The role of endothelin in the pathophysiology of glaucoma

Abstract

Overall, we believe that the body of evidence supports the following conclusions; i) endothelin is a potent vasoconstrictor that plays a role in ocular physiology, ii) endothelin may play a role in the pathophysiology of glaucoma and iii) modulation of the endothelin system with newly discovered potent antagonists holds promise in treating glaucoma through both pressure-dependent and pressure-independent pathways.

Association Between Plasma Endothelin-1 and Severity of Different Types of Glaucoma

“…13 Increased IOP is the most important risk factor for glaucoma, but the pathogenesis of glaucoma is multifactorial and unclear. 2,13 The role increased IOP plays in glaucomatous change remains to be elucidated. 2 Studies have shown that some patients might not develop glaucomatous changes despite increased IOP, whereas other patients show evidence of glaucomatous changes in the absence of increased IOP.…”

“…2,13 The role increased IOP plays in glaucomatous change remains to be elucidated. 2 Studies have shown that some patients might not develop glaucomatous changes despite increased IOP, whereas other patients show evidence of glaucomatous changes in the absence of increased IOP. 2,20,21 Ischemia and vascular dysregulation have been implicated in the pathogenesis of GON, and ET-1 has been demonstrated to be a key player in regulation of ocular perfusion and perhaps in the overall pathogenesis of glaucoma.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] However, the role ET-1 plays in different types of glaucoma is unclear [3][4][5][6][7][8][9] and its association with glaucoma severity has not yet been determined. Although some studies have shown that increased plasma ET-1 levels are associated with the development and severity of normal tension glaucoma (NTG) and high-tension primary open-angle glaucoma (POAG), 3,4,9 other studies have shown a lack of association between ET-1 levels and the development of those 2 types of glaucomatous optic neuopathy.…”

Black Currant Anthocyanins Normalized Abnormal Levels of Serum Concentrations of Endothelin-1 in Patients with Glaucoma

“…In fact, previous studies demonstrated that patients with glaucoma, in contrast to the control subjects, have an abnormal hyperactivity of ET-1 in response to vasospastic stimuli such as cold. 58 It has been postulated that an imbalance between vasoconstrictor substances such as 59,60 It was reported that patients with glaucoma who have vasospasm have a higher susceptibility to glaucomatous damage, which could be a consequence of a decreased dilation of blood vessels that properly autoregulate blood flow. 55 If our speculation is correct, BCACs induce normalization of ET-1, and its receptor balance may be beneficial for ocular blood circulation, since an increased ET-1 reactivity could lead to decreased ocular blood flow as indicated above.…”

Two-Year Randomized, Placebo-Controlled Study of Black Currant Anthocyanins on Visual Field in Glaucoma

“…In vivo experiments demonstrated that oral administration of the BCACs significantly improved dark adaptation and video display terminal work-induced transient refractive alteration in healthy human volunteers [15]. In terms of the relationship between ET-1 and the eye, some investigations have shown that ET-1 receptors are present in human uveal tissues [38], retina and ONH [39], suggesting that ET-1 may be implicated in ischemic vascular diseases such as diabetic retinopathy [40], retinal vein occlusion and retinal artery occlusion [41] and glaucoma [42,43,44,45]. Previous studies have shown that statistically significant differences of plasma ET-1 levels exist in glaucoma patients as compared to those in control subjects [12,43,46,47].…”