Among the common conditions which give rise to dispersement of pigment in the eye are: (1) glaucoma, (2) trauma, (3) inflammation and (4) necrotic melanosarcoma.
The fate of dispersed pigment may be :
Phagocytosis by lymphocytes. Lymphocytes, unlike polymorphonuclear leukocytes, have a tendency to agglutinate and form small masses of cells. On reaching the anterior chamber these masses precipitate to the dependent part and are seen clinically deposited on the posterior surface of the cornea. They are first grayish in color and their pigment inclusions inconspicuous. But later as the lymphocytes disintegrate, the precipitate becomes smaller and their pigment elements more conspicuous until finally these deposits appear as unadulterated pigment granules. Such is the common fate of pigment set free in uveitis.
Distribution in various places as free pigment. Pigment granules have a certain tendency to agglutinate, and any such agglutinated masses may, by virtue of their
REESE AB. PIGMENT DEPOSIT IN THE CONTRACTION FURROWS OF THE IRIS. Arch Ophthalmol. 1929;2(1):27-29. doi:10.1001/archopht.1929.00810020030002