As demonstrated in our cases, SO retention sutures offer a method to prevent SO from entering the anterior chamber and touching the corneal endothelium in eyes with iris loss. The surface tension of SO in water, also called the silicone oil/water interface surface tension, is considered high (50 erg/cm2), although not as high as the gas/water interface surface tension (70 erg/cm2).8 The sutures take advantage of the high SO-aqueous interface surface tension.8,9 This interfacial tension, a result of both van der Waals and polar bonding forces, helps SO maintain a spheroidal shape in the eye. These forces are not only able to prevent the suture from breaking the surface of the silicone globule but are strong enough to overcome the low buoyancy force of the SO. This phenomenon was demonstrated by ultrasound biomicroscopic images of our patients in the supine position. The sutures enhance the natural barrier that exists between the oil and the aqueous. Because the sutures rely on an intact SO-aqueous interface, success in using this technique would not be expected in an eye with an overfill of SO and/or inadequate aqueous production (ie, hypotony). As surgeons gain experience with this technique, a larger multicenter study can be performed to elucidate the factors contributing to the success or failure of SO retention sutures.