fibrovascular connective tissue that proliferates in the anterior layers of the peripheral cornea in inflammatory corneal disease, particularly trachoma in which the pannus involves the superior cornea. Three forms occur:
pannus crassus (thick), in which there are many blood vessels and the opacity is very dense;
pannus siccus (dry), pannus with dry, glossy surface; and
pannus tenuis (thin), in which there are few blood vessels and the opacity is slight.