Neuro

Retrobulbar Optic Neuropathy

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Retrobulbar Optic Neuropathy, Optic Neuritis, Papillitis

  • Epidemiology
  1. Young patients predominate (esp. age 20 to 45 years old)
  • Pathophysiology
  1. Immune-mediated inflammatory demyelination of the Optic Nerve
  2. Demyelination results in Retinal Ganglion cell axon degeneration
  • Causes
  1. Multiple Sclerosis
  2. Encephalomyelitis
  3. Posterior Uveitis
  4. Optic Nerve vascular lesions
    1. Central Retinal Artery Occlusion
    2. Central Retinal Vein Occlusion
    3. Anterior Ischemic Optic Neuropathy
  5. Tumor
    1. Optic Nerve glioma
    2. Neurofibromatosis
    3. Meningioma
  6. Fungal infections
  7. Medications
    1. Aminosalicylic acid
    2. Chloramphenicol
    3. Ethambutol
    4. Isoniazid
    5. Penicillamine
    6. Phenothiazines
    7. Phenylbutazone
    8. Quinine
    9. Streptomycin
  • Risk Factors
  1. Multiple Sclerosis
  2. White Race
  3. Female Gender
  4. Age 20 to 45 years old
  • Associated Conditions
  1. Multiple Sclerosis
    1. Optic Neuritis is the presenting finding in 15-20% of Multiple Sclerosis (overal seen in 50% of MS cases)
  • Symptoms
  1. Pain behind affected eye is variably present
    1. Worse with eye movement
  2. Central Vision Loss
  3. Loss of color vision
  4. Impaired vision develops over hours to days
    1. Affects one or both eyes
    2. Rarely results in total blindness
    3. Acuity often worse than 20/100
  • Signs
  1. Unilateral optic disc swelling and blurring of the disc margin
    1. Optic Nerve pallor, hyperemia or Papillitis present (Papilledema)
    2. Optic disc may appear normal in Retrobulbar Optic Neuropathy
  2. Pupil light reflex abnormal
    1. Afferent Pupillary Defect
  3. Provocative maneuvers
    1. Extraocular Movement painful
    2. Pressure on globe painful
  4. Decreased Visual Acuity amd Visual Field deficits
  • Labs
  • Cerebrospinal Fluid
  1. WBC: Normal or 10-20 WBC present
  2. Oligoclonal bands may be present
  • Imaging
  1. Brain MRI and Orbit MRI with gadolinium contrast
    1. Confirm acute demyelinating Optic Neuritis
    2. Identify concurrent CNS findings suggestive of Multiple Sclerosis (e.g. periventricular white matter deficits)
  • Management
  1. Hospital admit
  2. IV Glucocorticoids
    1. Methylprednisolone 250 mg IV every 6 hours for 3 days
    2. Reduces chance of future MS
  • Course
  1. 30-50% develop Multiple Sclerosis within 15 years
  • References
  1. Yanoff (1999) Ophthalmology, Mosby, p. 6.2-6.4