A trocar assembly and associated methods are shown. Using example devices and methods shown, a surgeon may insert an obturator with a blade portion and a tube portion of a cannula into tissue such as eye tissue. In one state, the blade portions are wider than or equal to outer diameters of the tube portions. This facilitates an incision in tissue such as eye tissue that is wide enough to allow the tube portions to pass through. Because the blade portions are adapted to deform, they may be withdrawn through the inner diameter of the tube portions.