Accessory cells in vessels of the paranatal human retina
D. G. Cogan and T. Kuwabara
Retinas of the paranatal period contain two types of cell clusters that are
generally believed to play a role in the developing vasculature. The more
posterior cluster consists of angioblastic cells, which undergo
lumenization to form the definitive vessels. Anterior to this cluster and
separated from it by a distinct boundary are clusters of spindle cells
extending a variable distance toward the periphery. These clusters of
spindle cells maintain a fixed position relative to the angioblastic
masses, without any admixture of the two. The precise function of the
spindle cells in the vascularizing process has been a subject of
controversy. We found evidence to identify them as glia and to suggest that
their role is to provide an energy source for the developing retina as the
hyaloid vessels recede and until the retinal vessels take over this
function. It further appears that congenital failure of the vessels to
develop may result in a persistence of these spindle cells, in the form of
hyperplastic glia in the inner layers of the retina. Our study included
normal eyes from full-term and premature infants and eyes from patients
with retinopathy of prematurity (oxygen-related retinopathy), anencephaly,
and other congenital anomalies.
