The Canabrava Ring, an open ring-shaped pupil expander for cataract surgery associated with iris colobomata: a case report.

In this report, we describe a new pupil expander device that was used to obtain adequate pupil dilation and centering in a patient with an iris coloboma. Specifically, we describe the case of a patient with an iris coloboma; a Malyugin ring was inserted to facilitate dilation during phacoemulsifi-cation surgery. One of the scrolls did not engage which resulted in an uneven distribution of forces and an eccentric pupil. A Canabrava Ring was then implanted that promoted effective pupillary dilation and remained stable and effective throughout the surgical procedure.