United States or Bouvet Island ? Vote for the TOP Country of the Week !
Portions of the iris angle may remain open while other parts are closed. Where the iris tissue lies in contact with the cornea, the stroma of the iris almost totally disappears. In some cases the iris becomes totally adherent to the cornea. Ciliary Body and Chorioid.
The development of the pale circle which surrounds the disc, particularly in glaucomatous eyes, is due to a very slight recession of the pigment layer of the retina and of the margin of the chorioid at this point with some atrophy, apparently consequent on the beginning retraction of the lamina cribrosa and slightly increased pressure of the nerve fiber layer on the underlying tissues at the margin of the disc.
During the acute attack, the vitreous may become slightly turbid by transudation of serum from the vessel of the ciliary body and the chorioid and may become filled with fibrin. In some chronic cases in which absolute glaucoma is reached the development of small blood vessels in convoluted loops springing from the vessels of the discs has been observed.
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.
Word Of The Day