A SURGEON here has cracked the puzzle of a previously misunderstood eye infection, a discovery that could save the sight of dozens of patients each year.

The discovery spells hope for the 20 or so Singaporeans annually who come down with a virus that can lay waste to their corneas. Called cytomegalovirus, the infection was often misdiagnosed, leading to more problems for patients.

Associate Professor Chee Soon Phaik discovered that the virus, which is usually restricted to the back of the eye in patients with weakened immunity - like those with Aids - can also crop up in the front of the eye of healthy people.'When I first found out, I was shocked,' said Prof Chee, who heads the Singapore National Eye Centre's (SNEC) ocular inflammation and immunology service.

The find is expected to change the way doctors diagnose and treat patients with eye inflammation.

Before the discovery, otherwise healthy patients were often given steroid eyedrops, which actually decrease the eye's immunity and allow the virus to grow stronger.

Such misdiagnosis has cost the sight of at least one man here, who needed two cornea transplants because of the virus.

Prof Chee first stumbled upon the disorder in November 2003 when a foreign patient with swollen eyes was referred to her for cornea transplants. She tested fluid from his eyes to see what had caused the swelling, and was shocked to find the presence of cytomegalovirus. This man was given antiviral pills and recovered after three months.

The SNEC has diagnosed about 90 patients with this viral infection. It makes up 20 per cent of its patients with eye inflammation.

Prof Chee's findings will be presented to more than 500 ophthalmologists at a four-day meeting which starts today. It is held by the SNEC to mark its 18th anniversary.

Preliminary results of an SNEC study on patients here who have had a tiny doughnut-shaped eye implant to correct near-vision problems caused by ageing - presbyopia - will also be presented.

The 24 patients here, who have had the implant made by American company Acufocus for at least three months, can now see words just 1mm high, half the height of what they could see without glasses previously.

One of them, finance manager Anne Koh, 52, who has had the implant for eight months, said: 'Without my glasses, I couldn't read text messages on my mobile phone. But with the implant, I can read them now, and I don't feel so old.'

The centre plans to enrol 100 patients. Those interested in joining the trial can call 6322-4500 or 6322-4501.

huichieh@sph.com.sg