Fig. 13. A. The incision is made at the anterior limit of the surgical limbus to minimize trauma to the anterior chamber angle and to prevent iris adhesions to the wound. A single pass of the disposable knife is made to keep the incision uniplanar. A chord length of 3 mm allows a snug fit of the irrigation aspiration handpieces without excess fluid leakage. B. The plane of the incision is parallel to the iris so that it is partially self-sealing. An incision that is too perpendicular to the cornea will not be self-sealing and is more prone to detachment of Descemet's membrane with instrument insertion.