Most patients have many concerns about the LASIK procedure. Some of the more common ones are addressed in this chapter.
As with any form of surgery there is a possibility of complications arising, but in the hands of an experienced surgeon these are few and far between. Complications are most likely to occur if the surgeon ignores warning signs and proceeds without knowledge of the possible consequences. Poor technique and old instrumentation are also contributing factors.
Fortunately, most complications can be treated. Studies from around the world have shown that to date, no patient has lost his or her eye from a LASIK procedure.
LASIK requires patients to keep their eye as still as possible during the procedure. They should keep their gaze focused on the fixation light for the procedure to be done accurately. Good fixation of the eye is essential to ensure good centration and minimize the occurrence of halos and glare post-surgery. Although small movements of the eye (hippus) may occur during surgery, these can be compensated for by the laser’s eye tracker. All modern lasers are equipped with very fast eye trackers. Despite this, the best way to ensure good laser centration is for a patient to practice fixing his gaze.
The thought of having your eye cut and lasered leads some people to think that LASIK is painful, but this is not true. Many patients have remarked how surprisingly painless the whole procedure is. At most, patients may experience a little “foreign body” sensation in their eyes after the procedure, but this can often be easily relieved with mild painkillers like Paracetamol.
Patients have also asked if there will be any bleeding as a result of a LASIK procedure. Generally, this does not occur. Slight bleeding may only occur in patients who are chronic contact lens wearers. Prolonged contact lens use can lead to oxygen deprivation of the eye, causing tiny blood vessels to grow into the rim of the cornea. When the microkeratome or femtosecond laser cuts these blood vessels in the course of creating the flap, there may be slight bleeding. However, this bleeding is usually minimal and is not a cause for concern.
Some patients wonder if LASIK results in a person having a weaker cornea or eye. If done properly, LASIK has no effect on the strength of either the cornea or the eye. The LASIK flap should be as thin as possible and the remaining bed should be at least 250 microns thick.
Although it is a very remote possibility, vision of some patients who undergo LASIK may end up worse than before. However, this scenario is extremely unlikely, especially in the hands of an experienced surgeon with good surgical technique.
Scarring is another concern that many patients have. Laser surgery has no visible effects to one’s eye, face or eyelids. Some patients may develop very mild swelling of the eyelids after surgery, but this is temporary and often subsides within a week. Well-performed LASIK surgery is undetectable, even with special instruments used by ophthalmologists. A faint C-shaped line is the very most one might see, but this disappears the day after surgery. It may re-appear 6 weeks after surgery, but will disappear again after about 1 year.
Occasionally, patients may have a “blood shot” eye after LASIK (see Figure 12.3, page 80). The redness is due to bruising of the eye when the suction of the microkeratome or Intralase is applied. This is more common in patients who have very small eyes and those who are unable to fix their gaze well. Though it may look frightening, the redness will disappear within 1 day to a week. There is no permanent consequence to the eye.
Theoretically, it is possible for the LASIK procedure to be performed on both eyes at the same time (bilateral simultaneous LASIK). This is unnecessary and if it is done, it is often for the surgeon’s convenience.
Bilateral simultaneous LASIK can result in bilateral eye infections which may lead to a loss of vision in both eyes. Studies have shown that treating one eye at a time (sequential surgery) makes the treatment of the second eye more accurate. This is because the doctor would have been able to learn about a patient’s individual response to treatment from the first procedure.
The time frame between the treatment of the first and second eye in sequential surgery varies with the power of the eyes being treated. This can range from 1 to 2 weeks after the first operation if the powers are low, or when visual stability has been achieved (usually 3 to 4 weeks after surgery) for patients with high myopia.