PRK, or Photorefractive Keratectomy, is approved to treat low to moderate amounts of nearsightedness, farsightedness, and astigmatism by removing tissue from the surface of the cornea. The outcome of PRK is similar to that of LASIK, and most people achieve 20/20 or better vision with PRK. Here at Chicago Cornea Consultants, our surgeons frequently use Mitomycin-C to treat and prevent corneal haze following PRK, so patients can feel confident and at ease with their decision to undergo surgery.
During the PRK procedure at Chicago Cornea Consultants, the patient’s eye is numbed using a topical, or eye drop anesthesia. Then, the surgeon removes the epithelium, a thin layer of protective skin that covers the cornea. This may be done with a blade, a brush, or even the excimer laser, but most commonly is performed with a diluted alcohol solution. During the actual PRK procedure, the patient stares at a fixation light. In less than a minute, the laser removes the precise amount of tissue while it reshapes the surface of the cornea.
Immediately after PRK, a soft contact lens is placed on the eye while the cornea heals. Because the epithelium was removed, patients may experience blurry vision for three to five days after PRK and a moderate amount of discomfort until the epithelium heals and covers the treated area. Various eye drops and oral medications are effective in reducing this post-operative discomfort. Final visual results after PRK may not be fully realized anywhere from several days to a few weeks or more as the surface heals in accordance with each individual’s healing tendencies.
Mitomycin-C
A problem that has plagued PRK in the past has been corneal scarring following PRK for very high amounts of nearsightedness. The surgeons of Chicago Cornea Consultants, Ltd. pioneered the internationally accepted strategy for the treatment and prevention of corneal haze following PRK, utilizing Mitomycin-C (MMC).
Mitomycin-C is an antibiotic chemotherapeutic agent that is used to treat patients who suffer from corneal scarring after PRK. Mitomycin-C can also be used during PRK to prevent corneal haze after the procedure. Mitomycin-C works by inhibiting DNA synthesis, helping to reduce corneal haze after PRK.
Before PRK, the Mitomycin-C is placed in a disposable contact lens vial. A corneal light shield, or sponge, is placed in the Mitomycin-C solution, and after PRK is complete, the sponge is placed on the central cornea and left in place for up to a minute.
Although Mitomycin-C is an effective treatment for corneal haze and scarring, there is no guarantee that haze will not develop after PRK. It is important that you discuss all of your options with us before making a decision. To learn more about MMC, clickhere to read a recent major review of this subject co-authored by Dr. Majmudar and the American Academy of Ophthalmology, or review articles from the bibliographies of Dr. Randy Epstein or Dr. Parag Majmudar.
ISRS/AAO NEWS
AAO is one of the leading international organizations of refractive corneal surgeons, of which we are proud members. Ophthalmic surgeons have been performing refractive surgery for the treatment of myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (irregularly shaped cornea) for approximately 100 years, but the past decades have produced rapid change and growth by means of refined techniques and the emergence of laser vision surgery. In 1978 a refractive procedure called Radial Keratotomy (RK) was introduced in the United States. RK involves making a number of cuts in the cornea to change its shape and correct refractive errors. Following the introduction of RK, eye surgeons routinely corrected nearsightedness, farsightedness, and astigmatism using various applications of incisions on the cornea. In the 1980s a new type of laser called the excimer laser was developed. Though originally used to etch computer chips, ophthalmologists began using the excimer laser successfully in refractive surgery techniques to remove very precise amounts of tissue from the eye’s surface. Excimer lasers revolutionized refractive surgery by providing a degree of safety and precision that was previously unattainable with other techniques. To learn more about the ISRS/AAO, click here.
