Hemi-central retinal vein occulsion. Pathogenesis, clinical features, and natural history
S. S. Hayreh and M. S. Hayreh
A two-trunked central retinal vein (CRV) in the anterior part of the optic
nerve may persist as a congenital abnormality in a certain proportion of
humans. One of the two trunks, like the CRV, may get occulded in the optic
nerve to produce hemi-CRV occulsion (hemi-CRVO). It is shown that hemi-CRVO
is a distinct entity, clincially and pathogenetically closely related to
CRVO, and unrelated to branch retinal vein occlusion because of fundamental
differences between the two. Hemi-CRVO clinically presents as either venous
stasis retinopathy (VSR) or as hemorrhagic retinopathy (HR), usually
involving one half of the retina, although ocassionally it may involve one
third to two thirds of the retina. The clinical features of VSR and HR
caused by hemi-CRVO are identical to those caused by CRVO. The primary
object of this article is to identity hemi-CRVO, a not uncommon condition,
and to describe its main clinical features.
