Optic Neuritis Flashcards
What is optic neuritis?
Inflammation of the optic nerve, causing visual loss and pain, often associated with demyelinating diseases.
What are the common symptoms of optic neuritis?
Sudden, usually unilateral vision loss, eye pain (especially with movement), and colour desaturation.
What is the typical age range for optic neuritis onset?
It commonly affects individuals aged 20-50 years.
What is the most common cause of optic neuritis?
Multiple sclerosis (MS), a demyelinating disease.
What are other potential causes of optic neuritis?
Neuromyelitis optica, infections (e.g., syphilis, Lyme disease), autoimmune diseases, and sarcoidosis.
What is the pathophysiology of optic neuritis?
Demyelination or inflammation of the optic nerve disrupts signal transmission between the retina and brain.
What are the signs of optic neuritis on clinical examination?
Reduced visual acuity, afferent pupillary defect (RAPD), and optic disc swelling (papillitis) or normal disc appearance (retrobulbar).
What is retrobulbar optic neuritis?
Inflammation of the optic nerve behind the globe, causing vision loss without visible optic disc swelling.
What is the role of an afferent pupillary defect (APD) in diagnosing optic neuritis?
An APD indicates optic nerve dysfunction and is a key clinical sign in optic neuritis.
What is Uhthoff’s phenomenon?
Worsening of optic neuritis symptoms with heat or exercise.
What is the relationship between optic neuritis and multiple sclerosis (MS)?
Optic neuritis is often the first presenting feature of MS and occurs in up to 50% of patients with MS.
What is the role of MRI in optic neuritis?
MRI identifies optic nerve inflammation and detects lesions suggestive of MS in the brain or spinal cord.
What is the role of visual evoked potentials (VEP) in optic neuritis?
VEP measures the speed of signal conduction in the visual pathway, showing delayed responses in demyelination.
How is optic neuritis typically treated?
High-dose intravenous corticosteroids (e.g., methylprednisolone) to hasten recovery, followed by oral steroids.
What is the natural prognosis of optic neuritis without treatment?
Most patients recover vision within weeks to months, but some may have residual visual deficits.
What are the differential diagnoses for optic neuritis?
Ischaemic optic neuropathy, compressive optic neuropathy, Leber hereditary optic neuropathy, and retinal detachment.
What is neuromyelitis optica (NMO)?
An autoimmune condition causing severe optic neuritis and transverse myelitis, often associated with aquaporin-4 antibodies.
What investigations are performed to exclude other causes of optic neuritis?
Blood tests (e.g., infectious or autoimmune markers), lumbar puncture, and imaging studies.
What is the prognosis for vision recovery in optic neuritis?
Vision recovery is generally good, but some patients may experience recurrent episodes or MS-related progression.
What is papillitis?
Optic neuritis with visible swelling of the optic disc.
What systemic symptoms may be associated with optic neuritis?
Fatigue, weakness, or neurological symptoms suggestive of underlying conditions like MS or NMO.
What is the role of lumbar puncture in optic neuritis?
To assess cerebrospinal fluid (CSF) for markers of inflammation or infection and aid in diagnosing MS or NMO.
What is Leber hereditary optic neuropathy (LHON)?
A mitochondrial genetic disorder causing bilateral optic neuropathy, often confused with optic neuritis.
What lifestyle advice is given to patients with optic neuritis?
Avoid overheating, manage stress, and attend regular follow-ups for underlying conditions like MS.
What is the significance of early diagnosis in optic neuritis?
Early treatment can hasten recovery, identify associated systemic conditions, and prevent further episodes.
