Glaucoma is the most prevalent optic neuropathy of adults
About
- Atrophy of the optic nerve
- End result of multiple pathologies damaging the nerve
Clinical
- Loss of vision usually acuity
- Colours appearing subtly washed out in the affected eye.
- Optic disc may look pale
- Headache/weight loss/PMR : could it be GCA
- Look for papilloedema
- Marcus Gunn pupil
Onset
- Acute over minutes and hours: consider Ischaemia, Inflammatory, Traumatic
- Sub-acute over a few days
- Chronic over weeks and months: Compressive, Heredofamilial and Degenerative, Indolent inflammation, Toxic/nutritional, Infiltration of the nerve
Causes of Optic atrophy
- Idiopathic Intracranial hypertension
- Glaucoma
- Multiple sclerosis and retrobulbar neuritis
- Traumatic neuropathy of optic nerve
- Ischaemic optic neuropathy
- Chronic papilloedema
- Chronic optic neuritis
- Hereditary optic neuropathies (e.g. Leber's optic neuropathy)
- Toxic retinopathies (e.g. isoniazid, toluene from glue sniffing)
- Tobacco retinopathy and Alcohol
- B12/folate deficiency
- Retinal degeneration e.g. retinitis pigmentosa
- Retinal storage diseases (e.g. Tay-Sachs)
- Radiation neuropathy
- Syphilis
Investigations
ESR and CRP for temporal arteritis and Temporal artery biopsy if clinical suspicion for temporal arteritis
Opening pressure on LP for raised ICP (after neuroimaging
to rule out mass)
CSF analysis to look for more widespread CNS process
CSF immunoglobulins to look for markers of multiple sclerosis
FTA-ABS and RPR to screen for syphilis
B12 and Folate levels to screen for hematologic etiology
Toxicology screen to look for endogenous poisons
Thyroid function tests to screen for dysthyroid contribution to optic
neuropathy
CT/MRI orbits and brain