Intravitreal longevity of three perfluorocarbon gases

Three gases, perfluoromethane, perfluoroethane, and perfluoropropane (CF4, C2F6, and C3 F8, respectively) were studied for their possible value as intravitreal tamponades in retinal surgery. The gases expand and have intraocular longevities that increase with the length of the carbon chain. A 0.4-cc injection of CF4, remained in the eye six days, twice as long as an equivalent amount of air; C2F6 remained 16 days, more than four times as long as air; and C3F8 remained 28 days, nine times as long as air and four times as long as sulfur hexafluoride.