A fluid or semifluid substance (e.g., silicone oil with or without a perfluorocarbon, or a semifluorinated alkane) intended to be used to compress/unfold the retina (up to weeks/months) to support its reattachment following the operative treatment of severe retinal detachment; it might in addition be intended for transient intraoperative use (e.g., to remove silicone oil residues). Often referred to as a retinal tamponade, it is intended to realign the retina by exerting a force against it without flowing behind it. It is typically removed after a period depending upon clinical findings. It may be supplied in a prefilled syringe or other container. This is a single-use device.