Normal and reactive LNs appear to exhibit hilar vascularity or avascularity
Milder forms of FEVR may manifest with peripheral avascularity
accompanied by vitreoretinal adhesions, venovenous anastomoses, increased vascular branching, and V-shaped retinochoroidal degeneration.
An intimate regulation of epithelial cell proliferation is the key to maintain corneal avascularity
. Animal models of increased epithelial proliferation such as in Destrin-mutant CORN1 mice also show spontaneous corneal neovascularization [58, 59].
In the case of diabetic subjects, long-term hyperglycemia can trigger inadequate blood supply that eventually leads to blood-retina barrier breakdown, high vascular permeability, and avascularity
. Thus, numerous angiogenic related cytokines, such as hypoxic-inducible factors (HIFs), vascular endothelial growth factor (VEGF), and erythropoietin are overexpressed to raise blood flow of the ischemic tissue, to increase vascular permeability, and to maintain the perfusion pressure in the tissue .
However, as shown in Figure 1, the temporal area is larger, and it is mainly responsible for the retinal avascularity
and has spatial closeness with the macula.
In an earlier study, (21) researchers in our lab used orthogonal polarization spectral imaging to define and report mean areas of flap avascularity
, areas of stasis exhibiting vessels without flow, and unaffected areas showing vessels with blood flow.
(1) Angiography can have a variable appearance, ranging from avascularity
to intense hypervascularity that can be seen with an arteriovenous malformation or hemangiopericytoma.
is a risk factor, which should be given primary consideration and the presence of teeth in the line of fracture are others.
Barr (2004) postulated avascularity
to arise from the compression and attrition of the supraspinatus tendon in a narrowed subacromial space.
* Relative avascularity
, which limits fluid absorption.
Although radical debridement, acute compression, and lengthening are recommended for nonunion with bone defects due to osteomyelitis in the literature [12, 13], we preferred additionally bone grafting to treat nonunion and shortening for this extreme hemophilia patient because of the lack of biological factors, such as avascularity
of the bone end atrophic pseudarthrosis formation.
Treatment for air sac trematodes is especially difficult because of the relative avascularity
of the air sacs.