Congenital Zika, Cobalamin C Deficiency: Retinal Changes Evaluated With SD-OCT

HealthDay News — Retinal maldevelopment associated with congenital Zika syndrome (CZS) is similar to the maldevelopment seen with cobalamin C (cblC) deficiency, according to a study published in JAMA Opthalmology.

Tomas S. Aleman, MD, from the University of Pennsylvania in Philadelphia, and colleagues quantified the microstructural changes of the retina in 8 infants with CZS and compared these changes to those associated with cblC deficiency in 8 children.

The researchers found that all 8 patients with CZS had foveal abnormalities in the analyzed eyes (8 eyes), including discontinuities of the ellipsoid zone, thinning of the central retina with increased backscatter, and severe structural disorganization. 

Three eyes showed macular pseudocolobomas. In 7 of 8 eyes with a normal photoreceptor layer, pericentral retina with normal lamination showed a thinned (<30% of normal thickness) ganglion cell layer (GCL) that colocalized. The inner nuclear layer was normal or had borderline thinning. The central retinal degeneration was similar to that of cblC deficiency.

“The findings provide the first, to date, in vivo evidence in humans for possible retinal maldevelopment with a predilection for retinal GCL loss in CZS, consistent with a murine model of the disease and suggestive of in utero depletion of this neuronal population as a consequence of Zika virus infection,” conclude the authors.

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Aleman TS, Ventura CV, Cavalcanti MM, et al. Quantitative assessment of microstructural changes of the retina in infants with congenital Zika syndrome [published online September 7, 2017]. JAMA Opthalmol. doi: 10.1001/jamaophthalmol.2017.3292