Scientists have shown that they can test for the SARS coronavirus by using a patients tear drops.
A team of ophthalmologists, virologists and infectious disease specialists from the National University Hospital, Singapore, Tan Tock Seng Hospital and Singapore General Hospital made their discovery working with teardrops taken from 36 patients in April last year. All of the 36 were suspected of having SARS.
Eight patients were eventually confirmed as having contracted the SARS and the actual virus was found in the teardrops of three of them. The detection method was based upon similar technology used to detect the virus in blood and stool samples.
Scientists believe that the timing of the tear drop sampling is crucial in obtaining valid results. The samples from three patients who tested positive were taken within nine days after fever started, the teardrops of the other patients who tested negative were collected after 9 days.
The research leader, Loon Seng Chee said: 'We were surprised to find that tests on one patient's tears picked up the virus at an early stage, while tests of her blood and other fluids could not. So this could become important in diagnosing SARS in the future.'
Getting a suspected patient's tears would be more convenient than getting a blood or stool sample as it is painless, can be taken at any time and more tears can be collected easily, added the associate consultant ophthalmologist at The Eye Institute, which oversees the eye departments of TTSH and NUH.