Petersen J
Universitäts-Augenklinik, Göttingen, Federal Republic of Germany.
Graefes Arch Clin Exp Ophthalmol. 1987;225(6):452-6. doi: 10.1007/BF02334175.
Silicone oil inside the vitreous cavity exerts forces on to the retina as a result of buoyancy, volume displacement, and surface tension. Surface tension rather than viscosity is the key to understanding why the oil seals retinal breaks effectively. The physics of the tamponade was studied quantitatively. Retinal traction can be counteracted by the oil up to a calculated threshold value, depending on the size and shape of the tear, the strength of the surface tension and, most importantly, the distance between the retina and choroid. For a nearly flat retinal hole, the tamponade is very effective. These theoretical results imply straightforward rules for surgery, rules that have been tested in 150 operations. An attempt must be made to fill 100% of the vitreous cavity. Since the air-water boundary has 3 times the surface tension of the water-oil boundary, the most effective procedure is to flatten the retina by means of a fluid-gas exchange and then clamp it in a flat position, implanting the silicone oil. Silicone in the subretinal space or the anterior chamber tends to retract spontaneously, for surface tension causes the smaller bubble to blow up the larger one. Surgical methods are described to make use of it.
玻璃体腔内的硅油由于浮力、体积置换和表面张力而对视网膜施加力。表面张力而非粘度是理解硅油为何能有效封闭视网膜裂孔的关键。对填塞的物理原理进行了定量研究。根据撕裂口的大小和形状、表面张力的强度，以及最重要的是视网膜与脉络膜之间的距离，硅油能够抵消视网膜牵引力直至计算出的阈值。对于近乎扁平的视网膜裂孔，填塞非常有效。这些理论结果为手术提供了直接的规则，这些规则已在150例手术中得到验证。必须尝试将玻璃体腔100%填满。由于气-水界面的表面张力是水-油界面的3倍，最有效的方法是通过液-气交换使视网膜变平，然后将其固定在扁平位置，再植入硅油。视网膜下间隙或前房中的硅油往往会自发回缩，因为表面张力会使较小的气泡膨胀成较大的气泡。文中描述了利用这一现象的手术方法。
