Br J Ophthalmol 1998;82:498-503 ( May )
Plasma endothelin-1 concentrations in patients with retinal vein
occlusions
Alessandro Iannaccone,a
Claudio Letizia,a b
Sebastiano Pazzaglia,a
Enzo M Vingolo,a
Giovanni Clemente,b
Mario R Pannaralea
a Institute of Ophthalmology, University La Sapienza,
Rome, Italy, b Institute of
Internal Medicine II, University La Sapienza, Rome, Italy
Correspondence to: Alessandro Iannaccone, MD, University of Tennessee Department of
Ophthalmology, Coleman Building, Suite D-228, 956 Court Avenue,
Memphis, TN 38163, USA.
Accepted for publication 9 December 1997
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).
METHODSET-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.
RESULTSPatients 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.
CONCLUSIONSThese 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.
Keywords:
endothelin-1;
hypoxia;
ischaemia;
retinal vein
occlusion;
thrombogenesis;
venous stasis
© 1998 by British Journal of Ophthalmology
