European arteriovenous sheathotomy trial (EAST) – an update
Carsten H. Meyer1, U. Mester2,
P. Kroll1
(1Marburg, 2Sulzbach) for the EAST-study
Branch retinal vein occlusion (BRVO) usually
occur due to a thrombosis at the arteriovenous (AV) crossing. An arteriosclerotic
retinal artery may compress the adjacent retinal vein within the surrounding
adventitial sheath. A surgical decompression may eliminate this primary
cause improving the perfusion and retinal function in selected patients.
The effectiveness of this new treatment approach is currently investigated
in two prospective studies at 10 European centers including Germany, Spain
and Austria. EAST I compairs the natural course with surgical intervention
by vitrectomy including sheathotomy.
The study has been approved by the ethical commity, the design includes
106 eyes for each arm of the study and the recruitment has started in
the fall of 2004. As most BRVOpatients require surgery, the recruitment
for EAST I is limited, therefore the investigators added a second prospective
study. EAST II compairs two surgical subgroups (vitrectomy including ILM-peeling
with or without an additional sheathotomy) in 218 patients. The study
design is currently investigated by the ethical commity and a start of
this study is planned for the fall 2005. Both pospective randomized trials
may demonstrate the benefit or disadvantage of AV-sheathotomy in patients
with BRVO.