Congenital Iris Coloboma Repair with Excision of Colobomatous Sphincter Muscle.

Congenital iris colobomas do not usually present a major optical issue until the time of cataract surgery, when an intraocular lens (IOL) is placed in the eye that is roughly half the diameter of the crystalline lens. Leaving the coloboma unrepaired or sutured closed without addressing the sphincter muscle in the coloboma often creates visual challenges for the eye postoperatively. The problem has previously been addressed, in part, with a technique that creates a scissor snip between the normal iris sphincter and the colobomatous iris sphincter, but still requires notable peripheral iris traction and root disinsertion for closure of the defect. The technique presented here removes all iris sphincter from the sides of the coloboma allowing closure of the colobomatous defect without the need to create iridodialyses. In certain cases, the use of iris diathermy can be used to create focal iris contraction to maximize sphericity and centration of the pupil.