That's one of the first questions most people ask about refractive surgery. What they really want to know is: Will I be happy with my eyesight after my operation? Unfortunately, there is no simple formula to determine answers to these questions. Although general guidelines help eye doctors decide who might benefit from refractive surgery, each candidate must be carefully reviewed on a case-by-case basis. That is why you go to your eye doctor for individualized care and advice. Every operation must be considered in terms of a benefit-to-risk ratio for that specific patient. With elective surgery, it always pays to be conservative.
Figuring out if you might be a good candidate for refractive surgery is as much an art as a science. How will your doctor decide if you will be happy with your outcome? The process is inexact. Looking for people with reasonable expectations, eye doctors try to screen out patients who expect perfect results. Of course, what the laser does is science. With excimer laser surgery, your doctor enters a specific set of numbers into the laser's computer, and the software executes the instructions that control the laser pulses. But how does your doctor decide what numbers should be put in the computer? He must consider how your age will affect your wound-healing response and also must enter data in the computer that will produce a result that will work for your individual eyes and lifestyle. It takes long experience talking with many patients before and after each type of procedure to do this well.
Your doctor will want to know if you are happy with your eyesight with contact lenses. If you are, then the physician can attempt to duplicate your prescription with laser surgery. If you are thrilled with your vision with contact lenses that undercorrect your nearsightedness, your doctor can be more conservative in programming your surgical refraction. In other words, by targeting your correction at slightly under 20/20 in the distance, the risk of making you farsighted or overcorrecting you can be diminished. After discussing your personal expectations, your job, and your hobbies - and studying your eye examination and history - your surgeon must pick the exact numbers to put in the computer that, along with your healing response, will determine your future vision. This is the art of vision correction surgery.
Successful eye surgeons want to match your expectations to what they can deliver. Doctors look for indications that patients are highly motivated to improve their vision. Striving to operate on people who will be pleased with their outcomes, ophthalmologists should avoid performing surgery on anyone who expresses major doubts about a procedure. After years of observing patients' reactions to refractive surgery, physicians who specialize in this field start to develop a "sixth sense" about who will be happy with the results. But no matter how long surgeons have performed laser surgery, they continue to learn more from their patients. Such invaluable experience helps doctors identify people who should avoid having these elective procedures.
The range or degree of your refractive error is a key consideration in determining whether you are a good surgery candidate. Your physician will measure your corrected and uncorrected visual acuity. If you are nearsighted, can you read the 20/30 line on the eye chart? Or do you strain to see the big E (about 20/400 on some charts)? Generally, the higher the correction, the greater the motivation to have a laser operation.
LASIK surgery, unlike radial keratotomy (the older, non-laser operation), can improve a wide range of refractive errors, including farsightedness. Nearsighted persons currently can be treated if their refraction is between -1 and -12 diopters - sometimes, depending on the individual case, up to -14 diopters. Although extremely myopic people need help the most, LASIK can leave some of these patients with an unacceptable amount of residual error, meaning that they still will need glasses for distance. So if your correction is greater than -14 diopters, you may want to wait until medical technology has more to offer you. LASIK could improve your vision, but you probably still would have to wear corrective lenses after surgery.
Years ago, in doing refractive surgery before the modern LASIK technique was available, doctors often had to tell extremely near-sighted patients, "We're sorry. You're not a candidate. We can only make your vision about 50 percent better." Some people would respond, "I'll take it! I would like to have thinner glasses. I want to be less helpless without correction." They had reasons for seeking even a partial improvement in their eyesight. For them, better was better, whether better was perfect or not. Other patients would say, "Well. if you only can make my eyesight 50 percent better, why bother having surgery? I would still have to wear glasses even though they would be thinner." For these patients, not having a refractive operation would be the correct choice.
