Abstract
Knowledge regarding the frequency of ocular abnormalities and abnormal visual function in children exposed to Zika virus (ZIKV) in utero but born without congenital Zika syndrome (CZS) is limited. We hypothesized that children exposed to ZIKV in utero born without CZS may have visual impairments in early childhood. We performed ophthalmic examination between 16 and 21 months of age and neurodevelopment assessment at 24 months of age with the Mullen Scales of Early Learning test (MSEL) on children enrolled in a cohort born to women pregnant during and shortly after the ZIKV epidemic in Nicaragua (2016-2017). ZIKV exposure status was defined based on maternal and infant serological testing. Visual impairment was defined as abnormal if the child had an abnormal ophthalmic exam and/or low visual reception score in the MSEL assessment. Of 124 children included in the analysis, 24 (19.4%) were classified as ZIKV-exposed and 100 (80.6%) unexposed according to maternal or cord blood serology. Ophthalmic examination showed that visual acuity did not differ significantly between groups, thus, 17.4% of ZIKV-exposed and 5.2% of unexposed had abnormal visual function (p = 0.07) and 12.5% of the ZIKV-exposed and 2% of the unexposed had abnormal contrast testing (p = 0.05). Low MSEL visual reception score was 3.2-fold higher in ZIKV-exposed than unexposed children, but not statistically significant (OR 3.2, CI: 0.8-14.0; p = 0.10). Visual impairment (a composite measure of visual function or low MESL visual reception score) was present in more ZIKV-exposed than in unexposed children (OR 3.7, CI: 1.2, 11.0; p = 0.02). However, the limited sample size warrants future investigations to fully assess the impact of in utero ZIKV exposure on ocular structures and visual function in early childhood, even in apparently healthy children.