Toxic-nutritional optic neuropathy

Not only the level, but in the grey zone the methylmalonic acid too. And know beforehand whether a supplement has already been taken — after that the value cannot be judged.

Folic acid alone can improve the anaemia and thereby mask the shortage, while the nerve goes on taking damage. B12 belongs first, or at least at the same time.

Both act on the same nerve, and dropping them one at a time achieves less here than both at once. For the alcohol, support is worthwhile, precisely because it seldom stands alone.

Bring all the packets, including those from the chemist. Only someone who knows the list can find the one drug that matters here — and plan the eye checks.

Both are more sensitive than acuity and show the course long before letters vanish from the chart. For comparison, a first measurement as early as possible counts.

A paled optic disc means fibres have been lost. What remains possible is protecting the rest — which is why every week counts here.

No treatment repairs a damaged optic nerve. What works is removing the trigger — alcohol, tobacco, ethambutol, amiodarone, methanol — and refilling B12, B1 and folate. The earlier that happens, the more returns; after months the loss stays. In methanol poisoning, fomepizole or ethanol act as an antidote by occupying the same enzyme and preventing breakdown into the damaging substance — there hours count.

The loss of vision develops slowly over weeks to months, on both sides and fairly evenly — that course separates it from a vessel blockage, which comes suddenly. Colour vision for red and green is lost early, often before sharpness falls. After removing the trigger it improves over three to twelve months, if that happens early enough. Ethambutol acts dose-dependently, usually after two to eight months of treatment.

Colour vision often suffers before sharpness. A good self-test: look at a red object with one eye and then the other and compare how deep the red appears.

Reading becomes hard and faces blur, while one still finds one’s way around a room. That separates this damage from a detached retina, which takes the edge first.

A sudden loss in one eye is something else and more urgent. Here it takes weeks and affects both sides similarly — and that is exactly what points to poison and shortage.

These three rarely come alone. Someone who drinks heavily usually eats poorly, and smoking further worsens the nerve’s supply. The combination is the commonest cause of all.

Some drugs can damage the optic nerve, and for a few an eye check during treatment is foreseen. Anyone who sees worse on a new medicine reports it at once and stops nothing on their own.

The most important value. It can lie in the lower normal range and still be too little — so in the grey zone a second value belongs alongside.

Shows whether B12 is really lacking inside the cells and settles exactly those cases where the B12 value alone does not help.

Belongs measured too, because both shortages often occur together. Folic acid alone improves the blood count and lets the nerve damage carry on — so always look at both.

Rises with B12 and folate shortage and makes an existing lack visible when the other values sit on the border.

The key missing nutrient.

Works together with B12.

If deficient, medically guided.

As a combo.

In pregnancy clearly established against neural-tube defects, otherwise mainly with deficiency. Can mask a B12 deficiency — watch both.

A medicine against an overactive thyroid is not among the triggers — but amiodarone is, a heart medicine that also throws the thyroid off. Anyone taking it has eyes and thyroid checked regularly.

Alcohol and tobacco together with a shortage of B vitamins are the classic combination. With heavy drinking the sugar metabolism comes on top — together the two make the nerve doubly vulnerable.

Cause and diet go together.

Here the nutrient deficiency is the cause, not a side note. B12, folate and B1 are replaced in a targeted way — the earlier, the more sight is kept. Alcohol and smoking are the most common triggers.