31 Dec 2011
By: FENG ZENGKUN
HALF of the world's blind people suffer from the condition, and treatment for it remains too costly for many patients in developing countries.
But scientists here may have come up with a way to treat cataracts, an age-related eye disease, at a fraction of the cost of current operations.
They have patented a low-cost medical device and plan to market it in countries such as China, where treatment for the disease is not subsidised by government programmes.
The team is from the Singapore-Stanford Biodesign programme, a collaboration between Stanford University in the United States and local agencies, including the Agency for Science, Technology and Research (A*Star).
Cataracts are a disease where the clear lens of the eye becomes cloudy because of ageing, resulting in a blurring of vision. It cannot be prevented, and more than 80 per cent of Singaporeans over the age of 60 have some form of the disease, according to the Singapore National Eye Centre.
It is set to become even more widespread here as one in five Singaporeans will be 65 and older by 2030.
The cloudy lens is difficult to remove because surgeons have to be careful not to damage the cornea, which covers the eye, and the supporting structure to the lens.
In Singapore, surgeons make a 3mm cut in the eye, insert a thin instrument that uses ultrasound waves to break up the lens, and then suck the smaller pieces out.
An artificial lens is implanted and the patient can see within a day.
Dr Lennard Thean – head of the Cataract, Lasik and Refractive Surgery division at the National University Hospital who helped the scientists to refine their device – said the ultrasound operation can cost up to $5,000 for each eye, depending on the artificial lens used.
In Singapore, this is usually covered by a combination of Medisave and insurance policies, but patients in other countries such as China have to pay the fee out of pocket.
The alternative in these other countries, said the scientists, is a cheaper but more dangerous operation, where a large cut is made on the eye so the cataract can be removed in its entirety without being broken up.
Patients can take up to a week to recover from this method.
The scientists' prototype provides a middle ground between these two ends of the treatment spectrum, they said.
Their instrument is entirely mechanical, which will make it cheaper than the ultrasound method, although the scientists declined to comment on the final product's likely cost. At the same time, because the device is thin, it does not require a large cut on the eye, and recovery time can be as short as a day.
Their miniature instrument has a net of wire hooks at one end. After a small cut is made in the eye, the instrument is inserted and the wire hooks close around the cataract.
The hooks slice the cataract into smaller pieces, which are sucked out through the cut in the eye using a separate device.
"Combining a vacuum function with the instrument would have made it more expensive and difficult to use," said Dr Thean.
Dr Henry Ho, a urologist at Singapore General Hospital and part of the team, said the scientists are applying for grants to further develop the device, and plan to start trials by 2013.
Part of the work going forward is to make sure the product can be manufactured at a low-enough cost for the poorer areas of developing countries, said the team.
If all goes well, the product could be sold within three to five years.
Email: zengkun@sph.com.sg
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