Acute Optic Neuritis Classification

Acute Optic Neuritis

• Inflammation of the optic nerve

Classification

• Demyelinating: most common, associated with multiple sclerosis
• Para-infectious: occurs after viral infection or immunization
• Infectious: direct infection with Herpes Zoster or invading from surrounding orbit or brain
• Non-infectious: associated with sarcoidosis

Clinical Classification

• Papillitis: inflammation at the optic disc
• Retrobulbar neuritis: inflammation of the optic nerve behind the eye

Clinical Picture

Symptoms

• Acute painful loss of vision
• Pain exacerbated by adduction and elevation of the eye due to optic nerve sheath stretch

Signs

• Mild to severe visual loss (6/12 to PL)
• Impaired color vision
• Relative afferent pupillary defect (RAPD)
• Central and centrocecal scotoma for red and green

Fundus Picture

• Retrobulbar neuritis: normal fundus
• Papillitis:
  • Blurred disc margin and disc swelling
  • Obliteration of physiological cup
  • Disc hyperemia and splinter hemorrhage
  • Vitreous cells

Differential Diagnosis

• Papilloedema: usually bilateral, good V/A, severe disc swelling, enlarged blind spot, normal vitreous, normal pupil reaction
• Papillitis: usually unilateral, severe drop in vision, moderate disc swelling, central and centrocecal scotoma, vitreous opacities (cells), RAPD

Treatment

• Methylprednisolone (250 mg I.V every 6 hours for three days) followed by Prednisone tablets (1mg/Kg daily for 11 days)
• Multi-vitamins
• Interferon for resistant cases