Optic nerve |
I No optic nerve invasion |
II Optic nerve invasion not beyond the lamina cribrosa |
III Invasion beyond the lamina cribrosa but not up to surgical resection line |
IV Invasion up to the surgical resection line or presence of neoplastic cells in the subarachnoid space |
Ocular coats |
I No involvement |
II Focal choroidal invasion (up to three small groups of neoplastic cells) |
III Massive choroidal invasion (defined as any invasion greater than focal with no scleral invasion) |
IV Partial scleral invasion |
V Total thickness scleral invasion or tumour cells in the peribulbar tissue |