ASA (advanced surface ablation) also known as PRK (photorefractive keratectomy) was the most popular refractive procedure before LASIK entered the medical industry as a more patient friendly alternative.
Both ASA and LASIK are considered "laser eye surgery," but each varies slightly when it comes to pros and cons. LASIK patients experience very little discomfort and achieve good vision more rapidly — ASA however takes days or sometimes weeks. Many doctors recommend ASA in certain situations such as when a patient has thin corneas.
ASA was developed in the early 1980s. The 1st FDA approval for ASA was in 1995, but the procedure existed in other countries for years. You may recall, a large number of US citizens had ASA in Canada prior to it being available in the States.
ASA is accomplished with an Excimer laser, which uses a cool UV beam to specifically remove (or "ablate") minuscule bits of tissue from the cornea to reshape it. When you change the shape of the cornea, it more accurately focuses light into the eye and onto the retina providing more precise vision.
Patients who are nearsighted, farsighted, or have astigmatism can benefit from ASA. When nearsighted, the surgeon aims to flatten the steep cornea; when farsighted, a steeper cornea is preferred. Astigmatism is corrected by smoothing an uneven cornea into a more regular shape.
ASA is a fast procedure; you walk into the laser center, have ASA and walk out again. In fact, the actual surgery usually takes only a few minutes, and you are awake the whole time. Occasionally, the doctor will give you a oral sedative such as Valium before the surgery.
Most patients do not experience pain during ASA. Your eyes are anesthetized with special eye drops prior to the procedure. The higher your prescription, the more time the surgery will take. But even for high prescriptions, the laser treatment only takes minutes.
After the procedure, you will want to relax and rest for a little while and take a nap at home.
After ASA Surgery
As with any kind of surgery it's paramount that you follow your post op instructions to the letter. Get proper rest, use all prescribed drops as directed and call the doctor if you have a concern.
Immediately after ASA, the doctor will have you rest, then your driver can take you home. Once you are home, you should take it easy for the next few days and plan to have your driver bring you back for your 1 day post op appointment. You will wear a special contact lens that acts as a “bandage”, use antibiotic drops and anti-inflammatory drops. Your surgeon also will prescribe medication to reduce eye discomfort that you are likely to experience the first few days after ASA surgery.
ASA and LASIK outcomes are similar. Most patients achieve 20/20 or better with ASA and LASIK. Some may achieve only 20/40, which is still good vision and is considered good enough for driving by most DMVs. Some patients still may need glasses or contact lenses following the procedure, though their prescription will be much less than it was initially.