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Laser Eye Surgery FAQ

This booklet contains general information that is not specific to you. If you have any questions after reading this, ask your own physician or health care worker. They know you and can best answer your questions.

For more information, please contact: Gail Kayuk, Clinical Coordinator, at 613-737-8899 ext. 78657 or Nancy Whyte, RN at 613-737-8899 ext.71548.

What is laser eye (or excimer laser) surgery?

Laser eye (excimer laser) surgery is a treatment to correct nearsightedness, farsightedness or astigmatism. The surgery may reduce or eliminate the need for contact lenses or glasses. In a normal eye, the front of the eye (cornea), the lens of the eye and the shape of the eye focus light to form an image on the back inside surface of the eye (retina).

Nearsightedness (myopia) occurs when light falls in front of the retina instead of on the retina. This causes the image of distant objects to appear blurred.

Farsightedness (hyperopia) occurs when light falls beyond the retina. This causes images of near objects to appear blurred.

Astigmatism occurs when the eye shape is not round but shaped like a football. This irregular shape causes images to appear blurred.

Astigmatism can be present with either farsightedness or nearsightedness.

How does excimer laser surgery correct vision?

Short pulses of invisible ultraviolet light remove a small amount of tissue from the cornea to correct the curvature. The amount removed is typically less than the thickness of a human hair. By correcting the curvature of the cornea, images are better focused on the retina and the images are clearer.

What is iLASIK?

iLASIK (laser-assisted in situ keratomileusis) is a refractive procedure in which the femtosecond laser is used to create a thin flap from the surface of the cornea. The corneal flap is 100-140 microns thick. The corneal flap is then lifted, and the excimer laser is used to re-shape the remaining cornea to produce the desired correction. The flap is then re-positioned on the corneal surface over the treated area.

What is PRK?

PRK (photorefractive keratectomy) is a surface refractive procedure in which the epithelium (surface layer of the cornea) is removed using: 1. the Excimer laser (PRK); 2. a rotary brush (PRK); 3. with the aid of 20% alcohol (EK-PRK); or 4. with an Epi-microkeratome (Epi-PRK). The excimer laser is then used to re-shape the cornea to produce the desired correction. At the completion a contact lens or an eye patch is applied.

What are the advantages of having the iLASIK procedure performed instead of PRK?

The reported advantages are reduced post-operative discomfort in the first 3 to 5 days, a faster return of vision, less use of steroid drops and less chance of corneal haze.

What are the disadvantages of having the iLASIK procedure performed instead of PRK?

The disadvantages of the iLASIK procedure are the complications related to the presence of the corneal flap. The safety of using the iLASIK procedure for patients with a high degree of myopia has not been established.

What is a Wavefront measurement?

A wavefront measurement is a new tool for the determination of the visual performance of the eye. The method records the optical defects of the eye and calculates a customized treatment (CustomVue) for the excimer laser. This method can be used with PRK or i LASIK. A CustomVue treatment differs from conventional laser eye surgery, in that, it takes into account not only your eyeglass prescription, but also all of the other optical defects in the eye.

Who can have laser eye surgery?

People 21 years of age and older with healthy eyes and stable vision are possible candidates for this procedure. A visit to an eye doctor (ophthalmologist) will help determine if laser correction for nearsightedness, farsightedness or astigmatism is right for you.

How safe is it?

Millions of patients in Canada, the United States, Europe and Asia have had this treatment performed on them successfully for nearsightedness, farsightedness and astigmatism. Here at the University of Ottawa Eye Institute, The Ottawa Hospital (General Campus), 99% of patients achieve results of 20/40 or better (sufficient vision to obtain a driver's license without restriction in Ontario ) and over 90% of patients achieve results of 20/20 or better. There may be the need to repeat the surgery if the eye regresses or becomes nearsighted or farsighted again. The amount of prescription retreated is usually much less than the original prescription.

What happens before laser eye surgery?

A consultation visit at the Eye Institute is the first step. New patients watch an informative videotape about laser eye (excimer laser) surgery and the different surgical methods will be discussed. Initial readings are taken to determine whether or not they are a candidate for laser eye surgery.

