PRK (Photorefractive Keratectomy)
PRK was the first laser refractive surgery approved by the FDA and has been performed for more than 24 years. PRK differs from LASIK in that no flap of tissue is created prior to resculpting the cornea with the excimer laser. This makes PRK a good option for patients whose corneas may be too thin for LASIK or have a curvature that might make creating a flap unsafe. PRK may also be a better treatment for patients with moderately dry eyes. Creation of a corneal flap with LASIK induces a temporary dry eye which can worsen a pre-existing dry eye. Since PRK doesn't involve creating a corneal flap, there is quicker recovery with respect to dry eye. PRK can be used to treat nearsightedness, farsightedness and astigmatism.
PRK is a safe, viable alternative to LASIK for many patients. Nearly 2 out of 10 surgeries performed at Flaum Eye Institute Refractive Surgery Center are PRK. Dr. MacRae uses the same Technolas excimer laser to perform PRK and LASIK. Our pre-operative evaluation is identical as for LASIK including the use of Zywave wavefront sensing technology.
The team at Flaum Eye Institute Refractive Surgery Center recently completed a one year clinical trial studying the difference between PRK and LASIK. A series of patients underwent PRK in one eye and LASIK in the other and were followed for one year. This taught us that, in the long term, PRK and LASIK are very equivalent procedures in so far as outcomes are concerned. The primary difference is the speed of visual recovery and the comfort in the first few days after surgery. PRK has a more uncomfortable recovery for several days after surgery.
On the day of surgery
- Remove contact lenses at least 24 hours prior to surgery.
- Remove all make up.
- Eat a light meal.
- Wear comfortable clothing.
- Plan to be at Flaum Eye Institute Refractive Surgery Center for an hour and a half.
- Bring a driver.
- Rest and follow all Post-Procedure Activities and Restrictions (see below)
What to Expect During Surgery
During PRK, the top cell layer of the cornea is gently removed to prepare the eye for treatment. Originally, this top layer, or epithelium was mechanically removed by the surgeon. Today, a variant of PRK originally known as LASEK (Laser Epithelial Keratomileusis) uses a dilute alcohol solution to loosen the epithelium prior to removal. The excimer laser is then used to resculpt the shape of the cornea reducing your refractive error in the same fashion as is done after flap creation with LASIK. Anesthetic drops are used which numb the eye making the actual procedure painless.
After the treatment, a contact lens is placed on your eye as a bandage for four to six days while the epithelium of the cornea re-heals. This top layer is one of that fastest healing tissues in the human body. In an optical sense, the epithelium is the first surface that light focuses through as it enters your eye.
What to Expect After Surgery
It is common to experience varying degrees of discomfort beginning 30 to 90 minutes following the surgery as the numbing drops begin to wear off. Many patients describe this sensation as feeling like an eyelash is in the eye or lodged beneath a contact lens. The second day after treatment may be the most uncomfortable. You can expect to be very light sensitive and should not plan on going to work or being very active. This rarely lasts more than a few days and is a normal part of the healing process. As with most things of this sort, the degree of discomfort varies from patient to patient. You’ll be given eye drops and, if needed, oral pain medication to keep you comfortable through these first few days.
Dr. MacRae will put a contact lens in your eye directly after surgery to act as a bandage. It is important not to remove the contact lens for any reason because without it, the pain may increase. A contact lens that has fallen out accidentally should NOT be reinserted. If you do so, the contact lens has likely been contaminated therefore increasing the risk of infection. Instead, continue using your eye drops, gently tape the eye closed and call us so that we can determine if a new contact lens should be placed on your eye. The bandage contact lens in combination with lubricating drops, prescription eye drops (to be used as directed by the surgical team) and mild, oral analgesics should provide relief.
Also, you can place a cold washcloth, gel pack or an ice pack over the eye to help relieve discomfort (10 minutes on, 10 minutes off and repeat as needed). In most cases, the bandage contact lens will be removed by the doctors on the 5th or 6th postoperative day. After this, the eye will become more comfortable and your vision will begin to improve.
In the first day or so after PRK, vision in the treated eye may be good. As the top surface layer heals, your vision may actually get slightly worse. This is expected and due to the slightly “bumpy“ nature of the new epithelium under the bandage soft contact lens. Once the tissue is well healed and the bandage lens is removed, every time you blink, your lid will act to smooth out and polish the epithelium and the quality of your vision will improve. It may take two weeks or more for this crispness to return.
Common Symptoms After PRK
You may experience watery eyes, a runny nose, light sensitivity and eye redness during the early postoperative period. This is normal and is caused by the post-surgical eye irritation. You may be farsighted immediately following surgery, which will cause "hazy" vision, especially up close. Expect your distance vision to clear before your reading vision. If you are over 40, your age will determine when and if your reading vision will return. Patients over 45 years of age usually will need reading glasses, even if a monovision correction has been chosen. It is normal for vision to go in and out of focus particularly for the first couple weeks following surgery but should improve substantially by one month. Although visual recovery is slower for some patients, most experience very good vision by one to two months after treatment.
Some patients have dry eye symptoms causing a sandy sensation or eye tenderness. This may persist for several weeks following the surgery and is best treated with frequent artificial tear use.
Night glare, commonly described as halos or starbursting, is often reported during the first several weeks following surgery and is related to the normal healing process. This gradually decreases so that it bothers very few by six months and even fewer by one year. Infection is very rare but is the most serious problem that can present after PRK.
It is important to be evaluated immediately if you experience pain, eye redness, sudden blurred vision and/or discharge.
Follow Up Appointments
It is very important that you make it to all of your postoperative examinations so that if any changes or complications arise, they can be addressed immediately.
Post-Procedure Activities and Restrictions
- It is best to keep both eyes closed and rest as much as possible for the remainder of the day following your surgery. Sleep will speed your recovery.
- Read and watch TV in moderation for the first few days.
- Showers and baths are fine but try to keep your eyes closed and avoid getting water directly in the eyes the first week after surgery. When drying off, pat the outer eyelid and surrounding areas of your face gently with a towel. Avoid directly rubbing or bumping your eye.
- Do not go swimming, use a hot tub, spa or whirlpool for at least 2 weeks to reduce the risk of infection.
- Resume driving only when advised by your doctor and when you feel confident and safe. This generally occurs after one week. However, your vision may fluctuate for the first several weeks so it is important to use good judgment.
- Most people can return to work one week after surgery.
- Do not wear eye makeup, lotions, cologne or aftershave for 1 week.
- Wear sunglasses for comfort while outdoors.
- Avoid dirty and dusty environments for 1 week.
- Most patients can return to their normal exercise routine after a few days as your comfort permits.
- After your doctor has removed the bandage contact lens, do not wear a contact lens in your treated eye(s) unless instructed to do so by your doctor.