Neuromyelitis optica or multiple sclerosis?

To identify factors associated with subsequent development of neuromyelitis optica (NMO) after a first-ever optic neuritis (ON) attack, investigators compared ophthalmic and MRI findings of NMO and multiple sclerosis (MS) patients who first presented with ON.

They found that severe optic nerve damage at the first ON attack was associated with subsequent development of NMO, whereas presence of brain abnormalities was associated with developing MS (P = 0.001).

Additionally, they found that NMO patients were more likely to be female (P = 0.044), and have bilateral disease (P = 0.020). Visual acuity score was higher in NMO patients (P = 0.034), and a greater proportion of NMO patients had a visual acuity score ≥5 (P = 0.003).

The frequency of patients without pattern-reversal and flash visual evoked potentials was higher in the NMO group (P = 0.015). The optic chiasm was affected in 25 percent of NMO patients and was unaffected in MS patients, although this difference did not reach statistical significance (P = 0.096). There were no differences with respect to the severity of swelling and enhancement of the optic nerve.