What are the more common potential side effects? Dry eye and glare while driving at night are possible, but fortunately are much less common than before.
Dry eye was much more of a problem back in the days when a blade, called a microkeratome, was used to make a flap. The depth of the flap incision was less predictable and thicker. This meant more roots of nerves were cut. The result was less sensation by the cornea until the nerves grew back. Less sensation meant less reaction to the ambient air environment, and less reflex tearing. Less baseline tear production caused less lubricity of the surface of the cornea, and a dry sensation.
Even back then, most were restored to normalcy, but over a long time. Nowadays, the depth of the flap incision, because of precise femto-second technology guided by a laser interferometer, the incision is thinner. Less nerve roots are cut. There is less loss of sensation, quicker restoration of nerve sensation occurs and less dry eye. In fact, many patients who seek LASIK have dry eyes exacerbated by contact lenses and report less dryness after the procedure. Most patients do not experience dryness of any sort, and those that do, usually heal in a matter of weeks.
Glare at night in the past was because of imprecise placement of laser spots. With LASIK or PRK, each laser spot lifts off a certain amount of tissue and the sum total of all spots results in duplicating the shape of a contact lens on the cornea, permanently.
However, modern day LASIK is incredible. A tracking system, borrowed from technology developed by NASA, re-aligns the laser to the center of your pupil 500 times a second. That’s faster than the pulsing of the laser or the movement of your eye. There is precise centering, and the result is a smoother sculpting of the cornea. Additionally, the optical zone of treatment has been widened, to greater than that of a standard contact lens, so even when the pupil dilates at night, all of the light is kept in focus. Moreover, there is a feathering of the junction between the untreated and treated areas of the cornea by the laser so there is a smoother transition zone.
All said, most patients say there is less glare at night than they got wearing glasses or contact lenses. One more incredible thing. Keep in mind that you see with your brain, not your eyes. Your brain is constantly suppressing unwanted or extraneous sensations, whether it be glare in vision, or smells or sounds. Over time, usually measured in weeks, extraneous starbursts or haloes are suppressed. That process is an active physiologic response in which actual inhibitory nerve synapses are created. The brain is amazing.
Other potential complications
Severe complications are rare, and indeed are less frequent than that of contact lenses. The biggest threat with long-term contact lenses is a corneal infection, which can cause a scar in the visual axis. Ordinarily, the primary defense against infections on your cornea is simply blinking and washing away the bacteria before it can attach. A contact lens interferes with this, and indeed, can trap bacteria. With LASIK, the blinking action is as it should be normally. Infections from LASIK surgery are extremely rare.
Another complication is ectasia. This is a weakening of the cornea such that the tectonic strength is less than that of the pressure from your eyelid and intra-ocular pressure. The cornea gets distorted. Pre-operative tests used to rule in candidacy look for thinness of your cornea or weak areas that protrude to rule out a predilection to ectasia. However, nothing is 100%, as ectasia can occur naturally, even without surgery, in a condition called keratoconus. Fortunately, ectasia is rare, and even more fortunately, can now be treated. The treatment, called corneal cross-linking, stiffens the collagen. This treatment is not available at most corporate LASIK centers, but is done here by the doctors of Princeton Eye Group. Also, new and improved rigid scleral contact lenses most often can restore good vision.
Please take all surgery seriously, particularly if it involves your eyes. Wills Laser Vision is not the highest in volume LASIK surgery but is considered by industry to be the paragon of excellence. Caring about safety is first and foremost.