Abstract

THE NEW PERCEPTION THAT AGE-RELATED MACULAR DEGENERATION MAY BE A VASCULAR DISEASE OPENS UP THERAPEUTICAL/PREVENTIVE THERAPEUTCICAL VISTAS FULL OF PROMISE: Part I

Dr. Tamás Fischer , M. D.

ABSTRACT

The endothelial system assures unhindered functioning and stability of the internal milieu maintaining vascular health and protecting against vascular injury, noxa. by excreting various substances: vasodilators and vasoconstrictors, growth factors and their inhibitors, proinflammatory and antiinflammatory agents, pro-thrombotic and fibrinolytic factors, and by keeping them in a strict equilibrium: endothelial dysfunction is the change of these properties, what is inappropriate with regard to the preservation of organ function. It is of great therapeutic significance that demonstrated the key role of disordered function of endothelium in the vessels supplying the affected ocular structures withblood:the recognition is of great preventive therapeutic significance that demonstrated the key role of ED in the vessels supplying the affected ocular structures with blood, i.e., that ED plays major role in the genesis and development of ED. Inflammation/parainflammation and immune-mediated processes (complement activation) play an important role in ED, in consecutive AMD pathogenesis. Chronic inflammation, a feature of AMD, is tightly linked to diseases associated with ED: AMD is accompanied by a general inflammatory response, in the form of complement system activation, similar to that observed in degenerative vascular diseases such as atherosclerosis. All these facts indicate that age-related macular degeneration (AMD) may be a vascular disease, part of systemic vasculopathy(!), in the end, as a matter of fact: this recognition/perception could have therapeutic implications.harm (noxa, i.e., risk factors [RFs]) → oxidative stress [OS] → endothelial activation [EA], endothlial dysfunction [ED], respectively → vacular injury, vascular disease). Wall of blood vessels including thoose in choroids also, may be triggered by several repeated and/or prolonged mechanical, physical, chemical, microbiological, immunologic, and genetic influences-impacts-stimuli (noxa, i.e., RFs), against which protracted response, the so-called host defense response may develop, and in consequence of this, vascular damage pathological consecutive changes ending in vascular injury (e.g., atherosclerose/age-related macular degeneration) ultimately, may develop.- AMD-risk factors also act directly on the endothelium through an increase in the production of reactive oxygen species, promoting an endothelial activation, which lead to endothelial dysfunction, the onset of vascular disease. Thus endothelial dysfunction is a connecting link between harm (noxa) and vascular injury: any kind of noxa start/trigger off an defensive chain that results in inflammation to specific tissues to eliminate/clear/avert (AMD-)risk factors, and even early AMD is associated with the occurrence of diffuse arterial vascular injury state at various stages[!]: patients with early AMD exhibit signs of systemic and retinal vascular alterations. All these facts indicate that age-related macular degeneration (AMD) may be a vascular disease, part of systemic vasculopathy(!), in the end, as a matter of fact: this recognition/perception could have therapeutic implications.

Keywords: age-related macular degeneration, endothelial dysfunction, oxidative stress, risk factors, primary and secondary prevention.