Papilledema refers to optic disc edema occurring secondary to raised intracranial pressure. In patients with intracranial tumours, tumour size might be the expected predictor of whether or not papilledema will develop, however, this is not the case in clinical practice. We report a series of 5 patients with large intracranial tumours and no evidence of papilledema and discuss the potential factors which may contribute to the lack of optic disc edema in these cases. Development of papilledema depends on both the presence of elevated intracranial pressure and transmission of elevated pressure to the subarachnoid space within the optic nerve sheath and to the optic nerve itself. We discuss how intracranial tumours may influence the physiology of the surrounding tissues, cerebrospinal fluid dynamics and cerebral venous outflow and how individual anatomic variations, particularly within the optic nerve sheath and optic canal, likely play a role in development of papilledema.

视乳头水肿是指继发于颅内压升高的视盘水肿。在颅内肿瘤患者中，肿瘤大小可能是是否会发生视乳头水肿的预期预测因素，但在临床实践中并非如此。我们报告了一系列 5 例颅内大肿瘤且无视乳头水肿证据的患者，并讨论了在这些病例中可能导致视盘水肿不足的潜在因素。视乳头水肿的发展取决于颅内压升高和升高的压力传递到视神经鞘内的蛛网膜下腔和视神经本身。我们讨论颅内肿瘤如何影响周围组织的生理，