRK (Photo-Refractive Keractectomy): the outer layer of the cornea is removed with a surgical blade or blunt instrument. A computer-guided laser beam is then used to vaporize tiny amounts of tissue that are under the surface of the cornea. This procedure removes just enough tissue in order to reshape the cornea in a way that the vision is now corrected. The healing process of this procedure is usually completed within one week.
2. LASIK (Laser Assisted in situ Keratomileusis): This procedure is more complicated than PRK. A flap is cut in the cornea with either a sharp blade or a laser. The flap is then lifted and a computer-guided laser removed specific calculated amounts of tissue from the inside layers of the cornea. The flap is then put back. Wavefront technology may be used in this procedure, wherein a detailed map of the eye is produced. The healing time for this procedure is generally less than the time for PRK.
3. LASEK (Laser Epithelial Keratomileusis): This procedure is a variation of both PRK and LASIK. The outer layer of the cornea is cut and then alcohol is used to loosen and lift it in a single layer. A laser beam is then directed at the tissue under the epithelium. This procedure is best suited to people who have vision problems that require minor correction; the healing period is usually two weeks. As with any surgical procedure, there is a risk taken (though quite small), that complications can arise. Each certain procedure does carry with it a small percentage of complications. For those contemplating PRK, the risks include: • Moderate to severe pain for the first several days; • Hazy vision during the healing; this generally will clear within the first week after the surgical procedure; • Regression. In some cases the eye can regress to its previous refractive error, this usually will occur during the first 6 months. In these cases the person may need a second (enhancement) surgery, or may have to once again wear corrective eyewear or contact lenses.

See our next blog article for the conclusion about laser eye surgery.