PRK (photorefractive keratectomy) is a type of refractive surgery to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
What is PRK
PRK is surgery which corrects varying degrees of astigmatism, nearsightedness and farsightedness vision by reshaping the cornea. With PRK the outer surface of the cornea is reshaped using the excimer laser (a cold laser that does burn tissue but sculpts and reshapes by removing one tiny layer at a time). PRK works by reshaping the cornea using an excimer laser, allowing light entering the eye to be properly focused onto the retina for clear vision
Astigmatism occurs when the cornea is oblong, or football-shaped. This causes light rays to focus on two points in the back of the eye, instead of just one (which is normal). For astigmatism patients, we use the excimer laser to make the cornea more spherical, creating one point of focus.
Nearsightedness, also known as myopia, occurs when the eyeball is a little longer than normal from front to back, which causes light rays to focus at a point just in front of the retina, instead of directly on it. We treat this common symptom by removing tissue from the center of the cornea with the excimer laser, slightly flattening its shape. This helps to focus light rays directly on the retina.
Farsightedness, also known as hyperopia, occurs when the eyeball is slightly shorter than normal from front to back, which causes light rays to focus at a point just behind the retina, instead of directly on it. For patients with farsightedness, we use the excimer laser to remove tissue from the outer edge of the cornea, making it slightly steeper and allowing light rays to focus directly on the retina.
What To Expect
For those who are tired of relying on their eyeglasses or contact lenses, Photorefractive Keratoplasty surgery can be an ideal solution. we strive to ensure that all our PRK patients will be able to enjoy performing their daily activities without corrective lenses. Over the years, PRK has come to be recognized as very safe and effective. Like any surgical procedure, complications from PRK can occur (although very rarely). For this reason, We use the latest in diagnostic technology to conduct thorough pre-operative examinations with each and every patient. We r understands that PRK is not for everyone and carefully screens each individual in order to ensure the best possible results. Nearly 100% of people who undergo PRK surgery are completely satisfied with their improved vision.
If you are interested in laser vision correction and believe you are a potential candidate, please do not hesitate to contact us for right away to schedule a consultation. This initial screening will help you to make an educated decision on whether or not LASIK or PRK is a potential solution for your vision problems. For us it is imperative we ensure that each patient has all of his/her questions answered to their satisfaction prior to undergoing PRK surgery
- Procedure time: about 10 minutes per eye
- Typical results: 20/20 vision without glasses or contact lenses
- Recovery time: several days to several weeks
When is PRK surgery recommended; Is PRK for you?
If you are fed up with having to rely on contact lenses or eyeglasses to see clearly, PRK surgery may be for you. We will advise you to determine whether or not PRK surgery is for you. Here are some general guidelines that can help you determine if you are a candidate:
- You are at least 18 years old.
- You are suffering from myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
- Your corneas are typically too thin for LASIK surgery.
- You must have stable vision for at least one year (young adults are susceptible to changes in their contact lens or eyeglass prescription; vision tends to stabilize in the 20s).
- You must have healthy eyes. You must have no major abnormalities of the cornea or external eye. Any condition that affects how well your eyes would heal after PRK must be addressed prior to surgery.
On the day of your PRK surgery, you will arrive at the Eye Centre about an hour prior to the procedure. Preparations for your PRK procedure will commence shortly after you are checked in. Patients are instructed to clean their own face and eyes before arriving for surgery. A mild sedative is also offered to every patient to help calm the nerves. First, anesthetic eye drops will be used to numb your eyes (no injection is necessary during this step). Once the anesthetic has taken effect and your eyes are completely numb, an eyelid holder is put in place to prevent you from blinking during the short PRK procedure. The anesthetic ensures that you are comfortable and relaxed during the procedure.
First, your eye surgeon removes a central area of corneal epithelium with an alcohol solution, a “buffing” device or a blunt surgical instrument. Next, an excimer laser is used to precisely reshape the curvature of your cornea’s surface. This computer-controlled, highly specialized laser delivers pulses of cool ultraviolet light that remove microscopic amounts of tissue in a precise pattern. A soft contact lens “bandage” is then placed on the cornea to help protect your eye. New epithelial cells grow back in five days typically, after which the bandage contact lens is removed by your eye doctor.
PRK is a short, painless procedure and, depending on how much correction is required, is usually completed within a few minutes. You may experience some pressure during the procedure, but no pain. Blurry vision is common for a day or two, but most people achieve functional vision before one week following PRK surgery. You will need to make arrangements for a ride home after the procedure because a bandage contact lens is placed over the cornea. The first few days after surgery, some discomfort may persist as the epithelium (the outer surface of the cornea) heals. Topical drops and oral pain medication are often used to help with this. The majority of PRK patients are able to resume their normal daily activities within a few days after surgery.
Results of PRK
PRK laser eye surgery has been performed overseas since the 1980s and in the United States since 1995 and has a very high success rate. It has undergone significant advancements during this time and remains the treatment of choice in certain circumstances. Most people achieve 20/20 vision after PRK surgery, and nearly all patients achieve 20/40 visual acuity or better. Some patients may still need to wear eyeglasses or contact lenses, but the prescription will be significantly lower than before the procedure. While unlikely, you may need additional or enhancement surgery to improve your vision further or to correct a gradual worsening of your eyesight over time. Reading glasses also may still be required after PRK surgery once you hit your 40s, due to an age-related loss of near vision called presbyopia. The FDA currently is monitoring clinical trials for a permanent surgical correction of presbyopia.
What are the risks?
Post-operative PRK complications are rare and can include mild side effects such as dryness, glare, and halos may be experienced but usually diminish within a short period of time. Eye drops are usually used to help the healing process. As is common with any surgical procedure, each patient heals differently.
PRK Excimer Laser