New non-invasive device for measuring the biomechanics of the optic nerve head

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Glaucoma is a group of eye diseases that share a distinct type of optic nerve damage that can lead to blindness. The prevalence of glaucoma increases markedly with age. A major difficulty of this disease is that most people who have glaucoma do not notice any symptoms until they begin to lose substantial segments of their visual field. This visual loss is permanent. The World Health Organization estimates that there are 13.5 million people with glaucoma worldwide. Currently, about 300,000 Canadians are diagnosed with glaucoma. It is estimated that another 150,000 Canadians have glaucoma but remain undiagnosed.Our recent studies suggest that the biomechanical compliance of the lamina cribrosa differs dramatically between patients with rapidly deteriorating glaucoma and patients with stable glaucoma. The lamina cribrosa is the porous disc of specialized sclera through which the axons composing the optic nerve leave the eye and many of the capillaries and blood vessels feeding the eye enter. Our static measurements show that the displacement of the lamina cribrosa of high-risk patients is more than 10 times larger than those of low-risk patients. This finding suggests that the lamina of high-risk patients is less rigid and thus has a larger pulsation, resulting in larger damage to the axons and the rapid progression of glaucoma. However, there is presently no equipment that can measure this pulsatility.TTie objective of this project is to develop a device that can measure the pulsatility of the lamina cribrosa, for early diagnosis of high-risk glaucoma. The device should have micron spatial resolution and millisecond temporal resolution. A major advantage of this device is that it will be able to perform measurements within a reasonably short time, and with high accessibility (no need to take medicine or have ocular surgery to reduce long-term intraocular pressure). As a result, individuals that have high-risk for glaucoma can be identified before loss of vision starts, benefiting the health of Canadians, and preventing the low quality-of-life and high costs related to glaucoma