1. What are some infectious causes of atypical optic neuritis?
1.1. Syphilis
1.2. Lyme
1.3. Bartonella
1.4. Tuberculosis
1.5. Others (Chikungunya virus,...)
2. What are some inflammatory causes of atypical optic neuritis?
2.1. Neuromyelitis optica (NMO)
2.1.1. What is NMO?
2.1.1.1. It is an idiopathic inflammatory demyelinating central nervous system disease. It causes unilateral or bilateral optic neuritis, classically transverse myelitis, and may follow a monphasic or polyphasic course.
2.1.2. What are the diagnostic criteria?
2.1.2.1. Optic neuritis and acute myelitis and 2/3 or the following: 1. Spinal cord lesion extending >3 vertebral segments; 2. Brain MRI findings not satisfying MS criteria; 3. NMO-IgG seropositivity
2.1.3. What are possible treatment options?
2.1.3.1. IV corticosteroids
2.1.3.2. Plasmapheresis
2.1.3.3. Chronic immunosuppression (azathioprine, mycophenolate mofetil, rituximab,...)
2.2. Sarcoidosis
2.3. Autoimmune optic neuropathy (AON)
2.3.1. What is AON?
2.3.1.1. It is a recurrent optic neuropathy requiring steroids with often positive ANA or anticardiolipin antibodies and no collagen vascular disease; Diagnosis is made with a biopsy of a non-sun exposed skin showing evidence of vasculitis
2.4. Chronic Relapsing Inflammatory Optic Neuropathy (CRION)
2.4.1. What is CRION?
2.4.1.1. It is a steroid responsive and steroid dependent inflammatory optic neuropathy but no evidence of sarcoidosis and no related neurological, systemic or ocular disease. It is a diagnosis of exclusion.
2.5. Others (systemic lupus erythemaotsis, Wegners,...)
3. What is the optic neuritis treatment trial (ONTT)?
3.1. It is a study that looked at patients 18-45 years of age with unilateral optic neuropathy and no systemic disease except if they had MS
3.2. What were the clinical outcomes of ONTT?
3.2.1. women: men ratio was 3:1
3.2.2. Pain/discomfort was present in the majority (92%)
3.2.3. Optic disc swelling was present in 35%; retrobulbar optic neuritis in 65%.
3.2.4. abnormal MRI with plaques was found in 49%
3.2.5. Any visual field defect is possible
3.3. What were the treatment arms in ONTT?
3.3.1. Grp 1: Oral prednisone; Grp2: Oral placebo; Grp 3: IV methyprednisolone
3.4. What were the results of the ONTT?
3.4.1. VA improved to 20/40 or better in all treatment arms so the treatment didn't affect final visual outcome
3.4.2. Grp that received IV methylprednisolone recovered faster at 1 month
3.4.3. Grp that received oral prednisone were more likely to have a recurrent episode of optic neuritis in one or the other eye
3.5. What was the rate of developing multiple sclerosis in the ONTT?
3.5.1. 50% regardless of MRI
3.5.2. 25% if MRI was normal at onset
3.5.3. 72% if 1 or more plaques seen at onset
4. What is optic neuritis?
4.1. It is a nonspecific term that describes optic nerve involvement by inflammation, infection or demyelination.
5. How does it present
5.1. Demyelination=typical optic neuritis
5.2. Atypical optic neuritis
5.3. What is considered atypical optic neuritis?
5.3.1. Atypical optic neuritis if disc swelling is severe, if there macular edema or exduate, if the vision doesn’t improve and if no pain. Usually seen in inflammatory and infectious.