Very rare. Often associated with an aneurysmal dilation of the ductus arteriosus, resulting in a massive left-right extracardiac shunt.

Anesthetic implications: 

permanent bilateral areactive mydriasis, photophobia

References : 

-         Yamamoto T, Schmidt-Niermann M, Schindler E.
Bilateral congenital iris sphincter agenesis diagnosed after massive bleeding episode during repair of aneurysmal dilation of the patent ductus arteriosus: a case report.
A&A Case Reports 2016; 8: 155-7.

Updated: June 2018