ASLA Laser Eye Surgery – ASLA Correction / PRK
Prior to the development of LASIK, Advanced Surface Laser Ablation, or ASLA, was the first excimer laser procedure.
ASLA involves applying the laser beam directly onto the surface of the cornea once the outer layer, the epithelium, has been removed, rather than under a corneal flap as in LASIK.
It may be associated with some discomfort and longer visual recovery than LASIK but it causes less thinning of the cornea and is occasionally preferable to LASIK in lower degrees of refractive error.
PRK
Photo-refractive keratectomy, also known as PRK, is a procedure that corrects vision by reshaping the cornea. With PRK, the corneal epithelium is removed and discarded, allowing the cells to regenerate after the surgery. This procedure can be used to correct shortsightedness, farsightedness and astigmatism.
PRK (Photo refractive keratectomy) is a procedure whereby the front surface of the cornea is reshaped to correct your refractive error. The process is also called Excimer Laser “Photo Ablation” or laser surface ablation. The process precisely removes tissue from the front surface of the cornea without damaging surrounding tissue.
This procedure is commonly used to reduce the chance of complications that can occur when a flap is created as with LASIK or when the cornea is too thin to cut a flap.
On the day of the surgery the surgeon carefully removes the corneal epithelium. The Excimer Laser ablates the underlying layers during the PRK procedure to alter the cornea to the required shape.
When the treatment is complete a “bandage” contact lens is put on the treated eye. The contact lens will remain in place for 3-4 days to allow greater post-operative comfort until the epithelial layer has regenerated.
Instructions will then be provided on the use and dosage of your drops. A clear shield will be placed on the eye. You may remove the shields in the morning of your first post operative check.
You will be required to return the following morning for a post-operative check where the surgeon will remove the eye shield and examine the cornea.
Epi-LASIK
Epi-LASIK is an abbreviation for Epithelial Laser In-Situ Keratomileusis. This procedure is an advanced type of corneal surface ablation to correct shortsightedness, farsightedness and astigmatism. In this procedure, a specially designed microkeratome like instrument is used to create a thin flap of corneal epithelium. This procedure can be used for patients who have thin corneas and might not otherwise be good candidates for ordinary LASIK.
LASEK
LASEK (laser epithelial keratomileusis) is a variation of PRK. It is also called E-LASIK or epithelial LASIK. Once again this procedure is used to reduce the chance of complications that can occur with a flap or when the cornea is too thin.
LASEK procedure attempts to preserve the epithelium (outer layer of the eye) unlike PRK where the epithelial layer is completely removed.
A fine surgical instrument is used to outline the epithelial layer of the cornea while a diluted solution of alcohol is applied for 45 seconds to loosen the epithelial layer. The eye is then irrigated with saline to remove all traces of the alcohol. The surgeon will then gently fold back the epithelial flap and use the Excimer laser to reshape the cornea as with LASIK or PRK. Once the laser treatment is complete the epithelial flap is replaced back onto the eye.
When the treatment is completed a “bandage” contact lens is put on the treated eye. The contact lens will remain in place for 3-4 days to allow greater post-operative comfort until the epithelial layer has regenerated.
Instructions will then be provided on the use and dosage of your drops. A clear shield will be placed on the eye. You may remove the shields in the morning of your first post operative check.
You will be required to return the following morning for a post-operative check where the surgeon will remove the eye shield and examine the cornea.
