J Flammer, M Mozaffarieh:
Autoregulation, a balancing act between supply and demand
|In an earlier chapter of this webpage, we have shown that fluctuations of intraocular pressure and fluctuations of blood pressure are significant risk factors for the occurrence and progression of glaucoma damage. Large fluctuations in perfusion pressure can exceed the regulatory capacity, leading to unstable ocular blood flow, especially to the optic discs. This ocular perfusion is, of course, even more unstable when autoregulation is impaired. Causes and consequences of defective autoregulation are described in this review.
D Gherghel, S Orgül, K Gugleta, M Gekkieva, J Flammer:
Relationship Between Ocular Perfusion Pressure and Retrobulbar Blood Flow in Patients With Glaucoma With Progressive Damage
|Flammer's research group was the first to observe that glaucoma patients with progressive visual field damage despite normal or well-adjusted intraocular pressure often have vasospasm in the fingers. Gherghel et al. then showed that glaucoma patients with progressive visual field damage despite good eye pressure have altered, respectively decreased, regulation of ocular blood flow. This means that such people have a disturbed autoregulation of the ocular blood flow and thus an unstable oxygen supply.
MC Grieshaber, M Mozaffarieh, J Flammer:
What Is the Link Between Vascular Dysregulation and Glaucoma?
|Flammer and coworkers classified vascular dysregulation into primary and secondary vascular dysregulation (PVD and SVD) and observed that PVD contributes to glaucomatous optic disc atrophy, whereas SVD contributes to bland optic disc atrophy.
In this review, Grieshaber et al. describe these relationships.
J Barthelmes, MP Nägele, V Ludovici, F Ruschitzka, I Sudano, AJ Flammer:
Endothelial dysfunction in cardiovascular disease and Flammer syndrome—similarities and differences
|The main cause of vascular dysregulation is vascular endothelial dysfunction. This is especially true for the retina and optic nerve head because these blood vessels are not innervated and thus not under the direct influence of the autonomic nervous system. There are two major forms of vascular endotheliopathy. The first form is acquired and is seen in patients with risk factors for atherosclerosis, particularly those with a metabolic syndrome. The second form is at least partially inborn and is observed particularly in people with Flammer syndrome. The review by Barthelmes et al. shows the similarities and the differences.