<prompt> Persistent pupillary membrane originates fromCollaretteAngle of ant. chamberAround pupilRoot of iris  <response>: Ans. a CollaretteRef: Paediatric Ophthalmology by Wright and Speigel, p. 444PPM is the most common developmental abnormality of the iris. They are believed to the vestiges of precursor vessels and associated structures derived from tunica vasculosa lentis.The formation of a PPM is a normal embryological process and starts at the Iris Collarette thickest part of the iris. 