Risks, Side Effects and Concerns
Is LASIK safe? What if my eyes move?
LASIK is safe. The chances of complications arising are very remote, especially in an experienced surgeon's hands.
Eye movement can be controlled with special techniques, however the best method to control movement is for the patient to practice fixing his gaze.
Small movements of the eye (hippus) will be compensated for by the Laser's eye tracker. All modern lasers have very fast eye trackers.
Is LASIK painful?
No, it is not. LASIK is performed under topical eye drop anesthesia. No injections or general anesthesia are needed. Patients will only feel a slight pressure from the suction device on the eye.
In fact, some patients have remarked how painless the operation is.
Will there be bleeding?
Generally there is no bleeding.
Chronic contact lens wearing causes tiny blood vessels to form at the rim of the cornea. The edge of the LASIK flap can transect these blood vessels and cause some slight bleeding.
Will I look different? Will my eye have a scar after the procedure?
There are no visible effects of laser surgery to the eye, face or eyelids. Some patients develop very mild swelling of the eyelids after surgery, but this is temporary and will subside in a week.
In well-performed LASIK procedures, there is usually no scar; at most a faint C-shaped line will show at the edge of the flap. Usually the edge of the cut will disappear the day after surgery and the cornea will look normal, as if no surgery had been done. It may reappear 6 weeks after surgery and will disappear again after about one year.
Does LASIK make the cornea or the eye weaker?
If proper standard practice is followed, LASIK does not make the cornea and the eye weaker.
The LASIK flap does not contribute to the strength of the cornea. If the bed of the remaining cornea is too thin (less than 200 to 250 microns), the cornea can weaken and cause a regression in the patient's correction. This is due to the progressive bulging of the cornea (corneal ectasia).
Is it possible for my vision to end up worse than before?
Yes, it is possible. However in the hands of an experienced surgeon this is only a very remote possibility.
Even though LASIK is a complicated procedure, with good surgical technique and surgeon's experience all patients should have minimal risk of their vision ending up worse than before.
How long will it take for my vision to stabilize/recover?
Though this depends on many factors, generally most LASIK patients will experience an improvement in their vision and great reduction in refractive error within the first 24 hours.
If the patient has a very low refractive error - between 1.00 to 3.00 diopetres (100 to 300 degrees) - visual recovery will be very rapid. For patients with refractive error between 3.00 to 6.00 diopetres (300 to 600 degrees), recovery is rapid. For patients with refractive error in the range of 6.00 to 10.00 diopetres (600 to 1000 degrees), visual recovery is moderately quick. For those with patients with refractive error of 10.00 diopetres (1000 degrees) or more, recovery can take more than 2 months for full stabilization. All can move around without difficulty after the first day of surgery, and many return to work one or 2 days after the procedure.
What are some side-effects of surgery?
Immediately after LASIK, the patient will experience discomfort for 2 to 3 hours. The eye will be slightly tender to the touch and the patient may experience a 'sandy' feeling in the eye. This is due to the very fine C-shaped linear cut made on the cornea which is similar to a paper cut on the finger.
For the vast majority of cases, if the eye is kept gently closed after surgery, discomfort will diminish rapidly. If the patient takes a 2 to 3 hour nap, the discomfort will disappear almost completely. Most patients require only mild painkillers (e.g. 2 tablets of paracetamol) after surgery. The patient will usually feel very comfortable six to eight hours after surgery and by then vision should have improved significantly.
Most patients treated for myopia will be slightly hypermaetropic after LASIK. Patients over 40 years of age will initially have difficulty reading close up. After 2 to 3 weeks they will find their near vision return to normal. Patients over 45 years of age who have their eyes fully corrected for myopia and astigmatism require a set of reading glasses after surgery. On the third day after LASIK patients will experience 'Vaseline' vision, a slight cloudiness similar to a soft-focus filter being placed over their eyes. Patients should not worry as this is a normal occurrence. This is a result of corneal swelling. The cloudiness will be more severe in patients who have undergone correction for very high refractive errors.
Glare will also increase in all patients, especially those with 6.00 diopetres (600 degrees) and above of myopia before LASIK. Glare usually disappears after one to three months. If it does not disappear after 6 months, it will most probably be permanent. In many cases night glare continues to improve even after 6 months. With newer lasers like the Wavelight Eye-Q laser, the problem of night glare post-LASIK has almost been eliminated completely. Many patients treated with this laser feel that their night vision is better after LASIK.
Night glare now rarely occurs even in patients who have large pupils and have been treated for very high refractive errors. Despite this, they should still be warned of this side effect prior to surgery. Patients who have decentered laser treatments will also be prone to night glare.
What are some complications that can occur during surgery?
Complications are a rare occurrence, particularly if you are in the care of an experienced surgeon. The types of complications that can arise include a torn and shredded flap, usually due to poor technique and old instrumentation. A poor flap is possibly due to a blunt LASIK blade. No blade should ever be used more than once.
In rare cases, epithelial cells (the most superficial layer on the surface of the cornea) may deposit under the corneal flap.
These cells can sometimes multiply and obscure vision. These cells can be easily removed by opening the flap as in an enhancement1 and flushed out. There is no detrimental effect to the patient, both vision-wise and to the eye if done early.
What is a free cap? If I happen to have one how does it affect me?
A free cap is where a patient's corneal flap may be cut off. Reasons for this happening could include the loss of suction and fixation on the eye, unnecessary pulling on the eye by the surgeon or a sudden movement by the patient.
The new IntraLase® laser in All Laser LASIK cannot create a free cap.
To an experienced surgeon, a free cap is usually not a severe complication. The cap is replaced and allowed to dry and adhere to the corneal bed surface.
Usually no stitches are required. Once attached for 24 hours, the chances of a cap being lost are negligible. Should such a situation arise, a lost cap will usually result in severe scarring and poor visual acuity. To rectify the situation, complicated surgery would be required with the aid of a donor eye.