Zika virus affects eye development before but not after birth – ScienceDaily

While the SARS-CoV-2 virus has made a big impact on the news this year, researchers are still studying the health effects of the Zika virus, which has been reported in 86 countries around the world.

The Zika virus is mainly transmitted by an infectious mosquito bite from the genus Aedes. However, it can also go through sexual intercourse, blood transfusion, organ transplants, and between mother and baby during pregnancy. The virus has been documented to cause a range of birth defects, including microcephaly and a number of brain, muscular, and ocular disorders.

A new study from Glenn Yiu, an associate professor in the Department of Ophthalmology, and Koen Van Rompay, a senior scientist at California’s National Primacy Research Center, found that Zika disease during the first trimester of pregnancy can affect development fetal retinal and congenital ocular abnormalities. The virus does not appear to affect ocular growth postnatally, however.

“It is known that sexually transmitted infections with the Zika virus can lead to eye defects, but it was unclear whether the virus continues to reproduce or affect eye development after birth,” Yiu said. . “Our study in rhesus monkeys suggests that the virus significantly affects fetal development during pregnancy, but not on eye growth after birth.”

In this collaboration between the UC Davis Eye Center and the California National Primacy Research Center, two rhesus monkeys pregnant with Zika virus were diagnosed late in the first trimester. The ocular development of infants exposed to Zika was then studied for two years after birth.

Ocular birth problems

The baby monkeys exposed to Zika did not appear to show microbial or behavioral deficiencies. But the babies had several ocular birth defects. The defects included large colobomas, a gap that was missing in the eye due to excessive development. The baby monkeys exposed to Zika also showed a loss of photoreceptors – retinal light sensory cells – and retinal ganglion neuron, which help transmit visual information to the brain.

Despite congenital ocular malformations at birth, their eyes appeared to follow normal development in their first two years.

The findings suggest that ocular deficits due to Zika disease occur mainly in utero and may not have a lasting effect on postpartum ocular development.

Rhesus macaques are natural hosts of the virus and share human-like immune and ocular properties, including blood-retinal barrier properties and the specific presence of macula, making them better animal models of the disease than typical laboratory animals such as mice and rats. The results were published in JCI Vision, a peer-reviewed open journal dedicated to biochemical research.

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Materials provided by University of California – Davis. Original writing by Lisa Howard. Note: Content can be edited for style and length.