Optic perineuritis not associated with syphilitic infection

Optic perineuritis is a rare syndrome characterized by bilateral, sometimes unilateral, optic disc swelling without a raised cere brospinal fluid (CSF ) pressure and visual dysfunction except for big blind spots, which are pre sumed to be an inflammation of the optic nerve sheaths. Syphilitic infectio n is known to be most commonly associated with optic perineuritis, We prese nt three cases of optic perineuritis without syphilitic infection. Two of t hem showed disc swelling and blind spot enlargement bilaterally, which subs ided in a good response to the corticosteroid therapy. In the remaining one case, the left eye exhibited disc swelling without visual disturbance as i n the other cases, while anterior ischemic optic neuropathy occurred and pr oduced the permanent visual field defect in the right eye, presumably due t o the coincidental existence of optic disc hypoplasia. CSF in all cases sho wed normal pressure and lymphocytosis, which faded in response to the corti costeroid therapy. A lumbar puncture was a critical maneuver for the correc t. diagnosis, Despite the overall favorable outcome, immediate treatment sh ould be considered for optic perineuritis patients, especially those who ha ve a local anatomical vulnerability of the disc.