Almost every day, someone here is diagnosed with diabetic macular edema, a leading cause of blindness among working-age people.
The tragedy is that many show up for treatment too late - by which time much of the damage is done.
Macular edema costs Singapore more than $38 million a year in lost work, according to the Singapore National Eye Centre (SNEC).
The amount is based only on time off needed for treatment, and does not include loss of productivity due to loss of vision or the cost of treatment, said Associate Professor Gemmy Cheung, deputy head of medical retina at the SNEC.
With treatment, sufferers can stop their eyesight from getting worse. But many seek treatment only after their vision has deteriorated significantly - said Professor Wong Tien Yin, SNEC medical director.
By then, their eyesight is so bad they cannot legally drive and, without treatment, half the people with this problem will lose two lines of vision within two years of diagnosis. (see chart)
A typical eye chart has eight lines - losing two lines means the person is able to see only the top six lines.
Prof Cheung said losing three lines means needing objects to be double their size in order to see them and is a significant deterioration of vision.
Added Prof Wong: "Full or partial vision loss can lower work participation, increase absenteeism and cause preventable deaths."
About 25 new patients start treatment at the SNEC every month, with four in five aged 40 to 60 years. They need injections monthly for the first three to six months, then at longer intervals.
They need two to three injections in the second year and most can stop after that with no further deterioration of their eyesight, as long as they keep their diabetes under control, said Prof Wong.
He said patients who start treatment early can be treated effectively with a generic drug called Avastin, which costs $640 an injection, or $240 after subsidy.
About 30 to 40 per cent of patients will see improvement in their vision, while almost all the rest will see no worsening of their sight.
For the majority - those whose eyesight has deteriorated significantly - there is a more expensive drug, Eyelea, which can restore more of their lost vision within the first year of treatment, he said.
There is no subsidy for this drug, which costs $1,250 per injection.
Most patients are affected in both eyes, so the cost is doubled. They can use MediShield Life and Medisave to help pay for the treatment.
Prof Wong said that studies had shown that more than 150,000 people in Singapore have diabetic retinopathy but are unaware of it.
Diabetic macular edema is a subset of this, and is caused by the swelling of the macula, which is near the centre of the retina.
The earlier treatment starts, the better the prognosis, and the lower the cost.
Mr Loh Kok Kim, 54, noticed his eyesight getting worse about two to three years ago. But it was only last year, when spectacles could not improve his vision, that he consulted an eye doctor.
He started treatment on his left eye with Eyelea at the SNEC in July and said there is now less of a strain when he reads.
Mr Loh, who is a director of a construction firm, said each session, including doctor's fees, costs $1,650.
Medisave pays only $300. In spite of the high price, he said it was worth it as eyesight is very important, and he is now also getting his right eye treated.