RT Journal Article SR Electronic T1 Plasma endothelin-1 concentrations in patients with retinal vein occlusions JF British Journal of Ophthalmology JO Br J Ophthalmol FD BMJ Publishing Group Ltd. SP 498 OP 503 DO 10.1136/bjo.82.5.498 VO 82 IS 5 A1 Iannaccone, Alessandro A1 Letizia, Claudio A1 Pazzaglia, Sebastiano A1 Vingolo, Enzo M A1 Clemente, Giovanni A1 Pannarale, Mario R YR 1998 UL http://bjo.bmj.com/content/82/5/498.abstract AB AIMS To investigate whether plasma levels of endothelin-1 (ET-1), a potent vasoconstricting peptide that is crucial in regulating retinal blood flow, were elevated in patients with retinal vein occlusion (RVO). METHODS ET-1 plasma concentrations were determined by radioimmunoassays in a double blind fashion in a group of 18 selected patients with RVO, in 20 healthy age matched non-smoking, normoglycaemic, normotensive control subjects, and in 15 patients with uncomplicated essential hypertension in the same age range. RESULTS Patients with RVO had significantly increased ET-1 plasma levels (14.22 (SD 4.6) pg/ml) compared with both normal subjects (7.90 (1.6) pg/ml; p < 0.05) and hypertensive patients (8.50 (2.9) pg/ml; p <0.05). The highest concentrations of circulating ET-1 were found in patients with RVO of the ischaemic type (16.97 (3.5) pg/ml; p < 0.01; n = 7). Systemic hypertension alone did not account for the observed increase in plasma ET-1 concentrations. CONCLUSIONS These findings raise the possibility that the increased circulating ET-1 levels in patients with RVO may be a marker of the occlusive event, thereby suggesting that ET-1 homeostasis may be relevant to RVO pathogenesis and retinal ischaemic manifestations.