IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
DICAAR, Università degli Studi di Cagliari, Cagliari, Italy.
Transl Vis Sci Technol. 2022 Jun 1;11(6):1. doi: 10.1167/tvst.11.6.1.
To investigate the behavior of silicone oil (SiO) at a steady equilibrium and during saccades in pseudophakic highly myopic eyes with posterior staphyloma with and without an encircling band and compare it to behavior in emmetropic eyes. The SiO-retina contact area and shear stress were calculated by computational fluid dynamics.
A numerical model of an emmetropic eye and a myopic eye with and without scleral band underwent a saccade of 50°/0.137 s. The vitreous chamber surface was divided into superior and inferior 180° sectors: lens, pre-equator, post-equator, and macula. SiO-retina contact was evaluated as a function of fill percentages between 80% and 90% for standing, 45° upward tilt, and supine patients. Maximum and average shear stress were calculated.
Overall, SiO-retina contact ranged between 40% and 83%; fill percentage varied between 80% and 95%. Neither the encircling scleral band nor the staphyloma significantly affected the SiO-retina contact area, although the presence of a scleral band proved disadvantageous when gazing 45° upward. The inferior retina-SiO contact remained below 40% despite 95% SiO fill. The SS significantly increased at the scleral band indentation and decreased elsewhere. The staphyloma greatly reduced shear stress at the macula.
The presence of a myopic staphyloma reduces shear stress at the macula but does not alter SiO-retina contact significantly. The apposition of a 360° scleral band may reduce SiO-retina contact at least in some postures and increases the SS at the indentation.
Assessing SiO-retina contact when vitreous chamber geometry changes according to pathologic or iatrogenic modifications allows accurate prediction of real-life tamponade behavior and helps explain surgical outcomes.
研究后葡萄肿性高度近视伴或不伴环扎带的眼在恒定位和扫视期间硅油（SiO）的行为，并将其与正视眼进行比较。通过计算流体动力学计算 SiO-视网膜接触面积和剪切应力。
正视眼和伴或不伴巩膜带的近视眼的数值模型经历了 50°/0.137 s 的扫视。玻璃体腔表面被分为上、下 180°扇形：晶状体、赤道前、赤道后和黄斑。评估了 SiO-视网膜接触情况，填充率在 80%到 90%之间，用于站立、45°向上倾斜和仰卧位患者。计算了最大和平均剪切应力。
总体而言，SiO-视网膜接触范围在 40%到 83%之间；填充率在 80%到 95%之间变化。尽管带环扎带的存在在向上注视 45°时不利，但环扎带或葡萄肿都没有显著影响 SiO-视网膜接触面积。尽管 SiO 填充达到 95%，但下视网膜-SiO 接触仍低于 40%。巩膜带凹陷处的 SS 显著增加，其他部位则降低。葡萄肿大大降低了黄斑处的剪切应力。
近视性葡萄肿的存在会降低黄斑处的剪切应力，但不会显著改变 SiO-视网膜接触情况。360°环扎带的贴合至少在某些姿势下可能会降低 SiO-视网膜接触，并增加凹陷处的 SS。
评估玻璃体腔几何形状根据病理性或医源性改变而改变时的 SiO-视网膜接触情况，可以准确预测实际的填塞行为，并有助于解释手术结果。
