The need of blood flow to different organs varies rapidly over time which is why there is a need for sophisticated local regulation of blood flow. The term “dysregulation” just simply means that blood flow is not properly adapted to this need. Dysregulative mechanisms can therefore lead to an over- or under-perfusion. A constant over- or under-perfusion does not normally induce long-term damage. A repeated under-perfusion, such as a repeated mild reperfusion injury, however, leads to damage. Systemic dysregulation can be primary or secondary of nature. A secondary dysregulation (SVD) is due to other diseases such as autoimmune diseases. The term Flammer Syndrome (FS) named after the famous physician J. Flammer refers to a clinical entity comprising a complex of clinical features caused mainly by dysregulation of the blood supply which has previously been called primary vascular dysregulation.
People with FS tend to have cold extremities, prolonged sleep-onset time, altered drug sensitivity, low blood pressure and higher smell score, and increased retinal venous pressures as measured by means of ophthalmodynamometry. In the eye, the spatial irregularity of the retinal arteries is increased, and optic nerve head blood flow is correlated with finger blood flow indirectly indicating that the local regulation is disturbed.
Blood flow is, on average, reduced in glaucoma patients, particularly in patients with normal-tension glaucoma suffering from FS, and in patients with high-tension glaucoma, which progress despite a normalized intraocular pressure (IOP). A constant reduction of blood flow (as we see in SVD) can lead to atrophy but does not contribute to glaucomatous atrophy. An increased variation of microcirculation as commonly seen in glaucoma patients with FS, however, is clearly linked to occurrence and progression of glaucomatous optic neuropathy (GON). Oxygen supply to the eye fluctuates, either if IOP fluctuates on a high level or blood pressure on a low level or if autoregulation is disturbed. Autoregulation is disturbed in patients with primary vascular dysregulation (PVD). Unstable oxygen supply to the optic nerve head leads to oxidative stress, which in turn, leads to the production of peroxynitrite (ONOO-) which finally kills the cells. In this review, we are talking about pathogenesis of the FS and some suggested therapeutic options for it.
Correction to: Response to “Pay Attention to Blood Pressure and Oxygen Supply for Neurocritically Ill Patients: Each Pathology Deserves a Specific Treatment”
