What is LASIK?
LASIK is a surgical procedure using the Star4 excimer laser to correct nearsightedness (myopia), farsightedness (hyperopia) or nearsightedness with astigmatism. In LASIK, a thin flap of surface corneal tissue is created using a device known as a microkeratome. This is done to allow access to the underlying corneal tissue known as the stroma. With the stroma exposed, multiple pulses of Star4 excimer ultraviolet light are applied to the cornea in a computer-controlled pattern, in order to remove a precise amount and pattern of stromal tissue. Therefore, following replacement of the flap, the net result is that the front surface of the cornea is reshaped (for nearsightedness or myopia, this includes flattening of the central curvature of the corneal surface). By reshaping the central cornea curvature, the focussing point of light rays entering the nearsighted eye (with or without astigmatism) is brought closer to the retina (the sensitive tissue lining the back of the eye that acts like the film in a camera) and the uncorrected distance vision is improved. Farsightedness can be corrected by reshaping the central cornea curvature so that it becomes more steeply curved, again allowing light rays to be brought closer to the retina.
In the clinical studies of the VISX Excimer Star S2 Laser System for nearsightedness, farsightedness and astigmatism, the results of the 12 months after surgery were:
- A. Without the help of glasses
- 94% mildly nearsighted eyes could see 20/40 or better
- 91% mildly nearsighted eyes with astigmatism could see 20/40 or better
- 90% highly nearsighted eyes with or without astigmatism could see 20/40 or better
- 95% moderately farsighted eyes could see 20/40 or better
- B. With the help of glasses*
- 99% mildly nearsighted eyes could see 20/40 or better
- 98% mildly nearsighted eyes with astigmatism could see 20/40 or better
- 99% highly nearsighted eyes with or without astigmatism could see 20/40 or better
- 99% moderately farsighted eyes could see 20/40 or better
* Data collected from eyes that could see 20/20 or better with glasses before surgery
Even though vision improves without glasses, some patients may need and enhancement, glasses, or contact lenses after LASIK. LASIK does not eliminate the need for reading glasses. NOTE: you may need reading glasses after laser surgery even if you did not wear them before.