Although PRK can be offered to most nearsighted and farsighted individuals there are some important guidelines. PRK is available to patients who are at least 21 years old and whose eye glass prescription has stopped changing. Mild to severe nearsightedness in the range of -1.00 to -12.00 diopters with up to 4 diopters of astigmatism can be treated. Also farsightedness between +1.00 and +6.00 diopters with less than 1 diopter of astigmatism may be corrected.

Your eyes should generally be healthy although eyes with certain minimal problems may still be eligible. It is important to tell your doctor about any eye conditions or general health problems and about any medications you use. In some situations, PRK should not be done. Individuals with vascular disease, autoimmune disease (rheumatoid arthritis, lupus), immunodeficiency or corneal deformity (keratoconus) are not candidates. Women must avoid PRK during pregnancy and nursing. Patients who form excessive scar tissue (keloids) or have had herpes virus infections of the eye are not PRK candidates. Patients are not eligible for PRK while on certain medications including Accutaine, steroids, Cordorone or Imitrex.

Instructions for Photorefractive Keratectomy (PRK)

Date of Procedure: __________________

Date of 1st Post-Operative Visit: _____________________

Time of Procedure: __________________

Time of 1st Post-Operative Visit: _____________________

Your procedure will take place at the Manhattan Eye, Ear & Throat Hospital located at 210 East 64th Street (between 2nd and 3rd Avenue) at the above date and time. Please go directly to the seventh floor (laser and retinal department) and check-in 45 minutes before your procedure.

On the day of the procedure you may eat but a light meal is recommended. Please be sure to wear comfortable clothing. Please do not wear any cologne, perfume, earrings, necklaces or eye makeup. Your eye will be numbed with drops alone (no injection) and you may be given a mild sedative by mouth. Afterwards, a clear bandage contact lens will be placed to protect the eye while the epithelium heals. You will see with the treated eye but the vision will be somewhat blurry at first. You will likely experience some burning, tearing and light sensitivity and a foreign body sensation in the eye. You will receive a prescription for pain medication which may be used should the eye become uncomfortable. Prescriptions for eye drops will also be given. If possible, please bring a companion to help you home after the procedure.

Immediately after the procedure you should take your eye drops. One drop of gatifloxacin (an antibiotic) and FML (a mild steroid/anti-inflammatory) should each be used every four hours spaced at least 5 minutes apart. Artificial tears or contact lens re-wetting drops may also be used as needed to relieve any dryness or sticking sensation. Typically the gatifloxacin may be stopped 3 to 4 days after the epithelium has healed. The FML will be slowly tapered off over a period of weeks. Do not discontinue any drops unless specifically instructed to due so. You should avoid swimming and strenuous exercise for about one week following the procedure. It is advisable to stay home from work on the first day following the PRK; in most cases it will be possible to return to normal activities including work by the second day.

Excimer Laser PRK is an elective procedure, the alternative being glasses, contact lenses or other refractive surgical procedures such as  LASIK.

The excimer laser produces an invisible ultraviolet light that was originally developed etch computer microchips. This laser light was subsequently found to be uniquely suited for corneal reshaping. Each pulse of the laser removes a microscopic shaving of corneal tissue. The excimer is said to be “cool” because unlike other types of lasers it does not produce heat that could damage delicate eye structures.

A computer precisely controls the pattern and number of pulses applied, sculpting the cornea into shape. This reshaping of cornea changes its focusing power so that images are sharply focused on the retina.

Pre-Treatment Evaluation

An initial screening eye exam is required to determine if you are a candidate for laser vision correction. Your prescription needs to be stable for at least one year. Old glasses or prior eyeglass prescriptions can establish this. Contact lens may alter an individual’s prescription and must be removed prior to the exam (three weeks for gas permeable lenses and one week for soft lenses). Candidates will then have a comprehensive eye examination to determine the exact treatment plan. This will include a computerized mapping of the corneal surface.

Excimer Treatment

Excimer Laser Treatment

Treatments are performed on an out patient basis. You will need to bring a companion to assist you in your return home. Drops to numb the eyes will be administered and you may be given a mild sedative by mouth. Your prescription will be programmed into the computer, which directs the laser to deliver the correct pattern of pulses.

The surgeon aligns the eye under the laser’s microscope and removes the epithelium (the protective outer “skin” of the cornea).

The laser than sculpts the cornea to its new shape in a process typically requiring 30 to 45 seconds. Antibiotic drops will be placed on the eye. In most cases a clear bandage contact lens will be placed to protect the eye while the epithelium heals. Occasionally, however a patch will be required.

Eye Following Excimer Laser Correction of Myopia

Some discomfort or foreign body sensation is expected in the first 24 to 36 hours along with light sensitivity and tearing. Most individuals can return to work on the second day following the PRK. Prescription pain medications may be used as needed.

Post Treatment

The epithelium (surface layer) heals in about 2-3 days for nearsightedness and 3-5 days for farsightedness. Vision may be somewhat blurry for the first several days but clears significantly by three to six days and 90% of the vision correction has taken place by this time. The remaining healing “fine tunes” the result slowly over the next several months. Appropriate follow-up care is important. Dr. Haight will outline the schedule of visits and medications to be used. These steps should be followed carefully as proper healing is critical to achieving the desired effect.

After analyzing the results of the PRK performed during investigational studies in the US and Canada, the US Food and Drug Administration has approved laser vision correction of low to high degrees of myopia and hyperopia. More than 90% of patients achieve vision of at least 20/40 allowing them to drive legally without glasses or contacts.

Unwanted effects of the PRK can occur. Some individuals will be over corrected or under corrected. Over correction of myopia, causes farsightedness which may be more of a problem in older patients and could cause some individuals to need reading glasses, distance correction or both. Over correction of hyperopia produces nearsightedness, which causes distance vision to be blurry but still permits or even facilitates close vision. Under correction of myopia means some nearsightedness remains. A weak lens prescription may be needed to optimize vision. Under correction of hyperopia leads to a residual fardightedness – again a weak prescription may be helpful.

Individuals with significant over or under correction may be candidates for retreatment.

Rarely patients develop haziness of the cornea severe enough to cause glare, halos around lights or reduction in vision. Such cases may be treatable with eye drops or repeat PRK.

Severe infections are rare but can occur. They are usually treated successfully with antibiotic drops.

In the first few days following the treatment swimming and strenuous exercise should be avoided. Dr. Haight and colleagues at Manhattan Eye & Ear has shown that the strength of the eye is not weakened by the laser. Therefore, usual sports activities may be resumed. Of course, some sports or occupational activities require the use of protective eye wear and these practices should continue after the laser procedure.

Yes. A contact lens may be worn during and after the time of treatment.

In most cases, both eyes are treated at the same time. In rare instances, only one eye requires treatment. For patients who are already presbyopic ( need reading glasses for close work) the target correction may be different for the two eyes. This technique is referred to as monovision, and creates a full distance correction for the dominant eye, and a nearsighted correction for the non dominant reading eye.

By the early 40’s almost everybody needs extra help for close-up focusing. PRK will not correct this problem so you will need to use simple reading glasses. Individuals who experience an over correction from PRK for myopia will need reading glasses at an earlier age. Some nearsighted people in their 40’s discover that they can read by simply removing their glasses. After PRK restores clearer distance vision, this will no longer be an option and reading glasses will be needed. Monovision may also be an option. With this technique, the dominat eye receives a full distance correction, while the non dominant eye receives a near sighted correction to facilitate reading.

We want you to have complete understanding of the risks, benefits and alternatives to PRK. This description can give only part of the story. You are encouraged to discuss these issues with Dr. Haight so that you can make a truly informed discussion.