Anderson N J, Woods W D, Kim T, Rudnick D E, Edelhauser H F
Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA, USA.
Arch Ophthalmol. 1999 Feb;117(2):225-32. doi: 10.1001/archopht.117.2.225.
To characterize the uptake, washout, and metabolism of lidocaine hydrochloride in the iris/ciliary body and cornea.
Iris/ciliary body uptake of lidocaine hydrochloride was measured by incubating human and rabbit irides in radiolabeled carbon 14-1% lidocaine hydrochloride for 2 to 60 minutes. Washout was determined by incubating the iris in 14C-1% lidocaine hydrochloride for 5 minutes and transferring the iris to a series of wells. The wells contained a common intraocular irrigating solution of essential ions, glucose, and glutathione buffered with bicarbonate (an enriched balanced salt solution [BSS PLUS]), which is similar to aqueous humor. Corneal uptake was measured by exposing the endothelial surface to 14C-1% lidocaine hydrochloride for 5 or 15 minutes. Corneal washout was performed after 5-minute exposure to 14C-1% lidocaine hydrochloride using a 2-chambered diffusion apparatus. Samples of the iris, cornea, and BSS PLUS washout solution were analyzed by high-performance liquid chromatography and liquid scintillation spectrometry.
In vitro iris/ciliary body uptake of 14C-1% lidocaine hydrochloride follows a logarithmic curve, with 50% to 60% of maximum lidocaine hydrochloride uptake present at 5 minutes. There was no difference in uptake between human, albino rabbit, and pigmented rabbit irides. Washout of lidocaine from the iris occurs with a halflife of 8 to 9 minutes. Corneal uptake of lidocaine was greater after incubation for 15 vs. 5 minutes. The washout of lidocaine from the cornea had a half-life of 5 minutes. Results of high-performance liquid chromatography confirmed that there were no metabolites or breakdown products in the iris, cornea, or washout solution.
Lidocaine is taken up quickly by the iris/ ciliary body and cornea and rapidly removed from these tissues after BSS PLUS washout. Irrigation during phacoemulsification seems to limit lidocaine exposure to the ocular tissues, resulting in a short duration of anesthesia. Lidocaine is not metabolized or broken down by the iris or cornea during this short period.
描述盐酸利多卡因在虹膜/睫状体及角膜中的摄取、清除及代谢情况。
通过将人和兔的虹膜在放射性标记的碳14 - 1%盐酸利多卡因中孵育2至60分钟，来测定虹膜/睫状体对盐酸利多卡因的摄取。通过将虹膜在14C - 1%盐酸利多卡因中孵育5分钟，然后将虹膜转移至一系列孔中，来测定清除情况。这些孔中含有一种常见的眼内冲洗液，其为含有必需离子、葡萄糖和经碳酸氢盐缓冲的谷胱甘肽的平衡盐溶液（一种强化平衡盐溶液[BSS PLUS]），类似于房水。通过将角膜内皮表面暴露于14C - 1%盐酸利多卡因5或15分钟来测量角膜摄取。在暴露于14C - 1%盐酸利多卡因5分钟后，使用双室扩散装置进行角膜清除。通过高效液相色谱法和液体闪烁光谱法对虹膜、角膜和BSS PLUS冲洗液样本进行分析。
体外虹膜/睫状体对14C - 1%盐酸利多卡因的摄取呈对数曲线，在5分钟时达到最大盐酸利多卡因摄取量的50%至60%。人、白化兔和有色兔的虹膜在摄取方面没有差异。利多卡因从虹膜清除的半衰期为8至9分钟。孵育15分钟后角膜对利多卡因的摄取比孵育5分钟时更高。利多卡因从角膜清除的半衰期为5分钟。高效液相色谱法的结果证实，在虹膜、角膜或冲洗液中没有代谢物或分解产物。
利多卡因可被虹膜/睫状体及角膜快速摄取，并在BSS PLUS冲洗后迅速从这些组织中清除。超声乳化术中的冲洗似乎限制了利多卡因与眼组织的接触，导致麻醉持续时间较短。在此短时间内，利多卡因不会被虹膜或角膜代谢或分解。
