The first sign of disc damage is usually an upper or lower temporal notch, giving rise to a nasal arcuate scotoma.
The extent of cupping is commonly assessed as the vertical cup:disc ratio, expressed as a fraction.
Characteristically, there is:
- right/left asymmetry
- cup to disc ratio is usually 0.5 or greater in the vertical plane
- affected area of disc is atrophic - light grey / white rather than pink
- the vessels may be angulated or kinked as they come over the rim of the cup - bayonetting
- vessels shifted to nasal edge of disc
- splinter haemorrhages at disc edge
Last reviewed 01/2018