Scarring the a detached retina

The Mueller cells (stained black) are the radial glia of the retina. One of these cells can be seen extending a process from the vitreal surface at the bottom of the picture through to a scarred area on the detached photoreceptor surface of the retina (top). The scar is formed by the enlargement of the glial cells. Scarring makes reattachment of the retina more difficult.