The optic nerve enters through the back of the eye. Once inside, the nerve fibers spread out across the retinal surface in all directions. When the nerves fan out, there is a small depression in the center of the visible optic nerve called the “cup.” Interestingly, the blood vessels that nourish the retina come into the eye along with the optic nerve. These blood vessels also fan out in all directions across the retinal surface. On the left is a photo of the optic nerve as your doctor sees it when he examines your eyes. On the right is a schematic cross section. The optic nerve connects the eye to the brain, much like a cable connects your computer to your monitor.
This Nerve Fiber Layer (RNFL) can be measured with our Optical Coherence Tomographer (OCT) instrument. The results are displayed in a graphical representation of the thickness (and health) of the nerve fiber layer. Here is an example of the analysis rreport from an OCT scan (normal right eye on top, abnormal left eye with thinning on the bottom). Optic nerve analysis is especially important in glaucoma.