Contents of this interview was published in The Star newspaper on 9th April 2015
An interview with Dr Stephen Chung:
You are one of the early adopters of laser refractive eye surgery in the country. How has the technology evolved since that time?
The technology has changed tremendously over the years. When I first started 20 years ago, we did a corneal surface procedure using the Excimer laser called Photorefractive Keratectomy (PRK). It had a rather slow healing recovery.
The technology of the lasers and also the procedure has changed and evolved since then. The big change after PRK was the making of a flap before using the laser and this was the LASIK procedure, LASIK allowed faster recovery of vision (from many weeks with PRK to just days with LASIK) and less discomfort for the patient. The flap at that time was created using an automated blade cutter called a microkeratome.
Further advances in technology allowed improvements to be made to the flap creation method by introducing a Femtosecond laser to create the flap. This allowed us to make the flap in a more precise, accurate, and safer way, as compared to using the microkeratome (Blade LASIK).
Improvements in Excimer laser technology have made it possible for better and more predictable surgery outcomes.
Now, the latest evolution of laser technology comes in the form of the SMILE procedure, where the corneal flap is not made anymore.
What is SMILE?
SMILE is short for Small Incision Lenticule Extraction.
It is a procedure that uses only one type of laser - the Femtosecond laser for the complete procedure, in contrast to Femto-LASIK which uses 2 different lasers – the Femtosecond laser to create the flap and the Excimer laser.
The SMILE Femtosecond laser is able to penetrate the surface of the cornea (the front part of the eye) without making any cut and focus on the deeper part of the cornea and carve out a shape called the lenticule.
A small incision is also made at one side of the cornea to allow access to this lenticule and the surgeon is able to remove the lenticule from the cornea. Once the lenticule is removed, the overall shape of the cornea is altered and the prescription/power of the eye will be changed.
What are the benefits of SMILE over LASIK?
In SMILE, there is no corneal flap, unlike LASIK. When there is no flap, there is no worry about flap complications. Eg: the flap moving or dislodging (which can occur in LASIK).
Also by not cutting a flap, we keep the cornea much stronger compared to LASIK, this is especially relevant to those with higher powers or thinner corneas where a lot of the tensile integrity of the cornea is affected by the flap or the greater amount of corneal tissue that has to be removed.
The third advantage is the preservation of the corneal nerves. Where as in LASIK, in the process of cutting the flap, we also cut a lot of the nerves, and these nerves help reduce post op dryness.
So in summary, by not having a flap, you get a stronger post operative cornea, lesser dry eyes, and no flap complications.
Also, for patient’s comfort – because only a small incision is made in SMILE, the patient experiences lesser post op irritation and pain as compared to LASIK, where a big flap incision is made.
Is SMILE better than LASIK?
In certain safety aspects, it is – no flap means no flap complications, and it maintains more corneal strength post op, compared to LASIK. It is also more comfortable, the patient experiences lesser dry eyes (because more corneal nerves are preserved) and less pain after the operation
Vision-wise, results are similar to LASIK. LASIK has been around for a long time, and is a mature technology and procedure giving good and satisfying visual results.
Is SMILE widely available in Malaysia?
At the moment, it is not. There are only a few eye specialist centres in the country that are currently offering this procedure.
Why are so few centres offering SMILE here in Malaysia?
It is the latest, state of the art technology which requires new laser machines. These machines are expensive. Also, not many surgeons in Malaysia have the experience to adopt the procedure; it will take a while before it becomes more widely available.
What is the future of SMILE, where is it heading to? Will LASIK be a thing of the past?
In time to come, SMILE will be the leading choice in terms of cornea preservation and also safer features but for now, both SMILE and LASIK have their own benefits.
LASIK is a good procedure, and it has been giving consistent results. In the near future, eye laser centres will probably offer SMILE side by side with LASIK. This is a similar situation to ASA (Advanced Surface Ablation).
ASA, which was the first generation of laser surgery, has not faded away either. It is still being done as it has its own advantages and provides good results.
So, I believe that SMILE will compliment LASIK as an alternative for patients who prefer its advantages over LASIK.
About Dr Stephen Chung
Dr Chung is a renowned ophthalmologist and laser refractive surgeon. His experience in performing laser refractive surgery in Malaysia for 20 years has made him one of the most sought after consultants on laser refractive surgery in the region.