The eyes are the windows to
the soul and, apparently, infections of the body too.
Analyzing tears could jump-start detection of the virus
that causes severe acute respiratory syndrome (SARS),
according to a report in the July issue of the British
Journal of Ophthalmology.
Researchers, headed by Dr Seng
Chee Loon of Tan Seng Hospital in Singapore, took swabs
of the eye surfaces from 36 patients suspected of having
SARS. The resulting samples were checked for SARS virus
DNA -- other eye infections have been unearthed in this
way.
Three patients who were sampled
early in the course of their infection tested positive
for the virus, according to researchers. "This is the
first case series reported with the detection of the
SARS coronavirus from tears," wrote the authors.
Conversely, the virus wasn't found
in tears of patients whose illness was further along.
According to Dr Loon, this may be because the virus
is secreted in tears only at the onset of the disease.
However, "more studies must be carried out to determine
this -- hopefully NOT during another epidemic," said
co-author Dr Steven Teoh.
"What they describe will not appreciably
alter our ability to diagnose SARS earlier," said Dr
Susan Richardson, head of the division of microbiology
at The Hospital for Sick Children in Toronto. "The patients
who had positive results were up to nine days after
illness onset. This is not early -- early in my books
is within the first three days."
Dr Richardson felt that the presence
of the virus in the eye fluid was likely due to chance
contamination from the respiratory tract. "Without viral
replication in the eye, it's unlikely that detection
of the virus will be very successful from this site
as compared to either the respiratory tract or stool."
Dr Loon acknowledged that it's
early days yet. "Indeed, the sample is small and we
cannot draw too many conclusions," he said. "The paper
is meant to highlight the existence of the virus in
tears ... and a possible tool to screen future cases."
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