A 70-year-old woman with a sudden onset of double vision also complains of headache and pain chewing her food. What is going on?

It is important to get this one right. A mistake here will have serious consequences for the patient and the eye specialist.

The symptom of sudden onset puts me on high alert but puts me on even higher alert are the symptom of headache and pain on chewing. In my mind, this means giant cell arteritis (inflammation of the arteries) unless proved otherwise. Inflammation can lead to a total blockage of these arteries.

Giant cell arteritis, also called temporal arteritis because it affects the temporal arteries (at the side of the head) become inflamed. A serious condition that requires urgent treatment as it can lead to bilateral blindness in a few hours. It is an inflammation of the lining of the arteries which affects mainly people over the age of 50.

The main symptoms are:

• Frequent, severe headaches
• Pain and tenderness over the temples
• Jaw pain while eating or talking
• Double vision
• Loss of vision in one or both eyes.

More general symptoms are flu-like symptoms, unintentional weight loss, depression and tiredness.

Patients who become blind because of giant cell arteritis usually (80–90% of the time) experience arteritic ischaemic optic neuropathy. This means that there is no blood or a reduced supply of blood to the optic nerve, which becomes starved of oxygen and ceases to function in a short period.

Any patient you suspect of having giant cell arteritis deserves emergency treatment by an ophthalmologist.