Photorefractive Keratectomy (PRK)

Photorefractive Keratectomy (PRK)

Photorefractive Keratectomy (PRK) is a laser procedure for correcting low to moderate amounts of nearsightedness, farsightedness, and astigmatism. Laser vision correction has become one of the most popular outpatient surgeries in the US. Still, this surgery may not be advisable for some people due to thin, misshapen cornea or other eye conditions. PRK might be a treatment of choice in such cases.

Prk Edmonton and Northern Alberta
Prk Edmonton and Northern Alberta

PRK is a technique in which the central portion of the outer layer/skin/mucosa of the cornea, called the epithelium, is removed, followed by reshaping or ablation of the underlying corneal stroma using the Zeiss MEL90 Excimer laser. This can be combined with Corneal Collagen Cross-linking. 

For the procedure, the eye is numbed/anesthetized with topical anesthetic drops. To perform PRK, the surgeon programs an Excimer laser to vaporize precise microscopic layers of tissue from the eye’s surface. By modifying the shape of the cornea, light rays can focus correctly within the eye to provide clear vision.

In most cases, only 10-20% of corneal tissue is removed, leaving the structural integrity of the cornea intact. The cool laser beam vaporizes tissue away, one microscopic layer at a time, without burning or cutting. Since the excimer laser light is created at a specified wavelength that does not pass through the cornea, no other part of the eye is affected.

After the corneal tissue has been removed by the laser, the surgeon places a soft bandage contact lens on the eye for 4-5 days to protect it and allow the epithelium to heal fully.

The laser correction usually takes only a few seconds per eye, although the patient is in the surgery suite for about 15-20 minutes.​

The cornea consists of different layers of tissue. The surface layer, known as the epithelium, is a soft, protective layer that regenerates quickly. The interior part of the cornea, known as the stroma, does not regenerate itself when removed or reshaped. Before laser correction, the surgeon removes this outer layer. Within a few days of the surgery, the epithelium regenerates itself, again forming a protective layer over the eye.

Potential side effects during this healing process include light sensitivity (it is recommended that sunglasses be worn while outdoors), occasional blurring, haziness of the cornea, and dryness.
Patients are given eye drops to manage the postoperative pain and help the eye to heal normally without forming haze/scar tissue. Visual recovery happens rapidly over the first few weeks, and it takes up to 3 months for patients to achieve full visual acuity.

Candidates for PRK must be at least 18 years old and in good health with stable prescriptions (for at least a year). However, to confirm the eligibility, a thorough examination is required.

PRK is often a good alternative for those who are not eligible for LASIK surgery. This includes patients with thin or irregularly shaped corneas that cannot tolerate contact lenses or LASIK procedures.

The Following Refractive Errors Can Be Corrected (Exceptions May Apply):
Myopia (nearsightedness): Up to -8.0 Diopters
Hypermetropia (Farsightedness): Up to +3.00 Diopters
Astigmatism: Up to 5.00 Diopters

Find out if Photorefractive Keratectomy (PRK) can correct your vision

At Visionmax Eye Centre, we do a thorough eye evaluation to determine if you can expect positive results from a PRK. Call our office at 780-452-4111 to schedule a consultation today.