Ziada G, el-Haddad S, Fatouh M, Mustafa H, E-Shemy T, Mahfouz M
Eur J Drug Metab Pharmacokinet. 1985 Oct-Dec;10(4):325-8. doi: 10.1007/BF03189760.
The purpose of this study was to investigate the permeability and clinical significance of the blood-ocular barrier. A new technique using systemic, subtenon, and retrobulbar injections was applied to the study of intraocular penetration of labelled steroid compound. The study was carried out in normal rabbits and in animals with artificially induced intraventional inflammation. It is concluded that there is no blood-vitreous barrier, a vague concept in any case, in the anterior region of the vitreous where free diffusion was observed between the anterior and posterior segments of the eye. High concentration of the labelled steroids was found in the cornea with the peak of activity usually at 30 minutes. However, traces of activity were detectable for up to 4 hours. This indicates the need for a depot long term respiratory form of corticosteroid that would deliver a high concentration of the medication. Local subtenon's and retrobulbar injections resulted in a relatively higher ocular I-125 Cortisol concentration than obtained by systemic route. It is concluded therefore that a high concentration of steroids applied locally will give better and less deletrious effects than systemic administration. Subtenon injection resulted in higher activity in various ocular tissues especially aqueous and vitreous. However, the I-125 Cortisol was rapidly cleared regardless of the route of administration.
本研究的目的是探讨血眼屏障的通透性及其临床意义。一种采用全身、球后和球周注射的新技术被应用于标记类固醇化合物眼内渗透的研究。该研究在正常兔和人工诱导介入性炎症的动物中进行。得出的结论是，在玻璃体前部不存在血 - 玻璃体屏障（无论如何这都是一个模糊的概念），在此处观察到眼的前后节之间可自由扩散。在角膜中发现标记类固醇的高浓度，活性峰值通常在30分钟时出现。然而，在长达4小时内都可检测到微量活性。这表明需要一种长效储库型皮质类固醇呼吸剂型，以便能递送高浓度的药物。局部球周和球后注射导致眼内I - 125皮质醇浓度相对高于全身给药途径。因此得出结论，局部应用高浓度类固醇比全身给药能产生更好且危害更小的效果。球周注射在各种眼组织尤其是房水和玻璃体中产生更高的活性。然而，无论给药途径如何，I - 125皮质醇都迅速清除。
