Primary and secondary iris cysts. 
Primary cysts of the iris usually arise from the pigment epithelial layers and are almost always benign, stationary lesions which require no treatment.  Those cysts which are secondary to such agents as trauma or inflammation are, however, characterized by progressive enlargement and visual complications.  The major clinical significance of iris cysts lies in their similarity to iris melanomas.  Cysts should be monitored for enlargement and/or other complications such as inflammation or secondary glaucoma.