Fahmi Rizwansyah says:
LASIK surgery is one type of refractive surgery. Refractive surgery can eliminate the need for eyeglasses or contact lenses in people with these conditions:
* Nearsightedness
* Farsightedness
* Astigmatism (unevenly curved cornea)
* Presbyopia (age-related loss of sharp close-up focusing)
Done on both eyes, these procedures work by changing the eyes' focus to improve vision.
You might assume that refractive surgery is fairly new. But it goes back about 100 years! You're right, however, to think that today's state-of-the-art refractive surgery procedures are of more recent development. These newer techniques were first performed in the U.S. in 1978.
Types of Refractive Surgery
Three types of refractive surgery procedures are available. They include:
* Excimer laser procedures (including LASIK surgery)
* Artificial lens implantation
* Cornea reshaping procedures (including radial keratotomy, the first-used refractive surgery)
The Excimer Laser Used in LASIK Surgery
Developed in the 1980s, the excimer laser is computer-controlled.It gives eye surgeons the ability to remove precise amounts of tissue from the surface of the eye. This provides a high degree of safety and precision for laser-assisted procedures like LASIK.
LASIK Surgery Steps
LASIK is an abbreviation for "laser-assisted in situ keratomileusis." The steps of LASIK surgery include:
1. Eye numbing drops are given before surgery to prevent pain.
2. The eye surgeon creates a flap in the cornea. The surgeon may use either an instrument called a microkeratome or a femtosecond laser. The flap is folded back to reveal the cornea's midsection (stroma).
3. The excimer laser vaporizes part of the stroma.
4. The corneal flap is put back in place. It reattaches within a few minutes without sutures.
5. Eye drops or ointment is applied to aid healing.
Recovery from LASIK surgery is usually fast and painless.You may notice improved vision by the next day or sooner.
Procedures Related to LASIK Surgery
Doctors have developed other surgeries similar to the standard LASIK procedure. These include the following.
* Epi-LASIK uses a special instrument, the Epi-keratome, to create the corneal flap on the layer of cells covering the cornea (epithelium). Epi-LASIK is used in patients with corneas too thin to allow the standard LASIK surgery.
* Wavefront-guided LASIK creates a highly detailed "map" of how light moves through the eye. This shows even the subtlest distortions of focus. The goal is to reduce the chance of after-surgery problems such as glare, light "halos," and poor night vision.
* PRK (photorefractive keratectomy) corrects low to high nearsightedness, low to moderate farsightedness, and astigmatism. The eye surgeon removes the epithelium. Then the surgeon uses the excimer laser to reshape the cornea. Healing occurs with help from a "bandage contact lens" applied at the end of the procedure. Healing takes three to four days and may involve some discomfort. Full recovery may take several weeks. For these reasons, LASIK surgery has generally replaced PRK except for patients with corneas too thin for LASIK surgery.
* LASEK (later epithelial keratomileusis) is similar to PRK. The difference is that the surgeon replaces the epithelium after completing the surgery. LASEK may be recommended for people with thin corneas. As with PRK, healing may involve some discomfort.
Implant Refractive Surgery
Several types of refractive surgery rely on implants to help improve vision. These procedures include the following:
* Intrastromal corneal ring segment (INTACS) implants
* Phakic intraocular lenses (IOLs)
* Accommodative IOLs, multifocal IOLs, and refractive lens exchange
Each implant is described below.
* Intrastromal corneal ring segment (INTACS) implants. Semicircular pieces of plastic are implanted in the cornea. These objects are called INTACS (intrastromal corneal ring segments). They change the cornea's shape and adjust the person's power to focus. INTACS are inserted through a small corneal incision. The incision is closed with two small sutures, or stitches, typically removed two to four weeks later. If necessary, INTACS can be removed. The cornea returns to its original shape within a few weeks.
* Phakic IOLs. These areused for people whose degree of nearsightedness or farsightedness is too high for safe use of the excimer laser. The procedure is similar to cataract surgery except that the natural lens is not removed. The eye surgeon positions a vision-correcting plastic lens in front of the patient's natural lens, which is left in place to preserve reading vision. Because the eye is actually entered, phakic IOL surgery carries a higher risk of complications.
* Accommodative IOLs, multifocal IOLs, and refractive lens exchange. These implants areused to treat nearsightedness, farsightedness, and presbyopia. Vision-correcting, surgically implanted artificial lenses replace natural lenses. No corneal reshaping is done.
Surgery to Reshape the Cornea
Two surgical procedures are used to change the shape of the cornea, achieving vision correction. These procedures include the following:
* Conductive keratoplasty (CK) uses heat to reshape the cornea. The heat source may be a type of laser (not the excimer laser used in LASIK surgery). The heat is applied to the cornea's outer edge so it tightens and makes the cornea steeper. This can be used to correct farsightedness, presbyopia, and near-focus problems in people over age 40. CK causes little or no discomfort. It improves vision almost instantly. This effect may not last, however. Later re-treatment may be required.
* Radial keratotomy (RK) is the first form of refractive surgery used in the U.S. It has been largely replaced by LASIK surgery. RK may be chosen to correct very mild nearsightedness and astigmatism. The eye surgeon uses a diamond scalpel to make spoke-like (radial) cuts on the cornea. These cuts flatten and reshape the cornea. RK weakens the eye's structure, a primary reason it is seldom done now.
Who Can - and Cannot -- Have LASIK Surgery or Other Refractive Procedures?
Everyone considering refractive surgery should make the decision only after meeting with a refractive surgeon. General requirements include:
* Being age 18 or older
* Having healthy eyes
* Not needing a new eyeglass or contact lens prescription over the past year
* Having vision that refractive surgery can correct
Most forms of refractive surgery cannot be done on people who:
* Have a history of eye disease, including autoimmune disease, or previous eye injury
* Take certain prescription medications known to affect vision or corneal healing
* Are pregnant or nursing
Ask your surgeon about the risks of surgery as well as the benefits. That way, you can make a more informed decision. The outcome will be more likely to meet your expectations.
The Cost of LASIK Surgery
Most types of health insurance will not pay for refractive surgery. Only about 3% of LASIK surgery procedures cost less than $1000 per eye. The good news is that the cost seems to be coming down.
On average nationally in mid-2006, the cost of having LASIK surgery done on both eyes was $1950. Using wavefront technology or the "laser microkeratome" costs more. Price also varies slightly by region.
Be sure your surgeon makes clear what is and is not included in the price you are quoted. Ask, too, if you will have to pay more if you need follow-up visits or treatment for complications.
by webMD
Cheers, frizzy2008.