The patient arranges a second visit with the ophthalmologist when they decide to proceed with the surgery. Preoperative tests are done during this visit and the surgical method (PRK or iLASIK) is established. Patients who wear contact lenses must not wear their contact lenses for a minimum of two weeks prior to this visit to allow the cornea to return to its normal shape. We often perform surgery a week after this visit. The physicians will schedule surgery to accommodate the patient's schedule wherever possible.

What tests are done during the preoperative visit?

A thorough eye examination is done to decide whether the patient's eyes are healthy and suitable for laser vision correction. Patients read an eye chart which helps show how well they see with and without glasses. Eye drops will be used to anesthetize the eyes and to dilate the pupils for this examination. Tests are done which determine the shape of the cornea, the thickness of the cornea, the optical defects in the eye and the pressure inside the eyes. These tests are painless.

We recommend patients arrange a ride home and bring sunglasses to wear after this visit. The anesthetic drops wear off in 30 minutes and the dilating drops take approximately 3-4 hours to wear off.

How long does laser eye surgery take?

The surgery itself takes only a few minutes but plan on being at the Eye Institute for about two hours. On the day of surgery, we repeat the eye examination to make sure the vision has not changed. Medication is given to help the patient relax and for pain. These drugs may make the patient feel groggy. The eye is frozen with eye drops before the surgery. We do not allow the patient to drive following surgery. Patients must bring someone with them to take them home. Following the iLASIK procedure, the patient will be asked to remain an additional 30 minutes after the surgery to confirm the proper positioning of the corneal flap.

Do patients wear an eye patch following surgery?

Not usually. The physician inserts a contact lens with no prescription in the eye following the surgery in patients with PRK and occasionally after iLASIK. Vision will be blurry during the first few days. This is normal. Patients who cannot tolerate wearing a contact lens will have the eye patched instead. A protective eye shield is also applied directly after surgery and worn home and removed the next morning. It is also worn while sleeping for 1 week after surgery.

Can both eyes be treated on the same day?

Yes, both eyes are treated on the same day. Patients do have the option of having the eyes treated on the alternate days if they choose to. Usually the second eye being treated one to seven days after the first.

What is the follow-up appointment schedule after laser eye surgery?

For PRK , the physician sees the patient on a daily basis following laser eye surgery until the surface layer of the cornea is fully healed. The cornea will heal in between 4 to 7 days, but in some individuals it may take a little longer. For iLASIK the physician sees the patient the next day and possibly the next one to two days. Following this we see patients in the follow-up clinic at 1 week, and 1, 2, 3, 6 and 12 months after the surgery date.

I wear bifocals for driving and reading. After the surgery, will I still need to wear my glasses for reading?

There are different options available for patients over the age of 40. Many patients prefer to have both eyes corrected for the best possible distance vision and wear reading glasses when necessary. Others may wish to correct only one eye for seeing objects close-up and correct the other eye for distance vision. A trial of contact lenses with one eye corrected for reading and the other eye corrected for distance will help the patient to decide if this option, called monovision, will work for them.

What is the cost of the surgery?

The cost is $2000. for each eye. This amount covers the surgery and the follow-up visits at the Eye Institute for one year. We do not charge for the consultation visit or the preoperative evaluation. If a retreatment is required, there is no charge if this is done within the first two years. After the two-year period a small administration fee is charged to the patient. In addition, the patient will receive a prescription to fill for one set of drops. The other drops will be provided.

Will OHIP or extended health insurance plans cover the cost of this procedure?

Laser eye surgery for correcting nearsightedness, farsightedness or astigmatism is considered cosmetic surgery and, therefore, not covered by OHIP. E xtended health insurance plans may provide partial coverage . It is considered a deductible medical expense for income tax. OHIP will pay for phototherapeutic keratectomy surgery (PTK) as it is performed for therapeutic or medical reasons. PTK surgery is done to remove scar tissue on the cornea or to correct abnormalities of the cornea.