I've always been told that because I am so nearsighted (-10.5 each eye) that Lasik surgery would not be able to correct my vision fully. Is this still true with this new form? -- Liz Lee, Houston, Texas
That may have been a problem with older technology, but I think the bigger issue at -10 diopters is the safety of the procedure at that level of nearsightedness. In my opinion, it's rare that I feel that someone's cornea is appropriate for Lasik at that level, because it usually requires removal of too much corneal tissue. There's certainly a higher chance that someone at that level will need an enhancement, and the problem is there may not be enough tissue left to do the enhancement.
There's a newer option for people at that level of nearsightedness and it involves putting a lens inside of the eye. It's called a phakic intraocular lens implant. That concept has been around for about 10 or 15 years in Europe. The FDA approved two lenses this past year for use in the United States (Verisyse and Visian ICL). It's a better option for high nearsighted corrections, because we don't have to alter the thickness or shape of the cornea. Consequently, we don't have to worry about the cornea becoming too weak down the road. Also, at that level of nearsightedness, the quality of vision will be better if you put a lens inside the eye rather than drastically altering the shape of the cornea.
Dr. Jim Salz agrees that the phakic intraocular lens implant is a better option when a high level of correction is needed. He adds:
There is a low but serious risk with this surgery, because you are working inside the eye. If you get an infection when putting one of these implants in, you could lose your sight. This hasn't happened so far in the clinical trials, but we don't really know the risk of infection. It has to be less than one per 3,000 to 4,000 cases, because that's the risk of infection with cataract surgery, which is a similar procedure. And the risk should actually be less, because the lens implant is a less invasive procedure and done on younger, healthier patients. You can get an excellent opinion in Houston at Baylor.
I had Lasik seven years ago. Can an enhancement be done to improve my sight and get rid of the halo and bad nighttime vision using this new procedure? -- Randi McFadden, Richmond, Va.
Yes, and I've done that, but candidates need to have a full evaluation. They need to have enough cornea tissue left for the procedure to be safe.
Is it possible to correct presbyopia (aging eyes) with laser surgery? -- Helena Bissinger, Jerome, Mich.
Presbyopia is the natural loss of focusing power of the lens of the eye. When people need reading glasses at 45 or older, that's presbyopia at work. To correct that, you have to do something to the lens of the eye, and Lasik works on the cornea, not the lens. But there are things we do with Lasik to treat the effects of presbyopia, such as monovision or blended vision, where we treat one eye for distance and one eye for near vision. It can hold off the need for reading glasses, but the duration of effect depends on each patient's occupational and recreational vision needs. A fair number of people with this surgically created monovision will find they still need glasses for at least one thing in their life, and most commonly, that's night driving.
