As an increasing number of people are taking advantage of technology to correct vision, LASIK has, by far, received the most notice. It has been the subject of television, newspapers, and magazines reports, and has become a familiar word to most Americans. But there is another laser procedure, one that, although not for everyone, has distinct advantages, and can offer the opportunity to see well without glasses or contact lenses. It is called Photorefractive Keratectomy, or PRK.
What is prk and How does it differ from Lasik?
PRK was invented in the 1980s, and widely practiced worldwide before receiving FDA approval in the US in 1995. PRK cannot correct presbyopia, the age-related loss of flexibility of the eye’s focusing muscles that ultimately cause the need for reading glasses or bifocals. PRK uses the excimer laser’s cool, ultraviolet light beam. Now the difference between LASIK and PRK begins. While a microkeratome is used to gently create a corneal “flap” that is left attached and folded back for LASIK, PRK does not require the creation of a flap. Simply, based on previous testing, microscopic amounts of corneal tissue are removed, or ablated, by the excimer laser in an effort to restructure the cornea and thus better control the focusing of light on the retina. Due to the extreme accuracy of the excimer laser, a single cell of microscopic corneal tissue can be removed without damage to adjacent cells. Dr. Sondheimer performs the procedure on an out-patient basis. The actual laser surgery itself typically takes no more than a minute or two per eye. The eye is numbed and you remain awake and comfortable the whole time. All testing is pain-free. If you are a contact lens wearer, you will be asked to return to wearing glasses. Leave soft contact lenses leave out 2 weeks before the procedure.
What can prk surgery help fix?
PRK and the excimer laser can benefit both nearsighted (flatten a too-steep cornea) and farsighted (make the cornea steeper) patients. In some cases, the excimer laser may also be used to smooth the irregular curvature of a cornea, the cause of astigmatism.
What are the advantages of PRK?
Typically Dr. Sondheimer may recommend PRK Surgery to his Chicago patients in order to retain the integrity and strength of the eye. Dr. Sondheimer may also recommend PRK for patients with very dry eyes or thinner corneas — individuals who are not LASIK candidates. Because the excimer laser can “sculpt,” advanced technology can reliably treat nearsightedness, farsighted, and astigmatic eyes.
Who is a good candidate for PRK surgery?
PRK is appropriate for people between 18 and 59 whose eyes are healthy and have stopped becoming more myopic each year. If their eyes have significant eye diseases such as cataracts, diabetic eye disease, or keratoconus., they should not have PRK. Patients should have realistic expectations about what PRK can do for them. Each of our patients have a very thorough eye evaluation to make sure that they are good candidates for refractive surgery and to determine which procedure is best for them.
- has a prescription of +3.0 or less to 10.0 diopters or less.
- may have astigmatism.
- has no problems healing quickly.
People who are not considered good Chicago PRK candidates include individuals who are pregnant, have a pacemaker, are under 20 years old, have active eye, collagen or vascular disease, or whose glasses prescription changes several times in one year. Prior to PRK surgery, testing will be done in order to accurately establish a treatment pattern for the laser to ensure an optimal outcome. Typically, you will have:
- a complete eye examination which will include a history of any eye problems you have experienced;
- Corneal topography (this maps the ³hills² and ³valleys² of your eyes);
- pachymetry; and
- axial length measurements.
After surgery, your eye will be fit with a special contact lens to promote healing, and you will rest for a few minutes before returning home. Most people experience little or no discomfort. Some people return to work the next day, but Dr. Sondheimer prefers you rest at least three days before resuming an active schedule. Vision takes longer to recover than LASIK. Most patients return to work 5 days after having PRK and vision improves over a period of weeks. He also recommends patients refrain from strenuous activities or exercise for one week. During this time it will be necessary to refrain from rubbing the eye, and to guard against water, soap, shampoo or make-up from getting in the eye.
Patients are asked to return at least one day, one week, one month, and three months after PRK. Before your procedure, the benefits, risks and any potential complications of PRK will be thoroughly explained to you, and you may (and should!) contact Dr. Sondheimer with any questions you may have.