Descriptive statistics of serum GFAP measurements (pg/mL) in patients without optic nerve disease1 are shown.

AQP4+ON patients showed the highest levels of serum GFAP as well as the highest variance. Both the median and mean values for serum GFAP level are higher in AQP4+ON patients compared to the values in the NMO spectrum group as a whole (4.63 pg/mL, 5.90 pg/mL). All values are stated to within 2 decimal places.1Std Dev = standard deviation.2C.I. = Confidence Interval.3ON = optic neuritis, AQP4+ON = Aquaporin 4 autoantibody positive ON, ‘CRION’ = ‘chronic relapsing inflammatory optic neuropathy’, ‘RION’ = Recurrent Isolated Optic Neuritis.