Zika virus may cause eye abnormalities in infants: Study

WASHINGTON: Vision-threatening eye abnormalities in infants with microcephaly - a birth defect characterised by an abnormally small head - may be associated with presumed intrauterine infection with Zika virus, a new study has warned.

An epidemic of Zika virus has been happening in Brazil since April 2015. Six months after the onset of the Zika virus outbreak, there was an unusual increase in newborns with microcephaly.

In January this year, the Brazilian Ministry of Health reported 3,174 newborns with microcephaly.

Researchers from Federal University of Sao Paulo in Brazil evaluated the ocular findings of 29 infants with microcephaly (head circumference less than or equal to 32 centimetres) with a presumed diagnosis of congenital Zika virus.

Of the 29 mothers, 23 (79.3 per cent) reported suspected Zika virus signs and symptoms during pregnancy, including rash, fever, arthralgia (joint pain), headache and itch.

Among the 23 mothers who reported symptoms during pregnancy, 18 or 78.3 per cent reported Zika virus symptoms during the first trimester of pregnancy, researchers said.

Abnormalities of the eye were observed in 10 of the 29 infants (34.5 per cent) with microcephaly; of the 20 eyes in 10 children, 17 eyes (85 per cent) had ophthalmoscopic abnormalities.

Bilateral abnormalities were found in 7 of the 10 infants (70 per cent) presenting with ocular lesions, the most common of which were focal pigment mottling of the retina and chorioretinal atrophy in 11 of the 17 eyes with abnormalities (64.7 per cent).

There also were optical nerve abnormalities in eight eyes (47.1 per cent), along with other findings.

"Infants with microcephaly should undergo routine ophthalmologic evaluations to identify such lesions. In high-transmission settings, such as South America, Central America and the Caribbean, ophthalmologists should be aware of the risk of congenital ZIKV-associated ophthalmologic sequelae," researchers said.

The findings were published in the journal JAMA Ophthalmology.