Tuesday, August 19, 2008

lasik

LASIK (Laser-Assisted In, Situ Keratomileusis) is one of the surgeries that treats refractive errors of the eye. LASIK is a variant of excimer laser photorefractive keretectomy (PRK). Although LASIK is a newer procedure, it is common as surgical techniques and instruments improve. The primary difference between LASIK and PRK is that prior to the use of the laser to change the shape of the cornea, a machine called microkeretome is used to create a thin flap of cornea, which is folded back, and laser treatment is then performed under this flap. Visually recovery is usually faster as well, because the surface layer of the eye does not need to reheal after being removed as it does in PRK.

LASIK is an exciting surgical procedure that is capable of correcting a wide range of nearsightedness (myopia), farsightedness (hyperopia) and astigmatism. LASIK is the acronym for laser assisted in-situ keratomileusis. The name refers to the use of a laser to reshape the cornea without invading the neighboring cell layers. LASIK is currently the most commonly performed refractive procedure in the United States and in India .

Lasik was first performed in clinical trials in the U.S. in 1991. It was officially approved in 1996 in the U.S. It is important to note that the major components of the procedure have a long history. Ophthalmologists have been reshaping the cornea for over 50 years, creating a protective layer of tissue for over 35 years, and using the excimer laser since the 1980's.

LASIK combines the precision of the excimer laser that is used in PRK surgeries with the flap technique that characterizes ALK. First, no removal of the corneal surface tissue is necessary and therefore, postoperative pain is substantially reduced compared to PRK. Second, postoperative visual acuity is restored within a few days rather than weeks. Finally, there is less corneal scarring in the long-term, less change due to healing (regression) and thus greater stability of the correction.

LASIK improves the uncorrected vision for distance - one's visual capacity while not wearing corrective lenses - in most patients who have the procedure. Nearly all patients can expect to achieve 20/40 vision, which most states consider good enough to drive without having to wear contacts or glasses, and many can expect to achieve 20/20 vision or better. However, there are no guarantees that you will have perfect vision. People who are most satisfied with the results of laser correction clearly understand the potential risks and complications and possess realistic expectations of what their vision will be like after surgery.

The effects of LASIK are permanent. The effects of LASIK do not wear off. But, it is important to realize that a person's eye can still change internally. That is why many surgeons recommend having the procedure done after the major eye changes have occurred in one's life. For instance, LASIK is not recommended on children because their eyes change a great deal. They would need the vision fine-tuned in a few years. If the procedure is performed after the age of 18, the chance of long-term stable correction is more likely. Even the eyes of patients over the age of 18 can still be changing. Therefore, we recommend a good conversation with your surgeon so they can review the changes you have had and help you make a decision whether or not you should wait until the changes have slowed down. Patients should also note that while results are usually stable, they can be modified by enhancement procedures - procedures performed after the initial one - if necessary.

You can resume most normal activities immediately after surgery. However, for at least two weeks you will need to avoid activities that would cause perspiration to run into the eyes. You should wear safety glasses while playing contact sports whether or not you have had surgery. But, if you do not routinely wear safety glasses, your surgeon may recommend wearing them for at least one month after LASIK. You will also need to avoid such activities as contact sports and swimming for several weeks. It is important to talk specifically with your doctor about limitations on activities after LASIK.

Fast visual recovery characterizes this operation. Most patients achieve good vision the day after surgery and find that their eyes feel fairly normal within a day. However, vision can continue to improve, and best vision can still take two to three months to occur. Most patients who have LASIK do not wear glasses for their daily activities. However, patients may need to wear reading glasses if they are over the age of 40. This is caused by the normal aging of the eye known as presbyopia. This condition occurs with or without LASIK. Some patients may need a minimal prescription for some activities such as night driving.

Most people in their 40's or older will need reading glasses if their eyes are corrected for distance because the eye's lens loses flexibility as we age. Some patients in this age group select monovision, such as is done with contact lenses. This option allows patients to use one of their eyes for distance and the other to see up close. Although monovision proves to be satisfactory for some patients, many are not comfortable with this arrangement. We will be happy to discuss this with you to meet your individual needs.

We feel it is of extreme importance that you meet the surgeon who performs the procedure prior to making an informed decision on whether to have the surgery. Our surgeons will discuss the risks and benefits of LASIK with you and will try to tell you what you can expect.



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