LASIK eye surgery: Alternative to corrective lenses

LASIK eye surgery — short for laser-assisted in-situ keratomileusis — has resulted in making clear vision a reality for millions of people who used to rely on glasses or contact lenses. With increasing experience and advances in technology, outcomes and predictability of LASIK eye surgery have greatly improved in recent years. But complications associated with LASIK eye surgery still exist. Before you schedule LASIK eye surgery, find out what it entails and what could go wrong.

How does LASIK eye surgery work?
LASIK eye surgery changes the shape of your cornea — the transparent membrane that arcs over your pupil and the colored part of your eye (iris). After the procedure, your cornea should bend (refract) light rays to focus more precisely on your retina rather than at some point beyond or short of your retina.

LASIK eye surgery may be an option for you if you have nearsightedness (myopia), farsightedness (hyperopia) or astigmatism.

What might disqualify you from having LASIK eye surgery?
LASIK eye surgery poses particular risks for some people. You should definitely not have this surgery if you have

* Immune system disease

* Persistent dry eyes

* Eye characteristics like an extremely uneven corneal surface or an otherwise abnormally shaped cornea

* Fluctuating or progressively worsening of the quality of your vision etc.

Can someone with presbyopia get LASIK eye surgery?
Certain people with presbyopia may benefit from LASIK eye surgery, although there are limitations. Most people in their 40s have some signs of presbyopia — a refractive error that develops as you age — such as difficulty reading or performing other close-up tasks. The condition is usually well managed with the use of reading glasses.

If you have presbyopia, LASIK eye surgery may give you clear distance vision, but it might make it even more difficult for you to see objects close up. To avoid this, you might choose to have your vision corrected for monovision. With monovision, one eye is corrected for distant vision and the other for near vision. Not everyone is able to adjust to or tolerate monovision, so it’s wise to undergo a trial with contact lenses before opting for a permanent surgical procedure.

How do you prepare for LASIK eye surgery?
Before surgery, your eye doctor takes a detailed medical history and uses specialised equipment to carefully measure your cornea, noting the shape and any irregularities.

If you wear contact lenses, you will need to switch to glasses full time a few weeks before this exam. Contact lenses can distort the shape of your cornea, which could lead to inaccurate measurements and a poor surgical outcome.

Skip your eye makeup and eye cream on the day before and the day of your surgery. Your doctor may also instruct you to clean your eyelashes daily or more often in the days leading up to surgery, to remove debris and minimise your risk of infection.

You will need to have someone drive you to and from your surgery. Immediately after surgery, you might still feel the affects of medicine given to you before surgery and your vision may be blurry.

Refractive surgery is usually considered elective surgery — which means it isn’t vital to your health and well-being. For this reason, Medicare and most insurance companies won’t cover the cost of the surgery. So be prepared to pay out-of-pocket for your expenses.

Results
Refractive surgery often can offer you improved vision without the hassle of glasses or contact lenses. In general, you have a very good chance of achieving 20/25 vision or better after refractive surgery. More than 90 percent of people who have undergone refractive surgery no longer need to use their glasses or contact lenses most of the time.

Your results will depend on your specific refractive error and other factors. People with a low grade of nearsightedness tend to have the most success with refractive surgery. People with a high degree of farsightedness along with astigmatism have less predictable results.

Risks
As with any surgery, refractive surgery carries risks, including:

* Undercorrections. If the laser removes too little tissue from your eye, you will not get the vision results you were hoping for. Undercorrections are more common for people who are nearsighted. You may need another refractive surgery (enhancement surgery) within a year to remove more tissue.

* Overcorrections. It is also possible that the laser will remove too much tissue from your eye. Overcorrections may be more difficult to fix than undercorrections.

* Astigmatism. Astigmatism can be caused by uneven tissue removal. This sometimes occurs if your eye moves too much during surgery. It may require additional surgery.

* Glare, halos and double vision. After surgery you may have difficulty seeing at night. You might notice glare, halos around bright lights or double vision. Sometimes these signs and symptoms can be treated with eyedrops that contain a type of corticosteroid, but sometimes a second surgery is required.

* Dry eyes. For the first six months or so after your surgery, as your eyes heal they might feel unusually dry. Your eye doctor might recommend that you use eyedrops during this time. If you experience severe dry eye, you could opt for another procedure to get special plugs put in your tear ducts to prevent your tears from draining away from the surface of your eyes.

* Flap problems. Folding back or removing the flap from the front of your eye during surgery can cause complications, including infection, tearing and swelling. The flap removed during PRK may grow back abnormally.

If you are considering LASIK eye surgery, talk to your doctor about your questions and concerns. He or she can explain how the surgery might benefit you and help put the risks in perspective.

Source: The Daily Star, November 08, 2008