Illustration of tessellation in Down syndrome.

Background : Tessellated fundus refers to a specific change in the appearance of the internal layers of the eye in which the choroidal large vessels became visible through polygonal hypopigmented areas. Such hypopigmented areas alternate with hyperpigmented zones in a tigroid pattern. Fundus tessellation is often associated with myopia and choroidal thinning. Materials and Methods : We analyzed fundus images from 50 children with Down syndrome and 52 controls. Results : Tessellation was present in 64% of children with Down syndrome, compared with only 13.5% of controls ( p < .0001). In most cases, tessellation was located peripapillary, and no difference was observed in tessellation localization between children with Down syndrome and controls ( p = .60). Although more prevalent in myopic children with and without Down syndrome, tessellation was present in almost half (48%) of children with Down syndrome with hyperopia versus only 5% of controls with the same refractive status. Conclusions : Mechanical stretching of the choroid could explain the high rate of tessellation in myopes. Other factors must contribute to the higher prevalence of tessellated fundus in children with Down syndrome without myopia. We discuss potentially relevant factors and propose vascular involvement as a contributor to tessellation in our population with Down syndrome. Further studies assessing choroidal vasculature in individuals with Down syndrome are needed to confirm this theory.