Methanol is a toxic alcohol that can cause optic neuropathy leading to bilateral optic disc edema, which may resemble papilledema but is due to direct toxic injury, not increased intracranial pressure.

🧪 Pathophysiology of Methanol Toxicity
Methanol is metabolized in the liver by alcohol dehydrogenase to:

Formaldehyde, then to

Formic acid (the main toxic metabolite)

Formic acid inhibits mitochondrial cytochrome oxidase → leads to:

Lactic acidosis

Retinal and optic nerve toxicity

CNS depression

👁️ Ocular Findings
Bilateral optic disc swelling

Decreased visual acuity (may progress to complete blindness)

Central scotomas on visual field testing

Pupils may be sluggish or non-reactive to light

Fundus: hyperemic or pale swollen discs, sometimes hemorrhages

⚠️ Key Distinguishing Features
Feature	Methanol Toxicity	True Papilledema
Cause	Toxic optic neuropathy	Raised ICP
Vision loss	Early and profound	Mild early, progressive
Systemic symptoms	Metabolic acidosis, CNS depression	Headache, nausea, diplopia
Imaging	Normal brain/optic nerve (early)	May show mass, hydrocephalus, etc.
CSF pressure	Normal	Elevated
Fundus	May mimic papilledema	True disc swelling, often with hemorrhages
🧑‍⚕️ Management
Fomepizole or ethanol (inhibit alcohol dehydrogenase)

Hemodialysis (removes methanol and formic acid)

Bicarbonate (for acidosis)

Folate (enhances formate metabolism)

Supportive care and ophthalmology consultation