Traumatic iridodialysis is the result of an injury, typically blunt trauma that pulls the iris away from the ciliary body. The resulting deformity appears as a lens-shaped defect at the outer margin of the iris. Patients may present complaining of a “2nd pupil.” As the iris pulls away from the ciliary body, a small amount of bleeding may result. Look closely for associated traumatic hyphema.
Consider etiologies such as penetrating injury to the globe, scleral rupture, IO FB, and lens dislocation causing billowing of the iris.
Management and Disposition
A remote traumatic iridodialysis requires no specific treatment in the emergency department. Recent history of ocular trauma should prompt a diligent slit-lamp examination for associated hyphema or lens dislocation. If hyphema is present, treat it as discussed (see “Hyphema”). Refer cases of iridodialysis for specialty consultation to exclude other injuries; if the defect is large enough to result in monocular diplopia, surgical repair may be necessary.
The examination should carefully exclude posterior chamber pathology and hyphema. Consider bedside ultrasonography to rule out posterior pole injuries (retinal detachment, vitreous hemorrhage, lens dislocation, or FB).
Carefully review the history to exclude penetrating trauma. If the history is unclear, CT scan may be used to exclude the presence of IO FB.
A careful examination includes searching for associated lens dislocation.
Traumatic Iridodialysis. The iris has pulled away from the ciliary body as a result of blunt trauma. A traumatic cataract is also seen. The rosette pattern is classically seen after contusion injuries. It is due to separation of lens fibers around lens sutures. (Used with permission from Brice Critser, CRA, The University of Iowa and EyeRounds.org.)