Which investigations should be performed to confirm a diagnosis of opt

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Investigations to confirm optic neuritis and exclude other conditions include:

Clinical assessment: Detailed history and neurological examination to identify typical features such as painful vision loss and to exclude other neurological causes .
Magnetic Resonance Imaging (MRI) of the brain and orbits: MRI is essential to confirm optic nerve inflammation and to exclude other causes such as compressive lesions or demyelinating plaques suggestive of multiple sclerosis .
Visual function tests: Visual acuity, colour vision, and visual field testing help document the extent of visual impairment.
Ophthalmological examination: Slit-lamp examination with dilated pupils to exclude uveitis or other ocular inflammatory conditions .
Blood tests: To exclude infectious or inflammatory causes if clinically indicated, although not routinely required for typical optic neuritis .
Referral to ophthalmology and neurology specialists: For further assessment and confirmation of diagnosis, including consideration of lumbar puncture or other investigations if atypical features are present .

These investigations help confirm optic neuritis and exclude other causes such as uveitis, glaucoma, or compressive optic neuropathies.

Which investigations should be performed to confirm a diagnosis of optic neuritis and rule out other conditions?