Importance: The Zika virus (ZIKV) might cause microcephaly and ophthalmoscopic findings in infants of mothers infected during pregnancy.

Objective: To assess and identify possible risk factors for ophthalmoscopic findings in infants born with microcephaly and a presumed clinical diagnosis of ZIKV intrauterine infection.

Design, setting, and participants: We conducted a cross-sectional study at the Altino Ventura Foundation in Recife, Brazil, that included 40 infants with microcephaly born in Pernambuco state, Brazil, between May and December 2015. Toxoplasmosis, rubella, cytomegalovirus, syphilis, and human immunodeficiency virus were ruled out in all of them. Testing of cerebrospinal fluid for ZIKV using IgM antibody-capture enzyme-linked immunosorbent assay was performed in 24 of 40 infants (60.0%). The infants and mothers underwent ocular examinations. The infants were divided into 2 groups, those with and without ophthalmoscopic alterations, for comparison.

Main outcomes and measures: Identification of risk factors for ophthalmoscopic findings in infants born with microcephaly and ZIKV intrauterine infection.

Results: Among the 40 infants, the mean (SD) age was 2.2 (1.2) months (range, 0.1-7.3 months). Of the 24 infants tested, 100% had positive results for ZIKV infection: 14 of 22 infants (63.6%) from the group with ophthalmoscopic findings and 10 of 18 infants (55.6%) from the group without ophthalmoscopic findings. The major symptoms reported in both groups were rash by 26 mothers (65.0%), fever by 9 mothers (22.5%), headache by 9 mothers (22.5%), and arthralgia by 8 mothers (20.0%). No mothers reported conjunctivitis or other ocular symptoms during pregnancy or presented signs of uveitis at the time of examination. Thirty-seven eyes (46.3%) of 22 infants (55.0%) had ophthalmoscopic alterations. Ten mothers (71.4%) of infants with ocular findings reported symptoms during the first trimester (frequency, 0.48; 95% CI, 0.02-0.67; P = .04). A difference was also observed between the groups of infants with and without ocular findings regarding the cephalic perimeter: mean (SD) of 28.8 (1.7) and 30.3 (1.5), respectively (frequency, -1.50; 95% CI, -2.56 to -0.51; P = .004).

Conclusions and relevance: Ocular involvement in infants with presumed ZIKV congenital infection were more often seen in infants with smaller cephalic diameter at birth and in infants whose mothers reported symptoms during the first trimester.