View source for Persistent pupillary membrane


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==Overview==

'''Persistent pupillary membrane (PPM)''' is a condition of the [[eye]] involving remnants of a fetal membrane that persist as strands of tissue crossing the [[pupil]].  The pupillary membrane in [[mammal]]s exists in the [[fetus]] as a source of blood supply for the [[lens (anatomy)|lens]].  It normally atrophies from the time of birth to the age of four to eight weeks.<ref name=Gelatt_1999>{{cite book|author=Gelatt, Kirk N. (ed.)|title=Veterinary Ophthalmology|edition=3rd ed.|publisher=Lippincott, Williams & Wilkins|year=1999|id=ISBN 0-683-30076-8}}</ref>  

PPM occurs when this atrophy is incomplete. It generally does not cause any symptoms. The strands can connect to the [[cornea]] or lens, but most commonly to other parts of the [[iris (anatomy)|iris]].  Attachment to the cornea can cause small corneal opacities, while attachment to the lens can cause small [[cataract]]s.  Using topical [[atropine]] to dilate the pupil may help break down PPMs.

In dogs, PPM is inherited in the Basenji but can occur in other breeds such as the Pembroke Welsh Corgi, Chow Chow, Mastiff, and English Cocker Spaniel.<ref name=Gelatt_1999/>  

It is also rarely seen in cats, horses, and cattle.

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{{Eye pathology}}
[[Category:Ophthalmology]]
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