Schalnus R W, Ohrloff C, Magone T
Zentrum der Augenheilkunde, Universität Frankfurt/Main.
Ophthalmologe. 1995 Jun;92(3):289-92.
An intact posterior capsule between aqueous and vitreous may act as a barrier to substances of low and high molecular weight, e.g., prostaglandins, hyaluronic acid, or the angiogenic factor. After phacoemulsification followed by posterior YAG capsulotomy, an increased diffusion rate of such molecules into the vitreous and increased permeability of blood aqueous barrier (BAB) may occur. These barriers were quantified in eyes that underwent YAG capsulotomy after sulcus or intracapsular IOL implantation in order to determine the safest surgical procedure with respect of maintenance of these barriers.
Between 2 to 6 h after topical fluorescein application, the time-dependent decrease in dye concentration ratio between aqueous and anterior vitreous leads to the diffusion rate D(av) [10(-3)min-1] between aqueous and vitreous; D(av) was evaluated fluorophotometrically before and 3 weeks after capsulotomy (3 to 5 mm) in human eyes of each group. In order to quantify BAB function, aqueous laser flare was measured in eyes with sulcus and capsular fixation of IOL before, 3 h, and 3 weeks after YAG capsulotomy.
After YAG surgery D(av) increased 2.7-fold (P < 0.001) in eyes with a sulcus implant compared to the values obtained in the group that had an intracapsular PCL. Aqueous laser flare was increased to 140% (P < 0.001) in eyes with sulcus fixation and to 95% (P < 0.001) in eyes with capsular fixation of PCL. Laser flare values became normal 3 weeks after laser treatment (P > 0.05).
Intracapsular PCL implantation more effectively maintains the protective aqueous vitreous barrier and BAB after posterior capsulotomy than sulcus implantation. This possibly reduces the incidence of cystoid macular edema (diffusion of prostaglandins), retinal detachment (loss of hyaluronic acid of the vitreous), endophthalmitis (spread of bacteria) or rubeosis iridis (angiogenic factor) after YAG capsulotomy.
房水和玻璃体之间完整的后囊可能对低分子量和高分子量物质起到屏障作用，例如前列腺素、透明质酸或血管生成因子。在超声乳化联合后囊钇铝石榴石激光切开术后，此类分子向玻璃体的扩散速率可能增加，血-房水屏障（BAB）的通透性也可能增加。对在睫状沟或囊内植入人工晶状体后接受钇铝石榴石激光切开术的眼睛中的这些屏障进行了量化，以确定在维持这些屏障方面最安全的手术方法。
在局部应用荧光素后2至6小时，房水和前玻璃体之间染料浓度比随时间的下降导致房水和玻璃体之间扩散速率D(av) [10(-3)分钟-1]；在每组人眼中，在钇铝石榴石激光切开术（3至5毫米）前和术后3周通过荧光光度法评估D(av)。为了量化血-房水屏障功能，在钇铝石榴石激光切开术前、术后3小时和3周，对人工晶状体睫状沟固定和囊袋固定的眼睛测量房水激光散射。
与囊内植入后房型人工晶状体组相比，钇铝石榴石激光切开术后，睫状沟植入人工晶状体的眼睛中D(av)增加了2.7倍（P < 0.001）。睫状沟固定的眼睛中房水激光散射增加到140%（P < 0.001），后房型人工晶状体囊袋固定的眼睛中增加到95%（P < 0.001）。激光治疗3周后激光散射值恢复正常（P > 0.05）。
后囊切开术后，囊内植入后房型人工晶状体比睫状沟植入更有效地维持保护性房水-玻璃体屏障和血-房水屏障。这可能会降低钇铝石榴石激光切开术后黄斑囊样水肿（前列腺素扩散）、视网膜脱离（玻璃体透明质酸流失）、眼内炎（细菌传播）或虹膜新生血管（血管生成因子）的发生率。
