Strength of clear corneal incisions in cadaver eyes

To determine the variation in strength of clear corneal incisions, as demonstrated by degree of incision leakage when challenged by increased intraocular pressure, in relationship to the incision width and length.

Mackool Eye Institute, Astoria, New York.

Clear corneal incisions 3.0 or 3.5 mm in width and from 1.0 to 3.5 mm in length (0.5 mm increments) were studied in human cadaver whole globes. Pressure was applied at the corneal apex or 8.0 mm posterior to the external wound margin to determine the strength of the incision with the application of external force.

Clear corneal incisions of 3.0 or 3.5 mm in width and at least 2.0 mm in length demonstrated substantially greater resistance to incision failure than shorter incision lengths with both apical and posterior applied forces.

Clear corneal incisions 2.0 mm or greater in length demonstrate resistance to leakage comparable to similarly constructed scleral tunnel incisions.