Risks of LASIK and Safer LASIK practice

Every surgical intervention besides its benefits may carry some risks. Even though LASIK is one of the most developed operations ever invented by mankind, although very rarely, it is possible that it may cause some undesired results. All the risks associated with LASIK operation are very rare and just a few of them have a long course. First of all, LASIK doesn't cause blindness according to all the prestigious scientific literature. We heard some rumors about some patients from India, Turkey, Europe, Canada and the US, but we couldn't verify the facts. If you know anybody suffering from a LASIK related vision loss, please advise him/her to contact us. We will provide a free service and assistance for them. We are confident that all of the possible LASIK complications can be handled by good cooperation without any significant vision quality loss.

What do we do to lower the LASIK risks:

We have created a summary of safe and high-quality LASIK practice, called Good LASIK Practice Guidelines (GLPG). GLPG is a result of years of experience and academic research. If GLPG is strictly applied, LASIK complication risks fall below 1% (which is around 2 to 6% in general [refraction deviation not included]) and also this ensures overall medical quality and evident visual outcome.

We always use the eye-tracker. This ensures a well-centered homogenous treatment. Many centers in Turkey and in the world don't activate eyetracking since it is time consuming.

We always use new original disposable blades for each patient. At each use of the microkeratome, the cornea may scratch the blade. Used dull blades may cause imperfect cuts. Aiming for the perfect results, this malpractise is unacceptable for us.
Be aware: some eye hospitals in Turkey and around the world do not change the blades from patient to patient: an open invitation for contagious diseases such as hepatitis and AIDS.

Even though all of the microkeratome systems we use have an alarm for inadequate vacuum levels, our refractive surgeon always checks the pressure manually and reconfirms the status by cooperating with the patient.

Our refractive surgeons always inspect and check the microkeratome themselves.
We always simulate the operation before performing it on our patients. This enables us to foresee possible laser related problems and it also gives us the chance to correct errors before our patients experience a problem.
Since our surgeons are refractive (corneal) surgery specialists, we are not commited to LASIK option. If your eyes need special treatments like LASEK, PTK, AK etc… we can help you with the solution that suits your special need.

We devote the time necessary for each patient. More time devotion means better results, less error and more content patients. One of the most well-known centers in Istanbul, Turkey has a re-operation (second laser treatment for residual myopia, hyperopia or astigmatism) rate of 21%, and ours is only 0.5%.

All of the pre-op examinations (before LASIK), LASIK operations and post-op examinations (after LASIK) are conducted by the same refractive surgeon. We believe that direct information is always better than indirect information.

Our complication rate for the flaps is around 0.2%. We encountered a few cases of SOS (Sands of Sahara) last year. We worked on it and since then, we haven't had any SOS cases. In summary, our total complication rate is under 1%. None of our patients have a vision less than the driving license requirements except the ones with severe amblyopia (lazy eye).

LASIK risks in general

A few weeks after LASIK surgery, haloes around bright light sources may be seen. In general this effect fades away with time.
Sometimes desired correction may be less or more than planned and some astigmatism may be induced. This problem can be solved by a touch-up laser treatment. Re-treatment is usually necessary for higher and more complex prescriptions.
If the vacuum of microkeratome is less than normal, an irregular/incomplete flap may be created on the cornea. Sometimes this might be due to patients' excessive squeezing or microkeratome malfunction. In this case, the LASIK procedure may be postponed or different Laser modalities may be considered.
Very rarely, epithelial cells may migrate under the flap. This may cause blurry vision. To solve this problem, the surgeon irrigates and washes these cells away. Sometimes if the problem is persistent, these cells can be killed with topical application of alcohol.
Another rare case is when a reaction (colonies of white blood cells) may be seen under the flap. This condition, which causes cloudy vision, is called DLK (Diffuse Lamellar Keratitis) or SOS (Sands Of Sahara). Grease and debris of microkeratome motor, patients' own secretions have been accused for this condition. Flap interface wash and drops with steroids may be used to end the reaction.
In the early days after treatment, although occurring in very rare instances, the patient may involuntarily displace the flap (such as during sleep, play or fight) causing wrinkles, folds or striae on the flap. In this case, the flap is repositioned and swollen, if needed.
Very rarely, the flap may be free without a hinge (free cap or free flap). Then, laser treatment is performed and the flap is repositioned (In the past, this was the routine).
Infection is another rare risk. It can be handled with antibiotic drops. General statistics show an infection rate of 1:20 for LASIK versus contact lens use.
After LASIK, due to the decrease of corneal tear reflex and manipulation of the tear glands (which is located under the eyelids), the eyes may be dry. This is especially obvious for elderly people, who have a natural tendency for the condition. Artificial tears and lubricant gels might be helpful. Normally after a few months, the complaints related to dry eyes disappear. Very rarely, a punctum plug to keep the tears in the eye might be needed.

International Studies About LASIK complications

Frequency of the complications seen during and after LASIK Surgery
One of the most well-known studies about LASIK complications is the CRS-USA study. Published in April 1998, the study was an evaluation of 1800 eyes that had undergone LASIK surgery.

CRS_USA STUDY: COMPLICATIONS DURING LASIK SURGERY
(Intra-operative complications, TOTAL %1.2)

Type of Complication	Frequency
Irregular flaps	0.03%
Epithelial damage	0.47%
Thin flaps	0.38%
Too small flaps	0.38%

Please note that, this kind of microkeratome-related complications decreases with the advance of microkeratome technology. More recent large-scale studies such as, Tham & Maloney (n=3998), published in 2000, found this type of complications only 0.7%, in total.
Patients should realize that the incidence of such complications is generally very low. Nevertheless, in the event that one should occur, most surgeons will not proceed with the laser ablation at the time. Irregular cuts rarely lead to significant visual loss, and usually the surgeon will simply end the procedure that day and re-schedule the surgery a few months later. After 3 months of follow-up, it is found that there is no significant vision difference between patients who experienced complications during LASIK surgery and the ones who did not (CRS_USA study).
The CRS_USA study also summarized the complications seen after the LASIK surgery. The details of post-op complications are as follows:

CRS_USA STUDY COMPLICATIONS AFTER LASIK
(TOTAL %5.8)

TYPE OF COMPLICATION	FREQUENCY
Corneal Edema (Swelling of the cornea)	0.6%
Persistent Epithelial Defect	0.5%
Corneal scarring	0.1%
Significant glare	0.2%
Persistent Discomfort	0.5%
Epithelial in growth	0.6%
Flap (cap) thinning	0.1%
Interface debris	3.2%

It is worth noting that interface debris - retained metallic particles, lint, etc. under the LASIK flap - almost always causes no harm to the health or vision of the eye. Since interface debris is accepted as a non-relevant complication for vision, it has been removed from many studies published thereforeafter. From this point of view, the total LASIK complication rate may be revised as 2.6% for the CRS-USA study. None of these complications resulted in a loss of two or more lines of BCVA (Best Corrected Visual Acuity), and there was no occurrence of infection amongst the study population.
According to the Emory study (1999, n=1062 eyes), intra-operative (during surgery) complication rate has been found to be 1.8%. During this study laser treatments of 17 patients have been postponed due to microkeratome related flap problems.
Another study, Lin & Maloney (1999, n=1019 eyes) has reported a 2.2% total intra-operative complication rate.