A quantitative animal model of traumatic iridodialysis

The impact velocities and kinetic energies necessary to create a particular form of ocular injury, traumatic iridodialysis, were quantitatively studied by experimentally traumatizing enucleate porcine eyes. Thicknesses and tensile strengths of porcine and human iris tissue were measured in order to allow for predictions of human results to be made from the animal model. Application of blunt trauma at an impact angle of 30-35 degrees with respect to the iris plane with striking of the eye at the corneolimbal junction was found to optimize tearing of the iris from the root. Using this vector, the minimum velocity for the creation of an iridodialysis at least 6 mm in length in the human eye is predicted to be 14 m/sec for impact with a projectile of 13.4 g with a 6 mm diameter tip.