Your eye doctor at Kanata Optometry Centre can tell you if you are a candidate for laser vision correction. If you are interested in laser vision correction let your doctor know at the beginning of your next examination. If you are a new patient call or request an appointment online today.
Refractive surgery is performed by a trained Ophthalmologist, usually at a hospital or laser vision centre. Your eye doctor at Kanata Optometry Centre can set up a consultation with a laser centre and perform your pre-operative and post-operative care.
To be eligible for refractive surgery you must:
- Be 18 years of age or older
- Not have had a significant change in your glasses or contact lens prescription for the last 12 months.
Contraindications for surgery include but are not limited to:
- Diabetes.
- Pregnant or nursing mothers
- Certain rheumatological conditions
- Pacemakers
- Thin cornea
- Flat corneas
- Significant dry eye disease
- Recurrent or active eye diseases
If a person has a refractive error, then light is not focusing properly on the retina in the back of the eye. People who have refractive errors may consider refractive surgery as an alternative to wearing corrective lenses. Refractive surgery corrects refractive errors by altering the shape of the cornea and thus the way the eye focuses light internally. The goal of refractive surgery is to reduce or eliminate a person’s dependence on eye glasses or contact lenses. Although refractive surgery cannot guarantee 20/20 vision for every person, it can significantly improve eye sight and generally reduce and in some cases eliminate the need for corrective lenses.
Refractive errors that can be corrected with refractive surgery include myopia (nearsightedness), hyperopia (farsightedness) and astigmatism. The range of refractive errors that can be corrected with refractive surgery varies depending on the type of refractive error.
Refractive Surgery
Photo-Refractive Keratectomy (PRK) was the first procedure using the Excimer laser. With PRK, the outer layer of the cornea, called the epithelium is gently removed. The laser is then used to reshape the cornea, which is the clear covering of the eye. The epithelium regenerates over the treated area within days. PRK achieves excellent results especially for patients who may have thin corneal thickness measurements. The main drawback to PRK is that there is some eye pain or irritation for the first few days after surgery.
Laser In-Situ Keratomileusis (LASIK) also uses the Excimer laser and it the most common type of refractive eye surgery. With LASIK, patients experience faster vision recovery and minimal eye discomfort from the procedure. A tiny oscillating blade known as a microkeratome is used to create a thin flap of corneal tissue. The flap is folded back and the laser is applied to the exposed inner corneal tissue. The flap is then repositioned, where it bonds tightly without the need for stitches.
Intralase SBK (sometimes referred to as simply “SBK”) is a method of Laser Vision Correction that employs an infrared beam of light to make an ultra-thin flap (much thinner than the flap created during Laser Assisted In-Situ Keratomileusis (LASIK)) created through a process called photodisruption.This process uses highly focused, unimaginably short duration laser pulses to divide material at the molecular level without impacting the surrounding tissue. The beam of laser light is focused to a distinct point, creating a microscopic bubble of carbon dioxide and water vapor. Thousands of these bubbles are precisely positioned to define the flap’s dimensions, as well as the location of the hinge. The surgeon can then lift the flap to permit treatment by the laser. When treatment is complete, the flap can be accurately repositioned, thanks to its beveled edge.
Instead of using a blade to create the flap, a laser can be used to make the flap as well. Commercially known as Intralase, the laser (different from the laser that reshapes the cornea) can create a thinner, more uniform flap with potentially less complications than the microkeratome. This can lead to better visual recovery.
PRK, SBK and LASIK are very quick and accurate surgeries. However, they may, in limited instances, produce visual aberrations in the form of glare or haloes under dim lighting conditions and dry eye syndrome. Roughly five per cent of patients who undergo PRK, SBK or LASIK will need to undergo additional surgical correction or enhancement.
In the last few years there has been the release of wavefront-guided or custom PRK/SBK/ LASIK. Custom laser eye surgery is an advancement of the standard laser treatment and provides a more personalized treatment that is unique to each patient. Advantages of the custom treatment include improving the quality of vision after surgery and decreasing the incidence of glare of haloes. The custom laser eye surgery is now being marketed quite heavily due to its inherent benefits.
The next type of refractive eye surgery is clear lens extraction (CLE). This procedure does not involve a laser and is the same as cataract surgery. With CLE, the normal clear lens of the patient is removed from the eye and is replaced with an artificial lens. The artificial lens provides proper focusing power to improve vision. CLE is more invasive than the above surgeries and is generally reserved for patients with extremely high spectacle prescriptions.
Like with all surgical procedures, refractive eye surgery has the risk of complications. Fortunately, the likelihood of vision loss is minimal. Your optometrist or ophthalmologist will be able to offer an informed opinion regarding your candidacy for any of the refractive surgery options available.