Zika Virus and Its Effects on Ocular Development Pre-Birth and Post-Birth Summary
The Zika virus has been reported in 86 countries worldwide. The symptoms of the virus are usually mild, including fevers, rashes and headaches. There is currently no treatment or vaccination available for infection by the virus. Those whose symptoms worsen should seek out medical advice and care right away. The primary transmission of the virus is through the bite of an infected mosquito, which bite during the day. However, there are other ways the virus can be passed, such as through blood transfusion and between mother and baby during pregnancy. When the virus is contracted during pregnancy, it can cause many birth defects in the baby, including microcephaly, which is a deformation of a baby’s head resulting in abnormally smaller head sizes. Various eye abnormalities may also occur.
It is known that the virus can lead to eye defects during congenital stages, but it has been unknown if it affects the eyes post-birth. A novel study from Glenn Yiu, an associate professor in the Department of Ophthalmology, discovered that during the first trimester of pregnancy, the Zika virus can affect fetal retinal development and cause ocular abnormalities from birth. In the study, two pregnant rhesus monkeys had contracted the Zika virus in their first trimester. The eye development of the babies who were exposed to the virus were studied for two years after birth. Rhesus monkeys have very similar eye characteristics to humans, including a macula, which makes them a better option to study the Zika infection rather than mice or rats.
The infants displayed many ocular birth defects pre-birth. One of these defects included big colobomas, which is when holes develop in the eye due to poor development. Furthermore, the baby monkeys also were missing photoreceptors, which are the light-sensing cells in the eye. Lastly, they also experienced loss of retinal ganglion neurons, which are neurons that help transfer important information to the brain from the retina. Although there were many defects pre-birth, the eyes seemed to develop normally post-birth, during the two years period.
This finding is very promising to the field of infections and diseases, as it furthers our understanding of the impacts of the Zika virus on babies prior to birth and post-birth. It suggests the idea that the ocular abnormalities of those infected by the Zika virus while in the womb seems to not occur after birth. Further research can be done to verify that this finding is true.