What is PRK? (P)hoto(R)efractive (K)eratectomy

PRK consists of excising a thin layer of corneal tissue from the top of the cornea with the excimer laser. The procedure requires re-growth of the epithelium and it destroys a portion of the Bowman's membrane. This creates a longer healing period and, for many, significant discomfort.  Additionally, many patients experience a haze beneath the surface which, in some patients, can cause significant interference with visual acuity. This may require additional medications and frequent follow-up exams over a fairly long period of time.

The essential steps involved in PRK are:

• Gently removing the surface layer of epithelial cells.

• Ablating (or removing by molecular disruption) the corneal tissue to change its shape.  A crucial point here is that this involves going through the layer of the cornea immediately below the epithelium, called the Bowman's membrane. This does not grow back and the long term significance, if any, of its not being there is not fully known.

• Healing requires usually two to four days for the surface epithelium to grow back across the 6 to 7 millimeter area over which it was removed. During this time there can be very significant discomfort, although the use of certain drops and a type of soft contact lens as a "bandage" may help considerably. The continued healing and apparent attempt of this surface epithelium to "replace its original shape" can lead to a period of up to 3 to 12 months for maximum stability and visual acuity to occur, although most people see quite well within a few weeks.

Perhaps the most significant issue with PRK is that in many patients, probably related to the necessity for re-growth of the epithelium and the absence of the Bowman's Membrane, there is some degree of haze that develops in the area beneath the surface.  In most patients, this has no appreciable affect on vision, but it can create an interference with visual acuity in some people - increasing in frequency the higher the range of myopia being corrected. Attempts to prevent or control this haze can involve the use of cortisone type eye drops and frequent follow-up exams, sometimes over a fairly long period of time.  In some people, the long term use of these cortisone type drops can cause a type of glaucoma or even cataract.

What to expect on the day of your procedure

The following is a general idea as to what you should expect on your procedure day.

 UPON ARRIVAL

• Please be sure to bring your already signed/initialed Informed Consent booklet.
• When you arrive, please enter the elevator on the ground floor and press “2R”.  This will bring you to the VisionaryUSA.com Surgery Institute floor, and please turn to the right as you exit the elevator.  Then, enter through the LASER CENTER door and sign in.  Have a seat in the waiting area and we will be right with you.
• The procedure process will not take long, so it is recommended that the person accompanying you stay with you during your visit if possible.
• You will be given Valium to help you relax.  (If you are allergic to Valium or similar medications, please notify us before your surgery day so an alternative may be arranged.)
• Some further testing may be performed on your eyes, particularly a test called WaveScan®.  WaveScan® is a highly technical test that measures your eyes 25-times more precisely than standard methods used for eyeglass and contact lenses.  The information collected is then transferred to the laser, providing a new level of precision and accuracy. 

 THE PROCEDURE

• The procedure takes approximately five (5) minutes per eye.
• The laser staff team will prepare you for the procedure by explaining how to focus on the laser and what sensations you may expect during the procedure.
• Eye drops will be used to numb your eye, and your eye area will be cleaned.
• Your laser staff team will communicate with you about each step, talking you through the procedure.  In this regard, there are no surprises and you will feel more comfortable.
• There is no pain at all.  The only thing you feel is your surgeon’s gentle touch and mild pressure.
• Tape may be used to place your eyelashes off to the side.
• A small speculum keeps your eyes from blinking.
• The laser makes a loud clicking noise.
• You can sometimes smell the evaporation of tissue.
• You may feel the sensation of cool water on your eye.
• You don’t have to worry about blinking or moving your eyes.  The laser has a sophisticated tracking system that follows your eyes.  Should you move even more than a millimeter, the laser shuts itself off automatically.
• After the surgeon has completed your surgery, a protective clear eye shield will be placed over your eyes.

AFTER THE PROCEDURE

• You will be assisted to the recovery room where you will relax in a comfortable recliner in a dim room while you adjust to your new vision.   
• After approximately thirty (30) minutes, the surgeon will check the health of your eyes.
• You will be given an eye kit and instructed on how to use the items given to you.
• You will be scheduled to return the following day for a one-day follow-up appointment. 
• You will then be released wearing your protective eye shield or sunglasses. (See post-operative instructions.)

Further Information

:: Pre-Operative Instructions
:: Post-Operative Instructions