We describe a method for recognizing and managing wound gape of the internal aspect of a scleral tunnel incision. The apposition of the cataract internal incision can be adequately assessed with the use of a gonioprism during and after surgery. With self-sealing tunnel incisions, even though the external incision may be well sealed either with or without the use of a suture, the internal incision may be inconspicuously gaping. When an internal incision gapes open, it takes on the appearance of an elongated oval opening by gonioscopy, a process we have termed fishmouthing. Often fishmouthing can be closed by rapidly deepening the anterior chamber with balanced salt solution through the paracentesis incision; if this is unsuccessful, a limbal suture may be required. Assessment of the internal incision with a gonioprism and management of internal incision fishmouthing is an important method to ensure wound stability and minimize surgically induced astigmatism.