Retinal Circulation in Arterial Disease

Abstract

Hypertension has profound effect on the structure and function of the eye. In this chapter, we will focus on hypertensive retinopathy. Only for the sake of completeness, it should be mentioned that hypertension-related changes also include hypertensive optic neuropathy and hypertensive choroidopathy. Moreover, there are ocular diseases where hypertension is a potential risk factor, e.g., age-related macular degeneration and glaucoma. Most importantly, hypertension causes structural and functional vascular changes. We elaborate on the current knowledge of these processes, including innovative fi ndings related to new applied technologies. Vascular RemodelingSince the pathophysiological concept of vascular remodeling was in detail described in Chap. 5 , only few words will be mentioned. Remodeling can be of two typeseutrophic and hypertrophic, but both types result in an increase in the media-tolumen ratio of small arterioles. In eutrophic remodeling, both the outer and the lumen diameter are reduced, but the media cross-sectional area is not increased because the increase in the wall thickness-to-lumen diameter ratio is caused by a rearrangement of the smooth muscle cells around a narrowed lumen [ 1 ]. In contrast, in hypertrophic remodeling, an enhanced growth response resulting in an increased media cross-sectional area was documented. Eutrophic remodeling predominates in patients with essential hypertension, and hypertrophic remodeling was found in patients with severe and long-standing hypertension.