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 flap 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.
