Expandable silicone rubber implants, used for scleral buckling procedures in retina detachment surgery, were evaluated in in vitro experiments. The devices deflated within a matter of minutes when they were inflated with air, but remained practically unchanged in size for over two months, when expanded with physiological saline solution and compressed under relatively low pressures (up to 200 mm Hg). When the same saline solution-expanded implants were compressed under higher pressures (400 to 1,000 mm Hg), they decreased in volume by 30% in two months. The range of pressure required to expand different sizes of implants, as well as the range of volumes which may be safely injected, were also determined.
Refojo MF, Banuelos A. Expandable Silicone Implants for Scleral BucklingII. Experiments in vitro. Arch Ophthalmol. 1973;90(2):127-130. doi:10.1001/archopht.1973.01000050129012