Classic presentation of optic neuropathy
☝ young female
☝painful ( with eye movements) decreased visual acuity
☝ central or centrocecal visual field defect
☝ abnormal color vision (dyschromatopsia)
☝ a relative afferent pupillary defect.
☝optic disc changes may or may not be present ( depending on the portion of the nerve affected)
☝ with or without normal fundus.
causes of Optic neuritis
☝ idiopathic
☝ demyelinating disease ( MS)
☝ autoimmune disease( SLE)
☝ inflammatory disease ( sarcoidosis)
☝ infections ( Lyme and syphilis)
☝ vaccinations.
Value of MRI of the orbits and brain
☝ confirm the presence of optic nerve inflammation( increased enhancement)
☝ assess for white matter lesions ( preiventricular white matter ( corpus callosum)
☝ exclude other causes of optic neuropathy.
☝ best MRI to be ordered
• T2 weighted with fat suppression
• FLAIR ( fluid attenuation inversion recovery)
The 10-year risk of developing MS
☝> 50% in optic neuritis patients with positive MRI results ( one or more white matter lesion)
☝< 20% in those with Free MRI ( no white matter lesions) .
Best Treatment of optic neuritis according to ONTT
☝ intravenous methylprednisone
(1 g daily) for 3 days
☝ oral prednisone (1 mg/kg per day) for the following 11 days ( without gradual withdrawal)
Results of treatment
☝ faster recovery of vision with the same final VA results with placebo
☝ decreased risk of developing MS in the 2 years following treatment.
☝ oral steroids alone are not indicated as it increases the rate of recurrent attacks of ON and does not decrease the risk of developing MS in 2 yrs following treatment.
