I have dry eyes and have been told that Lasik surgery would make this condition worse. Is it possible that new Lasik technology might someday make this surgery an option for me? -- Sunny Monroe, Bothell, Wash.
The bottom line is that dry eye needs to be treated prior to surgery if it's a pre-existing condition, and we have the tools now that allow us to treat dry eye in most patients.
As for new technologies, it's possible that Lasik with the laser-created flap may cause less of a problem with dry eye, because you can create a shallower flap. The deeper the flap, the more corneal nerves are affected by the surgery. These nerves sense dryness and tell the tear glands to make more tears. So if you cut through those, they don't work for a while and need time to regenerate. So the shallower the flap, the less effect.
How often does laser surgery need to be performed to be maintained? And what is the success rate? -- Marisa Bodell, Santa Fe, N.M.
Ten percent of patients have to have enhancements or touchups one time. This is typically determined within the first year after surgery. The higher the correction, the higher the chance of the need for an enhancement.
Dr. Salz adds:
For up to about – 8 diopters nearsightedness and up to about + 5 diopters farsightedness, the success is very high, with more than 90 percent of patients achieving better than 20/40 vision. If we did the surgery on a stable eye, the surgery will last. We don't give you a warranty that your vision isn't going to change, but the majority of patients I've operated on have had one surgery and they never come back.
With wavefront-based Lasik, most studies show that more than 90 percent of patients obtain 20/20 vision or better.
What steps can I take to ensure the safest possible experience for laser surgery? -- Peter Lowe, Stamford, Conn.
Go to a reputable laser center focused on the patient and not on volume. I think that major institutions, major universities are always focused on the patient; I don't know of any university that is performing high volume surgery, e.g. 30 to 40 patients a day. Lasers need to be recalibrated during the surgery day to ensure accurate treatments. We recalibrate our laser between each eye of each patient to ensure the most accurate results. In addition, high volume means a higher chance of something being overlooked. Also, you want to be able to meet your surgeon before the day of surgery, particularly before you're on the table.
There's not a lot you need to do preoperatively outside of not wearing eye makeup, perfumes or colognes. If you're wearing soft contact lenses, stop wearing them anywhere from three to five days before your screening. Rigid lenses need to be out for weeks, depending on how long you've worn them.
Dr. Jim Salz, clinical professor of ophthalmology at USC, answers the following questions:
Does PRK (photorefractive keratotomy) yield similar results? -- Stephan Edwards, San Diego
PRK was the first laser procedure approved, and still gives excellent results.
With PRK, we don't make a flap; we take the surface skin (epithelial layer) off the cornea. You can take this layer of cells off by rubbing it or loosening it with alcohol, and then you apply the laser to the next layer. The laser part of the surgery is exactly like Lasik. Then you put a bandage contact lens on to protect the eye while this epithelial layer grows back, and the eye has the same chance of good vision as with Lasik.
It's a little bit safer than Lasik because there's no flap, but the reason we don't do that operation more often is it takes longer for the eye to heal, and there's more discomfort in those initial three days than with Lasik. The Navy uses PRK on its pilots, but not Lasik. The thinking is if you have to be ejected from a plane, the forces that might hit the eye could displace the flap. But other military people can have either LASIK or PRK.
