Ocular Histopathologic Features of Congenital Zika Syndrome

Congenital Zika syndrome (CZS) is known to be associated with severe malformations in newborns. Although microcephaly is the hallmark of this disease, the ocular findings are important given the severe visual impairment that has been observed in these patients. Regardless of the increased number of CZS cases reported, to date, no studies have described the ocular histopathologic findings of this entity.

To evaluate the presence of Zika virus (ZIKV) antigens and describe the associated ocular histopathologic features of 4 cases of CZS.

In this observational case series performed from June 19, 2015, through April 30, 2017, ocular tissue samples from 4 deceased fetuses with a diagnosis of CZS from the National Institute of Health in Colombia were sent to the Florida Lions Ocular Pathology Laboratory for evaluation.

The microscopic features of each specimen were described, and immunostaining was performed using a ZIKV NS2B protein antibody.

Ocular tissue samples from the 4 deceased fetuses (2 female, 2 male) ranging from 21.5 to 29 weeks' gestation with a diagnosis of CZS were studied. The 4 eyes manifested with pupillary membranes, immature anterior chamber angles, loss of pigment and thinning of the retinal pigment epithelium, choroidal thinning, undifferentiated nuclear layers of the retina, and a perivascular inflammatory infiltrate within the choroid. The optic nerve, present in 2 of the eyes, demonstrated atrophy. Expression of ZIKV antigen was present in the iris in cases 1, 3, and 4; the neural retina and choroid in case 1; and in the optic nerve in case 4.

Loss of retinal pigment epithelium, the presence of a thin choroid, a perivascular choroidal inflammatory infiltrate, and atrophic changes within the optic nerve were consistently present. These findings may be attributed to ZIKV infection and warrant further study.