Correcting myopia and astigmatism with LASIK surgery is becoming more acceptable in Singapore. LASIK, the acronym for laser-assisted in situ keratomileusis, is a surgical procedure intended to reduce a person's dependency on glasses or contact lenses. It involves creating a flap in the cornea and using a laser to reshape the underlying cornea tissue. The procedure has proven to be effective, safe and predictable for patients, with a high success rate and patient satisfaction. A recent survey done along Orchard Road showed that 69% of 300 respondents were aware of the procedure, a third of which indicated that they would consider doing LASIK surgery. However, when it comes to the issue of one-eye or two-eye surgery, there is a dichotomy of thought and practice.

One-eye and two-eye Surgery

Presently, all goverment eye centres perform solely one-eye LASIK surgery. This means one eye is operated on first followed by an interval period of at least a few days to weeks before the second eye is done. On the other hand, most eye doctors in private practice are now performing two-eye surgery, where LASIK surgery is done on both eyes at the same time. Doctors call the former unilateral sequential surgery and the latter bilateral simultaneous surgery.

Two-eye LASIK surgery - the local experience

As eye doctors become progressively experienced and confident with the procedure, and to meet the increasing demand from patients, more and more bilateral simultaneous procedures are being done globally. In Singapore, the private sector has taken the lead in performing bilateral surgery. All analysis of LASIK procedures recently performed at hospitals managed by Parkway Group Healthcare showed that bilateral simultaneous procedure accounted for 80% of all Lasik Surgeries done.

A study of 200 bilateral simultaneous LASIK procedures done in a local private practice found that 92% of the cases were within a half-dioptre of intened correction. A dioptre is the measurement of refractive error. There were no cases of infection and no patients suffered loss of best-corrected visual acuity. The few significant post-operation complications that arose were all successfully managed with conservative treatment. The Singapore experience mirrors overseas reports on bilateral simulataneous surgery that it is as safe and effective as unilateral sequential surgery.

It's your choice

One-eye or two-eye surgery? Ultimately, it is the patient's choice. It is important for the patient to understand that while two-eye surgery is as safe and effective as one-eye surgery, it is not necessary better. Most patients, who decide to go for LASIK surgery, are at ease with the thought of bilateral surgery. They simply prefer the convenience of having both eyes done at the same time. Bilateral LASIK is also a practical choice for overseas patients, as they usually cannot stay in Singapore for long.

The future trend

The trend towards bilateral surgery is gaining phenomenal popularity worldwide. Surgeons now know much more about the procedure, how to get accurate results, as well as how to avoid and manage complications. With improvements in surgical hardware and laser machinery, a greater number of surgeons are performing LASIK bilaterally.

Already, bilateral surgery is routinely done in many parts of the world. Most of the top eye institutions offer bilateral LASIK. Any current debate over unilateral versus bilateral surgery may have more to do with custom than statistical risk. Two-eye surgery looks set to be the future trend of refractive surgery.

Consideration for Doing Two-eye Surgery

* Refractive Accuracy
Is there a more accurate result when the eyes are done separately? In other words, do we learn something from the outcome of the first eye's operation that we can apply to the second eye's operation to increase the likelihood of a perfect result? To date, scientific studies have shown that the theoretical refractive accuracy advantage of one-eye surgery does not really have a bearing on real life clinical practice. It has been found that each eye can respond slightly differently and any over or under-correction of power in the first eye does not predict a similar response in the second eye.

* Safety
Is it safer to do the eyes separately? The concern is that a complication, which is not apparent at the time of the surgery, can occur in both eyes hour or days later. The biggest fear is of catastrophic bilateral infection, leading to blindness. Fortunately, the risk of this happening is remote. The incidence of unilateral infection occurring is one in 5,000 to one in 10,000 eyes. For bilateral infections, the real risk is even lower and may be one on 20,000 to one is 100,000. Moreover, most LASIK-related infections and inflammations are easily treatable with eye drops.

* Convenience
Bilateral simultaneous LASIK has many obvious advantages for the patient. Some of these are:
- Less time needed to take time-off from work to go for surgery
- Stress and hassle of going for the same operation twice is avoided
- Medications can be taken once
- Number of visits to the hospital following the surgery is halved
- No inconvenient and uncomfortable spell of unbalanced vision