| PRK and Advanced Surface Ablation (ASA) |
| PRK (Photorefractive Keratectomy) was the first procedure performed using the Excimer laser. It corrects vision by reshaping the cornea. ASA is similar to PRK with minor modifications in order to treat more challenging cases such as patients wanting better vision after Radial Keratotomy. The difference between LASIK and PRK is that with LASIK, a corneal flap is created and the laser is applied to the inner tissue of the cornea. With PRK and ASA, the epithelium (or outer skin of the cornea) is removed and a laser is applied to the surface of the cornea. PRK and ASA can be used to correct nearsightedness, farsightedness and astigmatism just like with LASIK. Unlike with LASIK, PRK and ASA are usually performed on one eye at a time, separated by 1-2 weeks.. |
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PRK / ASA |
LASIK |
| To treat nearsightedness, the steep cornea is made flatter by removing tissue from the center of the cornea. This moves the point of focus from in front of the retina to directly on the retina.
To treat farsightedness, the flat cornea is made steeper by removing tissue outside of the central optical zone of the cornea. This moves the point of focus from behind the retina to directly on the retina. To treat astigmatism, the cornea is made more spherical -- like a basketball instead of a football. This eliminates multiple focusing points within the eye and creates one point of focus on the retina. Astigmatism can be treated at the same time as nearsightedness and farsightedness. |
| PRK is for those who: |
- Want to reduce or eliminate their dependence on glasses or contacts
- Are over 18 years of age
- Have had a stable eye prescription for at least one year
- Have no health issues affecting their eyes
- Have corneas too thin for LASIK
- Vision has worsened years after Radial Keratotomy
- Vision is not clear after Corneal Transplantation
- Want better natural vision after cataract surgery or refractive lens exchange
What to expect on surgery day & recovery: |
 Once you will arrive at the Alabama Vision Center, you have been checked in and offered additional sedative to help you relax. You will then be prepared for surgery. The area around your eyes will be cleaned and a sterile drape may be applied around your eye. Anesthetic eye drops will be used to numb your eyes; no injections or needles will be used. When your eye is completely numb, an eyelid relaxer will be placed between your eyelids to keep you from blinking during the procedure. |
| Next, Dr. Kloess or Velazquez will remove the epithelium, the thin outer layer of protective tissue that covers the cornea. You will be asked to look directly at a target light while the laser reshapes your cornea. The laser will be programmed with the information gathered in your pre-operative exam. A contact lens will be given for comfort and left in place for 3-5 days until the corneal surface heals. The entire process will be completed in less than a two minutes and is painless. |
| Following your procedure, your eyes will be examined and you will leave the center with protective sunglasses. Your vision may be blurry for several days. You will be prescribed pain medication; however, most patients do not require it since only minor discomfort is experienced. You will take eye drops that will be tapered over a several week schedule. Most patients resume normal activities the next day. You will follow-up in 3-5 days to access healing and have the contact lens removed. Vision improves remarkable by the 7-10th day and can fluctuate for several months |
If you want to restore your natural vision and have been told you are not a LASIK candidate, contact us today to schedule a free consultation for PRK/ASA!