Lasik safe if done well and within guidelines
I REFER to the article, "Woman aims to reopen Lasik claim" (ST, Dec 13), about Ms Doris Ong's predicament, and the letters, "Monitor long-term effects of Lasik surgery" (ST, Dec 13) by Mr Michael Heng and "Lasik surgery safe and effective" (ST, Dec 9), by Dr Lee Hung Ming of The Eye Institute.
With regard to Ms Ong's predicament, there are two techniques which will correct much or all of her remaining myopia.
In Lasik, a flap is created and the comea is thinned to the appropriate amount by an Excimer laser. If the remaining cornea bed is too thin, no more traditional treatment is possible.
However, one of the original methods of performing Lasik in the late 1980s was to laser the back of the Lasik flap (this technique was abandoned because it was technically difficult).
Recently, there have been a number of reports detailing new techniques to laser the back of the Lasik flap to achieve a correction in a cornea with a remaining bed that was apparently "too thin".
I performed this procedure on a patient on June 11, with great success.
Another emerging method is to carry out Excimer laser treatment on the superficial cornea but to add a chemical called Mitomycin to prevent scarring. This method has less of a follow-up history but some doctors in Europe and the US are reporting success.
With regard to the report by the National Institute for Clinical Excellence (Nice), it should be noted that Lasik is surgery and therefore should be called "Lasik surgery". As with all surgery, complications exist.
The Nice report is an excellent review of the Lasik procedure and its complications. It is a well-balanced report but because of how it was presented in the article, "Block on laser eye surgery in Britain" (ST, Dec 6), and the letter by Mr Heng, an unintended negative bias has been associated with the article.
In the Nice report, it was stated that "specialist advisers did not highlight any specific concerns regarding efficacy of the procedure, provided that the degree of refractive error is within accepted criteria". They wrote that Lasik "is an established procedure".
They also wrote that "some complications, such as halo formation, were much more common with earlier laser machines". The new-generation machines have eliminated this groblem to a great extent an they knew that they were reporting on old data.
"It is unclear whether those lost to follow-up had poorer outcomes and thereby chose not to continue. This makes it difficult to accurately assess the'safety and efficacy of the procedure"
In my experience, Lasik patients with excellent vision ind less need for follow-up whereas patients who are unhappy with their vision always retum, negatively biasing the follow-up results.
Also, they reported that procedures were done by "non-ophthalmologists (GPs), by ophthalmologists without higher surgical training (associate specialists) and by certified ophthalmologists with sub-specialty training in corneal disease".
In Singapore, all Lasik surgery is done by certified ophthamologists and most of the leading Lasik surgeons have internationally recognised sub-specialty training.
The Nice report also stated that they did not look at the question of whether "Lasik should be performed simultaneously on the same day or sequentially". Most major centres in Singapore perfom Lasik sequentially, on different days, for added safety.
Finally, "a significant number of case reports of complications" have also been published". However. case reports "can potentially overestimate complication rates due to publication bias".
Having reviewed the Nice report and the letters by Mr Heng and Dr Lee, I believe Lasik's success and efficacy lies somewhere between the optimism of Dr Lee and the pessimism of Mr Heng.
As the doctor who first started Lasik in Singapore in 1996, I would like to make it clear that Lasik is a safe and efficacious procedure if done well, properly and within the guidelines, like any other surgical procedure.
Dr Jerry Tan Tiang Hin
Source: Straits Times© Singapore Press Holdings Limited. Reproduced with permission.