Glaucoma occurs in all regions of the world. Certain types of glaucoma, however, occur more frequently in some areas. Japanese and Koreans, for example, tend to suffer more often from normal-tension glaucoma (NTG), whereas North Americans are more likely to suffer from high-tension glaucoma (HTG).
Mechanisms leading to intraocular pressure (IOP) increase:
The cause of IOP increase is well known for some types of glaucoma (e.g., angle-closure glaucoma) but lesser known in primary open-angle glaucoma (POAG). In addition to a certain genetic predisposition, all known risk factors for arteriosclerosis are also risk factors for IOP increase.
The role of a genetic predisposition varies in different types of glaucoma. The inheriting mode is often complex and most often not yet totally clear.
Development of glaucomatous damage:
Mechanical stains as well as ocular perfusions play a central role in the development of glaucomatous damage.
Diagnosis of glaucomatous damage:
A lot of new instruments have emerged to diagnose and quantify glaucomatous damage. The search for an optimal biomarker is still ongoing. At present, the visual field is still most important.
Glaucoma leads to visual field defects, disturbances of color vision, contrast sensitivity, and dark adaptation. For more details on quantification of visual field (perimetry), see Glaucoma Research in Basel.
Treatment of glaucoma:
IOP can be decreased by laser, operations, and, in particular, medications. In addition to reducing IOP, alternative possibilities for treating glaucoma, particularly normal-tension glaucoma, exist (see Glaucoma Research in Basel).
Research at our Department of Ophthalmology
In cooperation with Professor Fankhauser and Professor Bebie from the University of Bern, the group in Basel has developed visual field indices, the Octopus program G1 / G2, and the Bebie curve.
The Basel research team focuses mainly on the role of ocular blood flow in glaucoma. This takes place at various stages.
Ocular blood flow is measured using various methods in the eye (and other organs) of glaucoma patients and results are compared to healthy controls. Our studies show that ocular blood flow is often reduced at baseline levels, not only in the eye but also in other organs. More important, however, is the observation that capacity to regulate blood flow is reduced. In other words, the regulation is not capable to keep ocular blood flow independent of IOP or blood pressure fluctuation. The blood vessels also do not react as anticipated when stimulated, e.g., by flickering light, cold, emotional stress, etc. This deficient regulation of blood vessels is known as vascular dysregulation.
In vitro studies:
We have shown in isolated blood vessels that endothelial cells take part in the regulation of blood flow and that these endothelial cells are affected in glaucoma, particularly in normal-tension glaucoma. The effects of different medications and their mechanisms of action were tested.
Methods to measure ocular blood flow:
The research group of Josef Flammer has various instruments to measure ocular blood flow and blood flow in other parts of the body. The group is also involved in the development of new measuring methods.
Diagnosis of glaucoma:
Glaucoma can be diagnosed phenomenologically; in other words, we can see and quantify the damage in the visual field and in the optic nerve head. Even more important is the identification of risk factors, such as increased IOP, low blood pressure, or vascular dysregulation. Our group in Basel focuses on vascular dysregulation.
Our research group has also focused on the development of biomarkers. Changes, for example, in the lymphocytes of the circulating blood are not only indicative of glaucoma but can also provide us information of the mechanisms involved in the glaucomatous damage.
Our group does fistulating operations and has also introduced new operating techniques, such as the stitchless trabeculectomy with a long tunnel.
Our research has been documented in the form of books and articles published in different scientific journals (see Literature).