The honeycomb-like appearance of the retinal pigment epithelium
This confocal microscope image shows the cells of the retinal pigment epithelium (RPE), a layer in the back of the eye behind the retina. Fluorescent probes have been used to tag the nuclei of the cells (blue) and the actin cytoskeleton (green), which helps maintain cell structure. The orderly packing of these cells gives the RPE its characteristic honeycomb-like appearance.
The RPE plays a vital role in the vision process by nourishing photoreceptor cells, which respond to light, and by regenerating visual pigments, which detect light that strikes the retina.
Degenerative changes in the RPE cell layer can occur in some forms of age-related macular degeneration and in many other eye diseases. These changes may cause severe visual impairment.
Image of bovine eye tissue, courtesy of Robert N. Fariss, Ph.D., National Eye Institute Biological Imaging Core