CALIFORNIA, United States, Monday May 30, 2016 – Scientists studying the Zika outbreak are becoming increasingly concerned that the virus may cause eye damage in babies.
The virus is already known to cause microcephaly, in which infants are born with abnormally small heads and underdeveloped brains, as well as the rare neurological condition Guillain-Barre Syndrome in adults.
Previous research has found that one-third of Brazilian babies with microcephaly have eye problems such as ocular lesions, optic nerve abnormalities and chorioretinal atrophy, a withering of the retina and choroid, the latter of which provides oxygen and nutrients to the retina.
Now, the latest report on three Brazilian infants with microcephaly identified three new eye problems in the form of retinal lesions, bleeding in the retina and abnormal blood vessel development in the retina. The three infants also had the eye problems found in previous research.
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The latest vision findings, published in the journal Ophthalmology, add to a growing body of evidence about how Zika may affect children’s eye development and vision, the researchers said.
It’s not known if the virus itself causes eye problems or if the problems are a consequence of Zika-associated microcephaly.
“To my knowledge, the eye problems we found have not been associated with Zika virus before,” said study senior author Dr. Darius Moshfeghi, a professor of ophthalmology at the Stanford University School of Medicine, in Stanford, California.
“The next step is to differentiate what findings are related to the Zika virus itself versus microcephaly caused by the virus, in order to better understand which infants will need screening,” he said in a journal news release.
He added that some of the eye abnormalities would resolve or be treatable, but others could cause lasting, irreversible damage to vision.
The researchers said all babies with microcephaly in geographic areas affected by Zika should be examined by an ophthalmologist, advice that echoes screening recommendations from the US Centers for Disease Control and Prevention (CDC).
Such examinations “can contribute significantly to our understanding of the infection,” the study authors wrote.
Since last spring, Brazil has been the epicentre of a Zika outbreak, and nearly 5,000 babies have been diagnosed with microcephaly.
In the United States, a total of 279 Zika-infected pregnant women are being monitored, according to two registries that have been created by the CDC.
The virus is expected to become active in the United States in at least some Southern coastal areas this summer, as it typically passes from person to person via the bite of the Aedes aegypti mosquito, US health officials have said.
Zika is also known to be sexually transmitted.
More than 60 countries and territories, including the Caribbean and Latin America, now have continuing Zika transmission.