An 11-year-old girl presented with a decrease in the vision of her left eye. Her visual acuity was 20/60 OS. The left eye fundus results showed retinal arteriovenous malformations with markedly convoluted, dilated, and tortuous retinal vessels extending from the disc (Figure).
On optical coherence tomography angiography, the foveal avascular zone could not be identified because of the anomalous vessel, and capillary nonperfusion areas were not evident. The anomalous vessels, especially on the superficial retinal vascular segment, had high flow. No intracranial arteriovenous malformations were detected with magnetic resonance imaging. Wyburn-Mason syndrome is a rare nonhereditary disorder in which vascular dysgenesis affects the retina and brain.