The histology of retinal nerve fiber layer bundles and bundle defects
R. L. Radius and D. R. Anderson
The fiber bundle striations recognized clinically in normal monkey eyes
appear to be bundles of axons compartmentalized within glial tunnels formed
by Muller's-cell processes, when viewed histologically. The dark boundaries
that separate individual bundles are the broadened foot endings of these
cells near the inner surface of the retina. Within one week after focal
retinal photocoagulation, characteristic fundus changes could be seen in
experimental eyes. In histologic sections of the involved retina, there was
marked cystic degeneration of the retinal nerve fiber layer. Within one
month, atrophy of distal axon segments was complete. With the drop-out of
damaged axons and thinning of individual fiber bundles, retinal striations
became less prominent. The resulting fundus picture in these experimental
eyes is similar to fiber bundle defects that can be seen clinically in
various neuro-ophthalmic disorders.
