ORBITAL PAIN IN OPTIC NEURITIS AND ANTERIOR ISCHEMIC OPTIC NEUROPATHY

We analyzed the value of orbital pain in the differential diagnosis be tween optic neuritis (ON) and nonarteritic anterior ischemic optic neu ropathy (AION). A total of 99 consecutive patients with acute-onset op tic neuropathies formed the basis for this study. Compressive and vasc ulitic neuropathies were excluded. A total of 86 patients fulfilled th e criteria for inclusion into one of the following two groups, (I) ON (50 patients): less than or equal to 35 years, normal disc, recovery o f visual function in one month and (2) AION (36 patients): greater tha n or equal to 60 years, swelling of the disc, no recovery of visual fu nction in one month. Orbital pain was analyzed by asking patients stan dard questions and by having them rate the intensity of their pain on a visual analogue scale between 'no pain' and 'intolerable pain'. 74% of ON and 30% of AION patients reported spontaneous orbital pain. 92% of ON and 3% of AION patients reported orbital pain associated with ey e movements. On the visual analogue scale, ON patients rated their pai n as more severe than AION patients. We conclude that severe orbital p ain elicited or aggravated by eye movements strongly indicates ON rath er than AION.