Drusen of the optic nerve head. An important model.

It is proposed that drusen of the optic nerve head (ONH) may provide a useful model for the study of diseases which affect the vicinity of the optic disc. Several sensitive and revealing tests of inner retinal/optic nerve function have been applied in this investigation. Fundus Photo Perimetry has confirmed that little correlation exists between visual field defects and the location of ophthalmoscopically visible ONH drusen. The Flashing Repeat Static Test (FRST) was found to be abnormal in half of our patients, indicating probable ascending dysfunction in optic nerve fibers beyond the lamina cribrosa. Alterations in transient-like and/or sustained-like functions, found in several cases, are thought to represent effects of dysfunction descending to the retinal plexiform layers.