Table 3.

Clinical classifications of papilloedema.

Vascular changes (based on Hoyt and Beeston classification)28,29	Nerve fibre layer changes (modified Frisén scale)*30
Early : hyperaemia	Stage 0: normal optic disc Prominence of the retinal nerve fibre layer at the nasal, superior, and inferior poles in inverse proportion to disc diameter. Radial nerve fibre layer striations, without tortuosity.
Acute : haemorrhages, exudates and small infarcts of peripapillary nerve fibre layer (cotton-wool spots)	Stage 1 : minimal degree of oedema C-shaped halo that is subtle and greyish with a temporal gap; obscures underlying retinal detailsa Disruption of normal radial nerve fibre layer arrangement striations Temporal disc margin normal
Chronic : no haemorrhages or exudates; vessels undergo structural changes such as telangiectasias and retinochoroidal collaterals, punctate white glistening dots on the disc that may be a manifestation of long-standing neurodegeneration	Stage 2 : low degree of oedema Circumferential haloa Elevation (nasal border) No major vessel obscuration
	Stage 3 : moderate degree of oedema Obscuration of ≥ 1 segment of major blood vessels leaving disca Circumferential halo Elevation (all borders) Halo (irregular outer fringe with finger-like extensions)
Atrophic : pallid and flat disc	Stage 4 : marked degree of oedema Total obscuration on the disc of a segment of a major blood vessel on the disca Elevation (whole nerve head, including the cup) Border obscuration (complete) Halo (complete)
	Stage 5 : severe degree of oedema Obscuration of all vessels on the disc and leaving the disca

*Note that the modified Frisén scale does not include secondary optic atrophy.

^aKey feature (major findings) for each grade.