Posterior lip traction caused by intravitreal gas.

Traction on the posterior edge of a large tear may be an irreparable consequence of an intraocular gas tamponade used in the first instance to treat the tear. In two of three patients treated with octofluorocyclobutane (C4F8) and perfluoromethane (CF4), redetachment of a retinal tear occurred as a result of traction on the posterior edge of the tear when, prior to the operation, the posterior edge seemed to be free of any traction. With redetachment, a membrane became visible between the anterior and posterior lips of the tear. The membrane was probably posterior hyaloid augmented by cellular proliferation. The gas bubble, which had been intended to press the retina against the pigment epithelium, probably brought the detached posterior hyaloid into contact with the retina as well, and an adhesion between the hyaloid and retina formed.