Which finding is most characteristic of methanol poisoning rather than ethylene glycol poisoning?

Which finding is most characteristic of methanol poisoning rather than ethylene glycol poisoning?

• A. Visual disturbances
• B. Calcium oxalate crystals
• C. AKI
• D. Metabolic alkalosis

Answer: (A)

Ocular involvement is the distinguishing feature. Methanol is metabolized to formic acid, which specifically damages the optic nerve and retina, leading to visual disturbances that can progress to blurry vision or irreversible blindness. Ethylene glycol, on the other hand, tends to cause metabolic acidosis and kidney injury, with calcium oxalate crystals often seen and contributing to tubular damage. Because visual disturbances directly reflect optic nerve toxicity from formic acid, they are most characteristic of methanol poisoning. Calcium oxalate crystals point more to ethylene glycol; AKI and metabolic acidosis can occur with both toxins, and metabolic alkalosis is not typical.

Ocular involvement is the distinguishing feature. Methanol is metabolized to formic acid, which specifically damages the optic nerve and retina, leading to visual disturbances that can progress to blurry vision or irreversible blindness. Ethylene glycol, on the other hand, tends to cause metabolic acidosis and kidney injury, with calcium oxalate crystals often seen and contributing to tubular damage. Because visual disturbances directly reflect optic nerve toxicity from formic acid, they are most characteristic of methanol poisoning. Calcium oxalate crystals point more to ethylene glycol; AKI and metabolic acidosis can occur with both toxins, and metabolic alkalosis is not typical.