Vision Correction Options

Types of Laser Vision Corrections:

 

LASIK (laser in-situ keratomileusis)
SBK (Sub-Bowman's Keratomileusis)
PRK (Photo-Refractive Keratectomy)
LASEK (Laser Epithelial Keratomileusis) or Advanced Surface Ablation (ASA)
Intacs (Corneal Ring Segments)
Intacs for Keratoconus

LASIK (laser in-situ keratomileusis)
LASIK is one of the most popular vision correction procedures used today. With this procedure, vision is corrected by reshaping the corneal tissue beneath the surface of the eye. A "flap" is created on the corneal surface, which is then flipped back while the surgeon uses a laser to treat, or reshape, the deeper layers of the cornea. The flap is then folded back in place where it bonds without the need for stitches.

The benefits of LASIK, because it is performed under a protective layer of tissue, are that there is less surface area to heal, less risk of corneal haze, less postoperative discomfort, and less need for postoperative medication than with some other procedures. Vision returns rapidly, often within a day or two. 

SBK (Sub-Bowman's Keratomileusis)
SBK is an advanced vision correction procedure. It is similar to LASIK in that a flap is created and the laser treatment is performed underneath this protective layer of tissue. However, the flap for SBK is not nearly as deep as it is for LASIK. The flap is produced just below the Bowman's membrane of the cornea in SBK. This method retains the original thickness of the cornea and reduces the risk of ectasia, a potential complication of LASIK which leads to a thin and bulging cornea.

The benefits of SBK over traditional LASIK include offering a more immediate improvement in vision, decreased treatment time, maintained and possibly increased corneal strength, increased accuracy, and reduced risk of complications.   More information on LASIK and SBK can be found here.

PRK (Photo-Refractive Keratectomy)
PRK is another laser vision correction procedure that corrects vision by reshaping the cornea. The difference between PRK and LASIK is in where the laser treatment takes place in the cornea. With LASIK, a flap is created on the surface of the cornea, which is then folded back while the laser treatment is applied to the inner tissue. With PRK, no flap is created. The outer layer of the cornea, or epithelium, is removed and a laser is applied to the surface of the cornea. Because the epilthelium is removed, a contact bandage is placed over the eye during the healing phase. The epilthelium grows back very quickly, but you may experience some discomfort, especially during the first few days. Most patients resume normal activities within one to three days.  More information on PRK can be found here. 

LASEK (Laser Epithelial Keratomileusis) or Advanced Surface Ablation (ASA)
LASEK is a procedure that combines some aspects of PRK and LASIK. It is similar to PRK because it is performed on the cornea's surface. However, instead of removing the epithelium (the thin layer of protective skin that covers the cornea) as in PRK, a flap of surface epithelium is loosened with a diluted alcohol solution and moved aside. This creation of a flap is similar to the LASIK procedure, except the flap for LASEK is created on the very outer surface of the cornea. Once the flap is moved aside, the surgeon uses a laser to treat the surface underneath the epithelium. The epithelial flap is then returned to its original position.

LASEK can be used to treat nearsightedness, farsightedness, and astigmatism, using the same principles as with PRK and LASIK:
To treat nearsightedness, the steep cornea is made flatter by removing tissue from the central part of the cornea. This flatter cornea results in moving the point of focus from in front of the retina to directly on the retina.  More information on LASEK can be found here. 

Intacs (Corneal Ring Segments)
Intacs are an alternative to laser vision correction procedures. They are used to treat low levels of nearsightedness and astigmatism, but they do not involve the use of a laser to change the shape of the cornea as many other procedures do.

Intacs are clear, micro-thin prescription ring segments that are made of biomedical plastic. They are surgically inserted into the outer portion of the cornea and act to flatten the central part of the cornea.

Unlike laser vision correction procedures, where corneal tissue is actually removed, no tissue is permanently removed with Intacs. If you are not satisfied with your vision after the placement of Intacs, they may be removed and even replaced with a different prescription.

Intacs for Keratoconus
Keratoconus is a corneal disease that involves progressive thinning of the corneal stroma. It frequently affects both eyes, often with one eye being more involved than the other. As the disease progresses and the cornea grows thinner, it begins to bulge forward in shape of a cone, resulting in distorted and blurry vision. It often becomes difficult to properly fit these patients with contact lenses or to correct their vision with eyeglasses. For many patients with keratoconus, the only method previously available to restore functional vision was a corneal transplant.

INTACS may provide another alternative to this subset of patients. INTACS are clear, micro-thin prescription ring segments that are made of biomedical plastic. They are surgically inserted into the outer portion of the cornea and act to flatten the central part of the cornea.  More information on Intacs can be found here.

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Last modified: May 31, 2013
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