Congenital mydriasis associated with megacystis microcolon intestinal hypoperistalsis syndrome.

ABSTRACT

We report a case of congenital mydriasis in a neonate with megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS). Pilocarpine testing and gastrointestinal pathology in our patient suggest that the mydriasis is due to an underlying smooth muscle myopathy of the iris sphincter muscle. These findings may have important implications regarding the pathogenesis of MMIHS.