Glaucoma is a condition that causes damage to the eye’s optic nerve, which progressively worsens if not managed in time. It’s often associated with a buildup of fluid inside the eye, leading to pressure. The increased pressure can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high eye pressure continues, glaucoma can cause permanent loss of vision. According to the American Academy of Opthalmology, glaucoma is the world’s leading cause of irreversible blindness, affecting 3.54 per cent of the global population aged between 40 and 80. The organisation estimates that the number of people with glaucoma worldwide will increase to 111.8 million by 2040, disproportionally affecting those in Asia and Africa. There is no cure; treatment is focused on preventing further damage.
The pancake link
The researchers at UCL say the appearance of pancakes depends on how water escapes the batter mix during the cooking process — and this varies with the thickness of the batter. They add that studying how water escapes from the pancakes can help understand how flexible sheets, such as the human retina, interact with fluids and vapours, such as those that occur in glaucoma. “Pancakes come in many shapes and sizes… We’ve discovered that the variations in texture and patterns result from differences in how water escapes the batter during cooking and that this is largely dependent on the thickness and spread of the batter,” said co-author Professor Ian Eames.
The study, published in Mathematics TODAY, compared recipes for 14 different types of pancakes from across the world. While the Indian dosa didn’t make the cut, the Canadian ploye, Malaysian lempeng kelapa and the French crepe were among those that were part of the research. The scientists used two metrics to characterise the pancake geometry and the properties of their batter mixture. The team analysed and plotted the aspect ratio — the pancake diameter to the power of three in relation to its volume of batter — and the baker’s percentage which is the ratio of liquid to flour in the batter or the thickness of the batter.
To explore how these ratios influence the textures and patterns of pancakes, the scientists made batters with a fixed amount of flour and egg but different amounts of milk. Pancakes were made in the same pan, at the same heat and without fat.
Scientists found that thick batters formed pancakes with irregular craters on the bottom. Water vapours released during cooking get trapped, unevenly lifting the pancake from the pan. Islands form on top surface as the pancake isn’t of uniform thickness.
Thinner batters form pancakes with an even colour on the bottom surface as water vapour is released smoothly from the base as it cooks. This effect is also seen in small pancakes irrespective of the thickness of the batter. The thinnest batters form pancakes with an even coloured bottom surface which is dotted with dark spots. Water vapours escape smoothly across the bottom surface and through channels in the batter.
The team found that if the pancake batter spread more smoothly and easily in the pan, it would result in a more even pancake, to a point. The really thin batter needs to be spread physically, like making crepes.
Relation to eye surgery
The researchers say that understanding the interaction between the water vapour and the batter to create the different textures on the pancake help in improving glaucoma surgeries. How? Co-author Dr Yann Bouremel, UCL Institute of Ophthalmology, explains: “Glaucoma surgery is about creating a path for the liquid called aqeous humour through the eyes to reduce the pressure and preserving the sight of patients. We are improving this technique by working with engineers and mathematicians.”
“It’s a wonderful example of how the science of everyday activities can help us with the medical treatments of the future,” adds co-author Professor Sir Peng Khaw.