Supranumerary optic disc vessels may indicate reduced systemic angiogenesis in Down syndrome

A markedly increased number of retinal blood vessels at the level of the optic disc is often present in Down syndrome.1 Additional characteristics of trisomy 21 include a low incidence of proliferative changes in those with longstanding diabetic retinopathy2 and a markedly low incidence of solid cancerous growth.3 A mechanism is proposed to link these and other findings. Angiogenesis, as opposed to vasculogenesis (the de novo formation of vessels via differentiation of endothelial precursor cells), consists of new vessel formation by budding off from existing vessels.4 5 During embryogenesis this occurs mainly in the eye and in the kidney.5 6 …