Toxic and Nutritional Optic Neuropathy

Key points

• • Some poisons and nutritional lacks damage the optic nerve, giving a slow, painless loss of central vision in both eyes together.
• • Methanol (wood alcohol) poisoning can cause sudden, severe visual loss and blindness by damaging the optic nerve.
• • Long-term tobacco and alcohol use, with a poor diet, causes a gradual dimming once called tobacco-alcohol amblyopia and now regarded as a toxic and nutritional optic neuropathy.
• • A lack of vitamin B12 or other B vitamins can also harm the nerve, and correcting it early may help.
• • The typical field loss is a blur in the centre of vision (a central scotoma), and colour vision is affected first.