Which of the following is a documented cause of optic neuritis?

• A. Infectious diseases (bacterial, viral, fungal)
• B. Glaucoma
• C. Cataract
• D. Diabetic retinopathy

Answer: (A)

Optic neuritis is inflammation of the optic nerve, and infections are a well-documented cause because pathogens can directly involve the nerve or trigger inflammatory demyelination leading to neuritis. Bacterial, viral, and fungal infections have all been reported to contribute to this condition.

The other conditions affect different parts of the eye or different disease processes: glaucoma causes optic neuropathy mainly from chronic elevated pressure, not acute inflammatory neuritis; cataract is a lens opacity and does not involve the optic nerve; diabetic retinopathy involves retinal vessels and retina, not the optic nerve inflammation.