Zika may severly damage infant's retina: study

Zika virus can cause severe damage to retina in infants and lead to visual impairments, a new study has warned.
Researchers from Federal University of Sao Paulo in Brazil examined the affected retinal layers in infants with congenital Zika syndrome and associated retinal abnormalities using optical coherence tomography (OCT) - a noninvasive diagnostic imaging tool that provides cross-sectional retinal images.
The study included eight infants of age three to five months with congenital Zika syndrome (CZS), the term used for a variety of anomalies associated with intrauterine Zika virus infection.
OCT images were obtained in the affected eyes of seven infants with CZS who had undergone previous ophthalmologic examinations.

An immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay for Zika virus was performed on the cerebrospinal fluid samples of seven of the eight infants, and other congenital infections were ruled out, researchers said.
Among the eight infants included in the study, seven who underwent cerebrospinal fluid analysis for Zika virus had positive findings for IgM antibodies.

Eleven of the 16 eyes (69 per cent) of the eight infants had retinal alterations and OCT imaging was performed in nine (82 per cent) of them.
Optical coherence tomography was also performed in one unaffected eye.
The main OCT findings included the abnormalities of severe neurosensory retinal thinning with discontinuation of the ellipsoid zone associated with choroidal thinning, and a hyperreflectivity underlying the atrophic retinal pigment epithelium.

"The use of OCT technology in this case series showed severe involvement of the neurosensory retina, including the internal and external layers, and the choroid," researchers said.
"Although these findings provide important new information about this devastating disease, they are not unique to CZS, and therefore OCT cannot be used to differentiate CZS from other retinal diseases," they said.
The study appears in the journal JAMA Ophthalmology.