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

青光眼是一组眼部疾病，共有一种独特的视神经损伤，可导致失明。青光眼的发病率随着年龄的增长而显著增加。这种疾病的一个主要困难是，大多数青光眼患者直到开始失去视野的实质部分才注意到任何症状。这种视力丧失是永久性的。世界卫生组织估计，全世界有1350万青光眼患者。目前，约有30万加拿大人被诊断患有青光眼。据估计，另外150，000加拿大人患有青光眼，但仍未确诊。我们最近的研究表明，筛板的生物力学顺应性之间的迅速恶化的青光眼患者和稳定型青光眼患者显着不同。筛板是特化巩膜的多孔盘，组成视神经的轴突通过筛板离开眼睛，并且供给眼睛的许多毛细血管和血管通过筛板进入。我们的静态测量结果显示，高风险患者的筛板位移是低风险患者的10倍以上。这一发现表明，高风险患者的椎板刚性较低，因此具有较大的脉动，导致轴突损伤较大，青光眼进展迅速。本课题的目的是研制一种能测量筛板脉动的装置，用于高危青光眼的早期诊断。该装置应具有微米级的空间分辨率和毫秒级的时间分辨率。该设备的一个主要优点是，它将能够在合理的短时间内进行测量，并且具有高度的可访问性（不需要服药或进行眼科手术来降低长期眼内压）。因此，青光眼高危人群可以在视力丧失开始之前被识别出来，有利于加拿大人的健康，并防止与青光眼相关的低生活质量和高成本

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