While they may look like the delicately twisting veins of a leaf, these are veins of a different kind. They're the blood vessels in the retina – the structure at the back of the eye packed with light-sensing cells that enable us to see. This picture was created using scanning laser ophthalmoscopy, where a fluorescent dye is injected into the bloodstream. Eventually it reaches the tiny vessels in the retina, where it glows under blue laser light. Some of the tiny vessels in the centre of this image are leaking, showing up as fuzzy bright regions against the neat network. In patients with a condition known as central serous chorioretinopathy, this leaked fluid builds up in small pools under the retina – much like a blister under the skin – causing sight problems. Techniques like this are vital for diagnosing the problem, and seeing how it respond to treatment.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.