In iridocyclitis

Ring synechiae involves all of the pupillary margin and leads to seclusio pupillae and forward bowing of the mid-peripheral iris (iris bombe). At this stage the intraocular pressure becomes elevated and subsequently peripheral anterior synechiae and total posterior synechiae evolve.

When synechiae are incomplete and the pupil is dilated, it takes the appearance of a festoon (festooned pupil).

In severe cases, an inflammatory membrane occludes the entire pupillary aperture (occlusio pupillae).