A 32 year old woman complains of dull pain in her right eye for the past one week which worsens when moving her eye. Her past medical history includes multiple sclerosis which was diagnosed 6 months ago. An ophthalmoscopy shows pallor of the optic disc. Which anatomical site is most likely to be affected?
A. Optic nerve
B. Sclera
C. Optic radiation
D. Trigeminal nerve
E. Oculomotor nerve
Optic neuritis is a relatively common presenting symptom of Multiple Sclerosis. It is due to the demyelination of the optic nerve.
Optic neuritis (ON) Inflammation of the optic nerve
Presentation - Classically there is a triad of clinical features which are: o Reduced vision (of varying severity) → Usually unilateral. Progresses for less than 2 weeks and spontaneously improves within 3 weeks. o Eye pain → Particularly on movement o Impaired colour vision → Initially loss of red colour vision - One of the most common cause of optic neuritis is multiple sclerosis → Seen especially in caucasian populations The stem would usually (but not always) include a female patient as multiple sclerosis is more prevalent in the female gender - Examination o Swollen optic disc o Optic disc becomes pale later (4 to 6 weeks after onset)