way of the minute channels which permit
the passage of small nerve twigs, and enters the epithelial cell layer.
The fluid finds its way between the epithelial cells in the deeper
layers, apparently being taken into some of the superficial cells by
imbibition. Some of the swollen surface cells open spontaneously and
discharge their contents, others drop off. The process causes a
roughening of the surface of the cornea and produces a faint haziness.
There is another form of haziness that develops on sudden rise in
tension and completely disappears on subsidence of the tension. This is
due, as has been shown by V. Fleischl (Sitzungsberichle d. Weiner Akad.
d. Wissensch, 1880) and others, to increased tension on the fibrillae of
the cornea, a double refraction being induced. In cases of long
continued increase of tension minute permanent vesicles form in the
epithelial layers, particularly in the superficial portion. Anaesthesia
of the cornea develops, due to pressure on the nerve fibers that are
distributed to the epithelium, the compression probably occurring along
the course of the long ciliary nerves, from which the corneal nerves are
derived, as they pass between the choroid and the unyielding sclera
(Collins & Mayou).

In advanced cases of glaucoma after the congestive period has subsided
the cornea becomes somewhat condensed, the lymph spaces contracted; a
condition of sclerosis obtains. Alteration in the shape of the cornea
occurs only rarely in adult life. When it does occur it takes place in
corneae that have suffered from keratitis. The alteration is usually in
the form of ectasiae. In infancy and early youth (buphthalmia) the cornea
may become uniformly enlarged and globular. Often, however, the
enlargement of the cornea is irregular. Increase in tension may produce
fissures in Descemet's membrane. These occur more frequently in the
cornea that have suffered a change in shape, as in buphthalmos. Gaps
occur in the elastic membrane which become covered by endothelium. Some
cloudiness may be seen in the corneal lamellae adjacent to these
fissures, in some cases due evidently to the filtration of aqueous humor
through defective endothelium. Prolonged high intra-ocular tension may
be accompanied, particularly in cases of secondary glaucoma, by
vesicular and bullous keratitis.

In acute glaucoma the sclera appears to be edematous and slightly
thickened. As the disease progresses the sclera becomes denser than
normal