PRK: Photorefractive Keratectomy Procedure

PRK also known as AST (Advanced Surface Treatment) or ASA (Advanced Surface Ablation) has demonstrated over a long period of time to be safe, effective, and a predictable method of Laser Vision Correction. 

The PRK procedure is similar to that of LASIK in the way that the laser is applied to the eye.  The main difference is that there is no flap creation.  Instead, the laser is used to produce your optical correction by reshaping the outermost surface of the cornea, rather than the tissue beneath a flap, as in LASIK.  This requires the removal of a thin layer of corneal epithelium, which may produce varying degrees of temporary discomfort for up to a few days after your treatment.  In general, PRK provides a slower visual recovery than LASIK.  It typically takes 1-2 weeks or longer for patients to achieve their best vision.

Dr. Bogart prescribes additional medications and places a thin, soft bandage contact lens over the eye to protect the eye and minimize discomfort for the first few days after treatment as the cornea heals.  Surface Ablation is recommended for those patients:

• whose prescription is too high to have LASIK safely
• whose corneas are too thin to have LASIK safely
• whose corneas display evidence of scarring from infection or trauma
• who have had a previous LASIK procedure over 5 years ago
• who live an active lifestyle, military personnel, police officers, firefighters, athletes, kick-boxers, martial artists, or those who are in or around dust environments, chemicals, or smoke on a regular basis.
• whose primary goal is SAFETY, PRK is the safest procedure for anyone considering refractive surgery.

Surface Ablation is an ambulatory procedure; you walk into the surgery center, have surgery, and walk out again.  In fact, the actual surgery usually takes less than a minute, and you’re awake the whole time.  Dr. Bogart will have you take a mild oral sedative beforehand.  For the Surface Ablation procedure, no scalpels are used and no incisions are made.  Prior to the procedure, Dr. Bogart will put a few anesthetic drops in to numb the eye and prevent pain.

 

Most people don’t feel pain during the Surface Ablation procedure.  Your eyes are first anesthetized with special drops.  Dr. Bogart will have you lie down, to make sure your eye is positioned directly under the laser.  (One eye is operated on at a time.)  A kind of retainer is placed over your eye to keep your eyelids open.  Normally, this is not uncomfortable.  It has a suction ring that keeps your eye pressurized and immobile.  The pressure feels awkward, but does not hurt.

Dr. Bogart prepares the eye by gently removing the eye’s protective first layer of cells, or epithelium (this will naturally regenerate itself in a few days), to reveal the next layer of corneal tissue known as Bowman’s layer.  He will then smooth the area and proceed with applying computer-controlled pulses of cool laser light to precisely and delicately reshape the curvature of the eye.  Deeper cell layers remain virtually untouched. 

The whole Surface Ablation treatment itself is usually completed in less than five minutes and is painless.  Since a layer about as slender as a human hair is typically removed, the cornea maintains its original strength.

Post-operatively, Surface Ablation patients are placed on antibiotic drops, along with anti-inflammatory agents to promote comfort and reduce swelling.  Patients are also fitted with a bandage contact lens to improve their comfort while their eye is healing.  Once the epithelium has healed, usually on the third or fourth post-operative day, Dr. Bogart will remove the contact lens bandage.  Sometimes, daily eye examinations are required.

Immediately after your procedure, Dr. Bogart will have you rest for a bit, then you can go home (someone else must drive).  At home, you should try to sleep for at least the first 4 hours, or longer.  You may be able to go to work the next day, but many doctors advise a couple of days rest instead.  They also recommend no strenuous exercise for up to a week, since this can traumatize the eye and affect healing. 

 

Avoid rubbing your eyes.  In addition to anti-inflammatory agents, you will use antibiotic and steroid drops for a week following the surgery.  Although Surface Ablation has less dry eye discomfort following surgery, you will still be encouraged to use over-the-counter artificial tears for several weeks.

Most people achieve 20/20 or better vision with Surface Ablation (also true of LASIK).  Some may achieve only 20/40 or not quite as good.  In fact, 20/40 is fairly good vision.  In most states, it is good enough for driving.  Some patients may still need glasses or contact lens following laser vision correction, though their prescription level will be much lower than before. 

Postoperative complications can include infection and/or night glare (starbursts or halos that are most noticeable when you’re viewing lights at night, such as while you’re driving). 

Even if you see perfectly after laser eye surgery, you may still need reading glasses or bifocal contact lenses once you hit your 40s.  This is because the eye’s lens stiffens as you age, a condition called Presbyopia.  Your distance vision will probably remain crisp, but seeing up close will be more difficult unless you are already over the age of 40 and have Mono Vision. 

 

 

The History of PRK

 

It may be hard to believe these days, when everything is “LASIK this” and “LASIK that,” but PRK (Photo Refractive Keractectomy) used to be the most common refractive surgery procedure.  Both are grouped under the umbrella, “laser eye surgery.”  Each is a little different when it comes to advantages and disadvantages.  LASIK patients have less discomfort and obtain good vision more quickly (with PRK improvement is gradual and over a few days, or even months).  Many surgeons prefer PRK for patients with higher prescriptions, larger pupils, or thin corneas. 

 

PRK was invented in the early ‘80s.  The first FDA approval of a laser for PRK was in 1995.  The PRK procedure was practiced in other countries for years.  In fact, many Americans had the surgery done in Canada before it was available in the U.S.

 

PRK is performed with an excimer laser, which uses cool ultraviolet light beams to precisely remove (“ablate”) very tiny bits of tissue from the surface of the cornea in order to reshape it.  When you reshape the cornea in the right way, it works better to focus light into the eye and onto the retina, providing clearer vision than before. 

 

Both nearsighted and farsighted people can benefit from PRK.  With nearsighted people, the goal is to flatten the too-steep cornea; with farsighted people, a steeper cornea is desired.  Also, excimer lasers can correct astigmatism, by smoothing an irregular cornea in to a more normal shape.

 

IF YOU WOULD LIKE TO SCHEDULE AN APPOINTMENT TO SEE IF PRK IS THE BEST PROCEDURE FOR YOU, GIVE US A CALL:  803-794-0000