Why do some vitrectomy procedures use silicone oil and others a gas like c3f8?

Retinal detachments: Gas is usually injected into the eye after vitrectomy performed for primary retinal detachments . Different gases have different retention times. Silicone oil is usually reserved for recurrent detachments especially when associated with fibrosis causing traction referred to as pvr.

To attach the retina: Silicone oil and fluorocarbon gases are used to tamponade the retina against the choroid and to facilitate reattachmemt.

See below: Gas like c3f8 dissolve away after a few weeks. Silicone oil does not, such that another eye surgery is required to remove the silicone oil. A retina that needs a longer duration of tamponade, such as tractional retinal detachment, may need oil. Vitrectomy for macula hole should only need gas (sf6 gas lasts less long than c3f8).