Inclusion Criteria:

   1. Diagnosis of first episode of NA-AION in study eye with symptom onset within 14 days
   prior

   2. Subject age: Age >10

   3. NA-AION diagnosis requires:

      - disc edema seen and documented by site PI

      - visual field defect in the study eye consistent with NA-AION and mean deviation
      worse than 3.0 dB using the study visual field examination protocol

      - relative afferent pupillary defect (unless the fellow eye had previous NA-AION or
      other optic nerve or retinal disease that is not exclusionary)

Exclusion Criteria:

   1. Previous episode of NA-AION in the study eye only

   2. Intraocular pressure of >21 mm Hg in the study eye

   3. Clinical or pathological evidence of giant cell arteritis

   4. Diseases that may affect the optic nerve: glaucoma, multiple sclerosis, Alzheimer
   disease, and Parkinson disease. Evidence of optic disc drusen and optic nerve
   hypoplasia are not exclusion criteria given they are important parts of the study. We
   will not exclude significant retinal diseases, since they may be related to underlying
   etiologies giving rise to ODD, such as macular degeneration, retinal dystrophies, but
   eyes with significant retinal diseases will be analyzed separately.