Does Lasik surgery successfully correct severe astigmatism?
— John Barada, Reno, Nev. Yes, with limitations. Most of the FDA lasers are approved for up to about 4 diopters of astigmatism correction, which covers 98 percent of the population. Some astigmatism irregularities indicate a problem with the cornea, which indicates you’re not a great candidate for refractive surgery. 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
