Zika: Check All Potentially Exposed Infants for Eye Damage

Marcia Frellick

July 17, 2017

All infants with possible maternal Zika virus exposure should undergo eye exams regardless of timing of exposure, laboratory confirmation, or whether they have central nervous system abnormalities, new research suggests.

Eye abnormalities may be the only initial sign of congenital Zika virus infection, which is important because some guidelines recommend eye exams only if babies have microcephaly or laboratory confirmation of the virus.

Andrea A. Zin, MD, PhD, from the Departamento de Pesquisa Clinica, Instituto Nacional de Saúde da Mulher, Rio de Janeiro, Brazil, and colleagues report their findings in an article published online July 17 in JAMA Pediatrics.

The researchers evaluated infants whose mothers had Zika virus infection, confirmed by reverse transcription polymerase chain reaction, from January through October 2016. A team including a pediatric ophthalmologist examined the infants until age 1 year.

Of 112 infants, 24 (21.4%) had sight-threatening eye abnormalities (median age at first eye examination, 31 days; range, 0 - 305 days). The most common were optic nerve and retinal abnormalities. Ten infants with eye abnormalities (41.7%) did not have microcephaly, and eight (33.3%) did not have any central nervous system (CNS) abnormalities.

Eye abnormalities were more common when mothers were infected during the first trimester, but they could occur with infection at any time during the pregnancy. Fourteen babies with eye abnormalities (58.3%) were born to women infected during the first trimester, eight (33.3%) during the second, and two (8.3%) during the third.

Eye abnormalities were much more likely in those with microcephaly (odds ratio [OR], 19.1; 95% confidence interval [CI], 6.0 - 61.0), other CNS abnormalities (OR, 4.3; 95% CI, 1.6 - 11.2), and arthrogryposis (OR, 29.0; 95% CI, 3.3 -2 55.8).

The study was performed at the Fernandes Figueira Institute, Oswaldo Cruz Foundation in Rio de Janeiro, a referral site for women with high-risk pregnancies and children with infectious diseases.

This research, as well as previous research, has found that eye abnormalities occur not only in infants with microcephaly, which is important because the Brazilian Ministry of Health guidelines recommend screening eye exams for infants born in Zika-endemic areas only if there is microcephaly.

When eye abnormalities were first reported in cases where an infant had microcephaly and presumed Zika infection, it was unclear whether the eye abnormalities were secondary to microcephaly or whether they were directly linked to Zika, the authors note.

This study reports "that 10 of 24 eye abnormalities (41.7%) occurred in the absence of microcephaly in RT-PCR-confirmed cases of Zika virus infection. Thus, it seems that Zika virus can be deemed to be directly related to eye pathologic findings."

The researchers also found that eye findings were present even in infants without CNS abnormalities.

"If the presence of CNS abnormalities were used as screening criteria for eye examination in our population, 3 infants with abnormal eye examination findings would have been missed," they write.

Centers for Disease Control and Prevention guidelines recommend eye screening only if a laboratory confirms a congenital Zika infection. Because those tests are not always available, eye abnormalities may be missed, the authors explain.

Limitations include a bias for microcephaly and other characteristics of Zika, as the site studied was a referral site. The study also included no control group.

The authors acknowledge they "cannot affirm with absolute certainty" that all eye findings were linked to Zika.

This study was supported by the Brazilian National Council for Scientific and Technological Development, the National Institute of Allergy and Infectious Diseases, and the National Eye Institute. A coauthor was supported in part by an unrestricted Research to Prevent Blindness grant given to the Stein Eye Institute. Another coauthor was supported in part by the Thrasher Research Fund. The authors have disclosed no relevant financial relationships.

JAMA Pediatr. Published online July 17, 2017. Article

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