Researchers develop ‘chewing gum’ test to prevent blindness

GCA is caused by inflammation of the lining of arteries in the head, most commonly in the tples, which restricts arterial blood flow. Symptoms can include vision probls, headaches, scalp tenderness and jaw pain.The disease, which is most commonly observed among people aged 50 and older, can be hard to diagnose because early symptoms are often subtle and found in a range of other diseases.For example, claudication of the jaw muscles (cramping pain caused by inadequate arterial blood flow) is a specific indicator of GCA, but there is no current clinical test to differentiate it from other causes of jaw pain. GCA patients with jaw claudication have a higher risk of permanent visual loss, but this symptom isn’t commonly reported because many people favour soft food as they age.The Save Sight Institute said on 31 May that its researchers had developed a straightforward ‘chewing gum’ test designed to unmask this jaw symptom. By chewing gum at a rate of one chew per second the test can reproduce a patient’s telltale pain, prompting further investigation with a blood test and an arterial biopsy to confirm diagnosis.In a letter published in the New England Journal of Medicine, researchers presented two cases where the chewing gum test allowed clinicians to better characterise jaw pain, confirm a diagnosis and successfully treat both patients. GCA is one of the most common causes of blindness in older people, Professor Peter McCluskey, director of the Save Sight Institute and professor of clinical ophthalmology at the University of Sydney, said. Not only can it send you blind, but it can kill you. It also can affect vision extrely quickly. If one eye is already involved, around one third of people go blind in the other eye within a day, another third within a week and the raining third within a month. It’s a very serious condition which requires rapid and correct diagnosis. At the time of publication, it was said the Sydney research team was undertaking further studies to validate the chewing gum test.