ADVANCED SURFACE ABLATION (ASA) Treatment in Ambala
ASA - LASER REFRACTIVE SURGERY
Photorefractive keratectomy (PRK) using the VISX laser was the first method of laser vision correction approved by the FDA. Since the approval of PRK, there have been many improvements in the laser and the techniques used for surface laser vision correction. Advanced Surface Ablation uses laser treatment on the surface of the cornea after removing the surface cells (called the epithelium) which then regrow. For the painless procedure of advanced surface laser ablation, a drop of anesthetic is placed upon the eye followed by removal of the surface epithelium (cells) using the laser, alcohol, or scraping gently (or a combination of techniques). The “cold” laser called an Excimer laser then adjusts the focus of the eye to correct vision by changing the front curve on the cornea to be flatter for nearsightedness and steeper for farsightedness. To correct astigmatism, the laser changes the curves on the cornea to make light focus simultaneously on the retina of the back of the eye. This is bloodless with no cutting. The laser pulses correct curvature with an accuracy of one-millionth of an inch. Best uncorrected vision may improve more slowly with advanced surface ablation and there may be more discomfort for the first 48-72 hours than with LASIK. However, most of our patients have no discomfort because diluted topical anesthetic drops are used until the epithelial cells have healed under a bandage soft contact lens which is placed on the cornea at the end of the laser treatment. Usually, the contact lens is removed in the office and the anesthetic drops stopped about 72 hours after treatment.
It is important to realize that haze or clouding of the cornea may occur with any kind of laser treatment and the risk of haze increases for higher degrees of correction. This risk may be higher for advanced surface laser ablation. An antibiotic called mitomycin may be applied topically for a few seconds for patients requiring higher amounts of correction to reduce this risk.
Advantages of Advanced Surface Ablation (ASA)
- Less thinning , leaving a stronger cornea for all patients. This is particularly important for patients with higher degrees of myopia (thus requiring more tissue removal by the laser for vision correction) or patients involved in contact sports, etc.
- No stromal flap complications such as lost, displaced, or buttonholed stromal corneal flaps. Should these problems happen after Advanced Surface Ablation (ASA), the epithelial flap simply regenerates and grows back into place, unlike LASIK.
- No DLK, inflammation or infection that occurs in the interface with LASIK.. Even if infection occurs in Advanced Surface Ablation (ASA), it is much more amenable to treatment directly with antibiotic drops since the infection is not covered by a stromal flap.
- Less dry eye. The deeper cornea stromal nerves are not cut by the femtolaser or microkeratome.
There is no stromal flap with striae as in LASIK which may cause irregular astigmatism with loss of vision. - In ASA there is no stromal cut created by the femtolaser or the microkerotome. Thus no epithelial ingrowth into the interface cut is possible. In fact, we want the epithelium to grow on the surface after ASA and it usually does so very rapidly.
Possibly decreased risk of retina detachment.
