Photorefractive keratectomy (PRK) is a laser surgery to improve vision, and to reduce—sometimes eliminate—the need for eyeglasses or contact lenses. PRK can treat both nearsightedness (myopia) and farsightedness (hyperopia) with or without astigmatism (blurry or distorted vision). PRK received Food and Drug Administration approval in 1995. Although PRK is an older technique than LASIK, we still use it in when LASIK is not appropriate due to an underlying eye condition, such as chronic dry eyes, or when a cornea flap is not recommended. It is also called a flapless LASIK.

Another important difference between PRK and LASIK is that PRK requires more time to recover. After PRK, immediate recovery is usually one to two weeks. Most of the vision improvement happens in the first month. But you may find you see a little better over the following few months. The PRK procedure offers the following benefits:

• No blade or incision
• Safe and effective treatment if you don’t qualify for LASIK
• Better alternative if your job or lifestyle cannot accommodate a corneal flap
• Minimal to no haze, glare, or halos

Initial Consultation

First, we meet with you to perform a detailed eye exam. We will measure the curvature of the eye and check corneal thickness, pupil size, tear production, and stability of the refractive error. We will design your treatment based on these measurements. You must stop wearing your contact lenses for at least two weeks prior to this appointment to ensure your eyes are in best condition for testing. This consultation is a good chance to ask all your questions and discuss any lifestyle changes you may need to make during the recovery period.

Standard PRK

After numbing the eyes with eye drops, the surgeon will remove the protective surface layer (epithelium). The amount of tissue we remove is about the thickness of a human hair. The epithelium will regrow within five days.

After removing the epithelium, the surgeon positions an excimer (STAR S4 IR Excimer Laser) laser beam over the eye. This laser is a very precise medical laser that creates a highly focused beam of cool ultraviolet light to gently reshape the cornea. We direct the light pulses to shape the eye to achieve the desired correction. Your refraction measurements will guide the excimer laser reshaping procedure (called photoablation). The reshaping generally takes less than 60 seconds. The procedure is painless.

Wavefront-Guided or Custom PRK

Wavefront-guided PRK treats the same conditions as standard PRK. The main difference is that with wavefront-guided PRK, we create a detailed 3D map of the visual imperfections of the eye using wavefront eye-mapping technology. This approach is 25 times more precise than the measurements used to write standard prescriptions for eyeglasses or contacts. It allows the surgeon to reshape the cornea based on your anatomy. As a result, wavefront offers superior results, bringing it closer to 20/20 vision or better. The rest of the procedure is much the same as with standard PRK.

The results of PRK are irreversible. While it happens rarely, if the procedure over- or under-corrects your vision, you will need a second procedure to make adjustments.

Candidates

Your ophthalmologist will perform a thorough exam to determine if you are a candidate for PRK. It is likely you are a good candidate for the PRK procedure if you:

• Are at least 21 years of age.
• Have acceptable refractive errors: nearsighted up to -12.00 or farsighted up to +6.00. Your level of astigmatism can be as high as 6.00 diopters.
• Have healthy eyes and no corneal abnormality (such as scars, infection, or abnormal thinning).
• Have a stable eye prescription (with documented evidence that your refraction did not change by more than 0.50 to 1.0 diopter over the past two years).
• Have chronically dry eyes or thin corneas.
• Have a job or participate in activities (like sports) where a corneal flap is contraindicated.
• Not pregnant or nursing.

PRK should not be performed on people with:

• An unstable (changing) refractive error
• A history of autoimmune disease (such as lupus or HIV) because it has been shown that these patients may heal poorly
• A history of corneal dystrophy (inherited degenerations of the cornea)
• Past viral infection by herpes simplex or herpes zoster (shingles)
• Advanced glaucoma
• Uncontrolled diabetes