Perioptic meningiomas. Syndrome of long-standing visual loss, pale disk edema, and optociliary veins.

Three patients had a syndrome of progressive or long-standing visual loss, pale disk edema, and optociliary veins, indicating that a spheno-orbital meningioma had invaded the anterior perioptic meninges. To diagnose this syndrome, one must distinguish "disk edema" from "papilledema"; although both result from increased pressure within the perioptic subarachnoid space, disk edema is caused by a variety of lesions just behind the globe, whereas papilledema is caused by remote lesions that raise intracranial pressure. Optociliary veins reflect the slowness of progression of both processes. This ophthalmoscopic diagnosis carries important implications, namely, that the tumor grows very slowly and that surgical treatment will not improve vision. Therefore, excision may not be the treatment of choice.