Study finds optic nerve pallor prevalent in patients with Zika virus

A study of the ocular findings in infants with congenital Zika virus syndrome (CZS) showed that the findings were similar and occurred frequently among the affected infants.

The most prevalent of the findings was optic nerve pallor, according to Denise Freitas, MD, who is from the Department of Ophthalmology and Visual Sciences at the Paulista School of Medicine, Hospital São Paulo, and the Federal University of São Paulo in Brazil.

Freitas and colleagues conducted a study to characterize the ocular findings in infants with microcephaly and CZS from 2015 to 2017 in Paraíba, Brazil. The investigators classified the infants into 1 of the following 3 categories: confirmed congenital ZIKV infection based on a positive test and negative for rubella, toxoplasmosis, human immunodeficiency virus, syphilis, cytomegalovirus, and herpes simplex virus; probable congenital ZIKV infection, indicating a previous ZIKV infection or passive immunity and negative tests for the other infections; or suspected ZIKV infection in infants who did not undergo testing for ZIKV or other diseases but exhibited clinical findings suggestive of the congenital ZIKV syndrome, Freitas explained.

Findings in study infants
Fifty-six infants were included in the study, all of whom had microcephaly and other signs that are typical of CZS. The mean age at examination was 5.25 months (median, 4 months; range, 1-12 months). The mean head circumference was 28.76 cm (median, 29 cm; range, 25.0-31.9 cm).

Freitas explained that 12 (21.4%) infants had confirmed congenital ZIKV infection, 15 (26.8%) had probable infection, and 29 (51.8%) had suspected infection. Ocular findings were identified in 24 (42.9%) of the 56 infants and included gross retinal pigmentation in 11 (45.8%), macular chorioretinal atrophy in 11 (45.8%), optic nerve hypoplasia in 1 (4.2%), optic nerve pallor in 14 (58.3%), and increased optic disc excavation in 2 (8.3%).

“The ocular findings were similar among the infants and consistent with those reported in the literature, regardless of the patients’ serologic confirmation or classification,” Freitas said. “The findings were identified frequently and the prevalent was optic nerve pallor.”