New technologies to detect glaucoma

Dr Wong's (left) team, with specialists from Seri, developed the Aglaia system to analyse retina images to identify early signs of glaucoma.
Dr Wong's (left) team, with specialists from Seri, developed the Aglaia system to analyse retina images to identify early signs of glaucoma.ST PHOTO: ONG WEE JIN

A*Star researchers develop software that quickly processes images of eye to spot signs

Glaucoma - the eye disease dubbed "the thief of sight" - could lose some of its sting, with new imaging processing software developed by researchers from the Agency for Science, Technology and Research (A*Star).

The researchers believe that their technology can offer a faster and more accurate way to capture early signs of the disease, which causes build-up of pressure in the eye and damages the optic nerve.

The chronic ailment affects about 3 per cent of Singaporeans aged 50 and above, and accounts for 40 per cent of blindness here.

But there are no early tell-tale signs, such as blurred vision or dark spots. Hence, nine in 10 patients do not know they have the disease until it is too late.

The current gold standard for diagnosis is manual analysis, where eye doctors assess images of the eye to look for optic nerve damage.

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However, this is a tedious process and evaluations could vary among assessors, said Dr Damon Wong, from A*Star's Institute for Infocomm Research, who co-led the development of the technology.

"There was a strong need to develop something automated, objective and suitable for mass-screening," he said.

Dr Wong and his team from the Ocular Imaging Department worked with specialists from the Singapore Eye Research Institute (Seri) to develop a system called Aglaia: Automatic Glaucoma Diagnosis and Its Genetic Association Study through Medical Image Informatics. In mere seconds, it analyses images of the retina and processes them to identify signs of glaucoma.

The system could be rolled out to polyclinics, general practitioner clinics and optical shops as soon as this year, following a successful two-year trial on close to 2,000 people. The group is in discussion with several healthcare companies to commercialise it.

Meanwhile, Dr Wong's team has started on another project: Agar - Angle closure Glaucoma Risk assessment system.

It is able to differentiate between two types of glaucoma - open-angle and angle-closure - by analysing 3D images of the eye.

Open-angle glaucoma is a slow, progressive form of the disease. In angle-closure glaucoma, the change is more sudden - the eye's drainage system suddenly closes or becomes blocked, causing eye pressure to shoot up and leading to sudden blindness and acute eye pain.

There is no cure for the disease, but the type of glaucoma affects how it is managed, whether by surgery, eye drops or injections.

Currently, doctors tell the two forms of the disease apart through gonioscopy - placing a hand-held lens on the eye to make an assessment. But this is uncomfortable and risks damaging the eye.

The Agar method is painless and risk-free, said Dr Wong. A two-year clinical trial with Seri started last October to validate the system's accuracy.

"Eventually, we hope to have a system that can be used to diagnose a range of eye diseases, not just glaucoma," said Dr Wong.

Assistant Professor Baskaran Mani, a senior clinical research fellow at Seri, said glaucoma screening in the general population has been challenging. This is mainly due to the lack of simpler and cost-effective screening methods, such as having automated tools that can interpret images of the eye without the help of a glaucoma specialist.

"The two technologies may, together, be used to detect glaucoma to prevent progression to blindness in high-risk groups in our population in the future," he said.

A version of this article appeared in the print edition of The Straits Times on January 15, 2016, with the headline 'New technologies to detect glaucoma'. Print Edition | Subscribe