han of an active or arterial congestion. The vessels of the ciliary
process, which are larger and more tortuous in adults of advanced years
than in the young, become enormously distended, causing almost complete
obliteration of the perilental space. They press against the root of the
iris and the equator of the lens, forcing them forward. There is edema
of the ureal tract, apparently from transudation of serum. Many small,
and sometimes rather large hemorrhages may occur. There is but little
small cell infiltration, indicating almost total absence of what is
ordinarily recognized as true inflammation. It is probable that the
secretion from the glandular zone of the ciliary body is increased.

On subsidence of the congestion, as after miotics or iridectomy, the
tissues may return to very nearly a normal condition. The iris recedes
from contact with the ligamentum pectinatum and cornea and the
filtration angle is again open. In some cases the iris becomes adherent
to the head of the ciliary processes and, when atrophy of the ciliary
body occurs, is drawn backward at the base of the iris by the receding
tissues. If the hypertension persists or is repeated at varying periods,
a slow atrophy of the uveal tract sets in. Eventually the ciliary body
becomes very much reduced in thickness, is flattened out, the ciliary
processes reduced in size and the blood vessels disappear or are reduced
much in caliber. Those that persist possess walls that are much
thickened. This is particularly true of hemorrhagic glaucoma.

In advanced absolute glaucoma the chorioid may become reduced to a very
thin membrane consisting of connective tissue and pigmented cells,
scarcely distinguishable even by moderate powers of the microscope.
Atrophy is marked in the vicinity of the venae vorticosae. Czermak and
Birnbacher describe proliferation of the endothelium of the large veins
with contraction and obliteration of their lumen.

_Optic Nerve and Retina._ In the acute form the retina and optic nerve
present the same condition that is present in the vascular tunic;
namely, that of venous stasis with the consequent edema. Frequently
minute hemorrhages occur in the retina, particularly in violent acute
attacks. Cupping of the discs slowly develops, causing more or less
stretching of the nerve fibers over the edge of the cup. The gradual
diminution of the field of vision is due in greater part to death of
peripheral nervous elements of the retina, those