Table 3.

Features of Atypical ON in Adults

• Age > 50 or < 12 years [2,9]

• Simultaneous or sequential bilateral ON [2,4,9]

• light perception) which progress for > 2 weeks from onset [1,2,4,9]

• Painless/painful/persistent pain > 2 weeks [2,4,9]

• Abnormal ocular findings: Noticeable anterior and/or posterior segment inflammation [2] Significant uveitis [9] and retinal periphlebitis [2,9] Intensely swollen optic nerve head [2,4,9] Severe optic disc haemorrhages [1,2,5,9] Retinal exudates [1,4,5] Macular star [1]

• Absence of any visual recovery within 3-5 weeks [2,4,9] or continued exacerbation in visual function [2]

• Lower risk of developing MS [4]

• Manifestation of systemic diseases other than MS [2,9]

• Deterioration in vision after steroids discontinuation [2,9]

• Family history [2]

• Previous history of neoplasia [2,9]

• Optic atrophy lacking history of ON or MS [9]