Glaucoma diagnosis
Contactless & stress-free glaucoma diagnosis
Background
The second most common cause of blindness in industrialized countries after diabetes is glaucoma. In Germany alone, around 28,000 people go blind every year as a result of glaucoma. Early diagnosis and treatment would prevent damage to the eye for the majority of these patients.
Tonometry, the determination of intraocular pressure, is an important tool in the diagnosis and treatment of glaucoma. However, intraocular pressure is not sufficient as the sole criterion for assessing a disease. In around 30% of patients, damage to the retina can be detected even if the intraocular pressure is within the normal range (low-pressure glaucoma). In contrast, some patients do not suffer any damage even if their intraocular pressure has been elevated for years. A combination of parameters is therefore required to successfully diagnose glaucoma.
Causes
It is assumed that blindness caused by glaucoma is due to a circulatory disorder of the photoreceptors and the optic nerve. Blood flow in the eye, particularly in the retina, is therefore regarded as a very meaningful parameter in the early detection of glaucoma.
Measurement technology
A stationary measuring system consists of a mechanical adjustment unit, an optical measuring head and control and evaluation electronics. It can be used to measure pulsatile eye movements with high resolution.
The optical measuring system is based on a special interferometer, which enables dynamic measurement of the variation of the distance between the measuring setup and the cornea with a resolution of approx. 10 nm. The realized measuring system is absolutely load-free and, in contrast to other commercially available systems, allows an irradiation duration or measuring time of up to eight hours a day (according to laser protection guidelines).
Miniaturization
In addition to the high-precision interferometric measuring system already implemented as a table-top device, a camera-based measuring system is being realized. This facilitates the miniaturization of the concept into a mobile handheld device. This makes it possible to continuously determine intraocular pressure and the blood supply to the eye postoperatively or for diagnostic purposes.
The realization of such a compact system opens up new possibilities for diagnostics and therapy not only for glaucoma patients, but also for diseases related to the blood supply to the brain, for example.
Projects
Personal Health Monitor (PHMon)