Olsen T W, Edelhauser H F, Lim J I, Geroski D H
Department of Ophthalmology, Emory University, Atlanta, GA 30322, USA.
Invest Ophthalmol Vis Sci. 1995 Aug;36(9):1893-903.
To determine the in vitro permeability of human sclera to compounds varying in molecular weight. To evaluate the effects of age, cryotherapy, transscleral diode laser, and surgical thinning on scleral permeability.
Scleral tissue from 97 human eye bank eyes was tested individually in a two-chamber Ussing apparatus with the following hydrophilic radiolabeled compounds on one side of the chamber: 5-fluorouracil, sucrose, dexamethasone, methotrexate, inulin, and three separate dextran polymers (MWt = 10,000, 40,000, and 70,000). Scleral hydration levels were obtained on 20 more scleral specimens. Additional groups of scleral specimens were treated with either a cryotherapy probe, a transscleral diode laser retinopexy probe, or partial thickness lamellar dissection, and specimens were mounted in the Ussing chambers for testing. Scleral tissue was digested to measure the amount of radioactivity present. Scleral sections were examined with electron microscopy.
Scleral hydration was maintained during the perfusion. The mean scleral permeability (cm/second x 10(-6) +/- SD) was established for each of the above compounds. Age, cryotherapy, or diode laser treatment did not alter permeability or ultrastructure of the sclera. Surgical thinning significantly increased the scleral permeability to dexamethasone (P = 0.011) and methotrexate (P = 0.037).
This study establishes baseline human scleral permeability to a series of hydrophilic compounds with various molecular weights. Age, cryotherapy, and diode laser treatment do not alter the permeability or ultrastructure of the sclera, whereas surgical thinning significantly increases permeability.
确定人巩膜对不同分子量化合物的体外通透性。评估年龄、冷冻疗法、经巩膜二极管激光以及手术变薄对巩膜通透性的影响。
在双室Ussing装置中对97只人眼库眼球的巩膜组织进行单独测试，在腔室一侧放置以下亲水性放射性标记化合物：5-氟尿嘧啶、蔗糖、地塞米松、甲氨蝶呤、菊粉以及三种不同的葡聚糖聚合物（分子量分别为10,000、40,000和70,000）。对另外20个巩膜标本测定巩膜水化水平。将额外的巩膜标本组分别用冷冻疗法探头、经巩膜二极管激光视网膜固定探头或部分厚度板层剥离进行处理，然后将标本安装在Ussing腔室中进行测试。消化巩膜组织以测量其中存在的放射性量。用电子显微镜检查巩膜切片。
灌注过程中巩膜水化得以维持。确定了上述每种化合物的平均巩膜通透性（厘米/秒×10⁻⁶±标准差）。年龄、冷冻疗法或二极管激光治疗均未改变巩膜的通透性或超微结构。手术变薄显著增加了巩膜对地塞米松（P = 0.011）和甲氨蝶呤（P = 0.037）的通透性。
本研究确立了人巩膜对一系列不同分子量亲水性化合物的基线通透性。年龄、冷冻疗法和二极管激光治疗不会改变巩膜的通透性或超微结构，而手术变薄则会显著增加通透性。
