Early postoperative sterile hypopyons.

1977a). Neither of these assertions, however, is based on -definite evidence. The relevance, for example, of the observation (Hayreh, 1976, 1977b) that fluorescein can diffuse from the cistema magna to the vitreous cavity via the -subarachnoid space, optic nerve, and optic disc is unclear. The prelaminar venular congestion mentioned by Mr Primrose was observed to be a late event during the development of experimental papilloedema (Hayreh and Hayreh, 1977b). Nevertheless, this in no way detracts from the possibility that an ischaemic mechanism may be operating in the retrolaminar ciliary artery territory (as postulated, though unsubstantiated, by Mr Primrose) and may be contributing to the axoplasmic transport block in papilloedema. DAVID MCLEOD