Relative strength of cataract incisions in cadaver eyes

We evaluated the strength of various incisions used in cataract surgery in cadaver eyes. Fluid was forced into the eye through a paracentesis incision and measured via a second paracentesis incision connected to a pressure transducer. In four eyes with the limbal, two-step procedure and radial sutures, leakage from the wound was seen at 100 mm Hg to 120 mm Hg, and iris prolapse through the wound occurred at 160 mm Hg to 400 mm Hg. In three eyes with the scleral tunnel two-step procedure, no prolapse was observed at pressures up to 400 mm Hg, although leakage was observed in two eyes at 400 mm Hg. In two eyes with the three-step procedure with an internal corneal lip, no leakage or prolapse was observed at pressures up to 400 mm Hg or upon manipulation of the wound at various pressures. In an additional evaluation of four eyes with the three-step procedure, no leakage or prolapse was observed with compressed air at pressures over 2,000 mm Hg. A three-step incision with an internal corneal lip may provide a more pressure resistant wound than a two-step limbal or scleral tunnel incision.