Epidemiology

  • Incidence: 7.00 cases per 100,000 person-years
  • Peak incidence: 30-40 years
  • Sex ratio: more common in females 2:1
<1 1-5 6+ 16+ 30+ 40+ 50+ 60+ 70+ 80+

Clinical features

Symptoms
Signs
  • Optic atrophy (3%): This is a late sign that is not usually found on initial presentation