Table 1.

Profiles of 18 patients with idiopathic ON, 18 patients with corticosteroid-associated ON, and 44 healthy controls. For qualitative variables, the number of patients is reported

Variable	Idiopathic ON	Corticosteroid-associated ON	Healthy controls
Sex
male	15	12	33
female	3	6	11
Age (years)
mean (SD)	45 (12)	41 (10)	45 (10)
median (range)	41 (27–74)	42 (25–64)	44 (22–64)
Bilaterality	9	9	–
Smoking habit
no. of smokers	13	7	42
no. of non-smokers	3	6	1
no. of unknown	2	5	1