Researchers from Brazil evaluated the use of optical coherence tomography to assess the impact of congenital Zika virus infection on infants’ eyes.
Zika virus has been shown to cause significant retinal damage to many of those infected—and now researchers have a better idea of how to identify and assess its effects.
In a study published in the December issue of JAMA Ophthalmology, ophthalmologists from the Altino Ventura Foundation and Pernambuco Eye Hospital (both in Recife, Brazil), the Paulista School of Medicine at Federal University in São Paulo, and the Bascom Palmer Eye Institute in Miami, as well as a pediatric neurologist from Barão de Lucena Hospital (also in Recife) sought to assess the value of optical coherence tomography (OCT) evaluation as a tool in measuring the impact of the mosquito-borne virus on the eyes of infants with congenital Zika syndrome. OCT is a tool used by eye care professionals worldwide to assess mostly adult patients for various ocular diseases, including cataracts and glaucoma.
For their cross-sectional, consecutive case series, the authors evaluated 8 infants (3 males and 5 females, ranging in age from 3 months to 5 months) with congenital Zika syndrome. They obtained OCT images from the eyes of all 8 infants, after confirming Zika virus infection via IgM antibody-capture enzyme-linked immunosorbent assay. They found that 11 of the 16 eyes (69%) had retinal alterations, and performed OCT in 9 of the affected eyes and 1 unaffected eye.
According to their published report, OCT findings in the affected eyes included “discontinuation of the ellipsoid zone and hyperreflectivity underlying the retinal pigment epithelium, retinal thinning (8 eyes), choroidal thinning (7 eyes), and colobomatous-like excavation involving the neurosensory retina, retinal pigment epithelium, and choroid (4 eyes).”
“Despite predicting severe damage to the retina only by observing the fundus of these babies, we could not tell precisely which layers of the retina were injured by the infection,” study lead author Camila V. Ventura, MD, told Contagion. “This study used OCT to analyze the retinal layers and it showed that depending on the severity of the lesions, we can observe damage to the outer retina alone or in more severe cases, all retinal layers are affected. However, since the outer retinal layers are affected in all cases that presented a chorioretinal scar, we can probably predict significant visual loss in all cases.”
However, in spite of the device’s efficacy in assessing Zika-related ocular damage, Dr. Ventura and her colleagues acknowledge that it may not be the most practical tool for use in affected infants, due to its limitations and the fact that findings cannot be used in diagnosis. Still, the researchers believe OCT can play a vital role in helping them “analyze retinal tissue… to clarify the precise cause and pathophysiology of lesions… and [ultimately] correlate these findings with visual acuity and function,” she said.
“To perform OCT in babies, ideally you need a portable OCT in order to image the baby in a more physiological and comfortable position, such as lying down,” Dr. Ventura added. “These portable OCTs are not commonly found in clinics and the traditional OCTs that are more commonly found require a bigger team effort to synchronize holding the baby still and capturing the images.”
Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.