Traditional cataract surgery remains 'gold standard'

The College of Ophthalmologists wishes to address certain points inthe article, "New cataract surgery cuts blindness risk" (May 9).

Phacoemulsification using ultrasound energy, the "traditional cataract surgery" mentioned in the article, has been performed on thousands of patients here since the early 1990s.

The procedure has undergone tremendous improvements over time. When performed by competent surgeons, it results in a very low rate of endothelial cell loss and subsequent corneal decompensation or damage.

Peer-reviewed medical studies published over the last six years show a range of mean endothelial cell loss of between 1 per cent and 10 per cent.

A 2004 study showed that even when the procedure was performed by a junior doctor, the average endothelial cell loss was only 11.6 per cent.

The article's figure of up to 40 per cent endothelial cell loss after standard phacoemulsification is thus inaccurate and may occur only in rare cases when complications arise.

While the use of the femtosecond laser may theoretically reduce the amount of ultrasound energy required, the laser itself is high-energy. It is too early to tell whether the cumulative energy from the laser plus the reduced ultrasound is safer than the conventional amount of ultrasound energy in phacoemulsification.

The results from the National University Hospital showing that "half (of the patients) experienced negligible cell loss" after undergoing femtosecond laser-assisted cataract surgery is unproven. Without performing a proper study over a period of at least six months, it would be premature to draw such conclusions.

While femtosecond laser-assisted cataract surgery holds great promise and may become more widely acceptable in the future, we need to factor in the high costs, logistic hurdles during the procedure itself and the relative paucity of comparative data at this early phase of its use worldwide.

The current phacoemulsification technique has set an extremely high standard in safety, comfort, expediency and outcomes over the years. It remains to be seen whether the femtosecond technological evolution can match or surpass this high benchmark.

When compared to conventional phacoemulsification, which already carries a low risk of blindness, it is too early to claim that femtosecond laser-assisted cataract surgery can reduce the risk of blindness.

We hope to allay the fears of those who will be undergoing or have undergone standard phacoemulsification cataract surgery, and emphasise that at present, it remains the gold standard for cataract treatment.

Yip Chee Chew (Dr) Honorary Secretary, The Council, College of Ophthalmologists, Singapore Academy of Medicine of Singapore