Primary optic neuropathy in Behçet's syndrome.

Background: Primary optic neuropathy in Behcet's syndrome (PONBS) is limited to a few case reports. Objective: To investigate the clinical features, magnetic resonance imaging (MRI) changes, and visual prognosis of PONBS. Methods: Sixty-one patients who presented with first onset of optic neuritis and fulfilled the International Criteria for Behcet's Disease (ICBD) were evaluated. Results: The female-to-male ratio was 1.7:1. No patient had other central nervous system (CNS) disease. In 67 eyes with optic nerve abnormalities on MRI scan, perineural enhancement around the orbital optic nerve (46 eyes, 68.7%) was significantly more frequent than was increased signal in the optic nerve itself (31 eyes, 46.3%; p = 0.000), typically with sunflower-like appearance on coronal view (33 eyes, 71.7%). Two patients (3.6%) relapsed during follow-up (median 12 months). Kaplan-Meier survival analysis estimated the cumulative risk of severe visual loss (<= 0.1) at 24 months was 14.7% in females versus 62.5% in males (hazard ratio (HR), 0.16; 95% confidence interval, 0.05-0.54). Conclusion: PONBS frequently presents with isolated optic neuropathy in females. The sunflower-like sign might be a distinctive MRI feature. Short-term recurrence is very rare. Males have a higher cumulative risk of severe visual loss.