Department of Ophthalmology, Tulane School of Medicine, Tulane University, New Orleans, Louisiana 70112, USA.
Ophthalmology. 2010 May;117(5):916-20. doi: 10.1016/j.ophtha.2009.09.041. Epub 2010 Jan 15.
To measure variations in diameter and location of Schlemm's canal in vivo by ultrasound biomicroscopy.
Prospective, single-institution, consecutive case series.
Ninety-four patients with and without glaucoma.
Under topical anesthesia, an 80-MHz iUltrasound probe (iScience Interventional, Inc., Menlo Park, CA) placed at the 12-o'clock position was used to measure the canal's diameter and its distance from both the anatomic limbus (corneoscleral junction) and the angle (the base of the canal and the angle of iris insertion).
Diameter and location of the canal were measured relative to gender, age, intraocular pressure, race, diagnosis, previous glaucoma surgery, pachymetry, refraction, lens type, axial length, and keratometry.
The average canal diameter was 121 microm (+/-45 microm). The canal diameter in hyperopes was larger than the canal diameter in myopes (180+/-69 microm vs. 122+/-45 microm; P<0.001). The diameter of Schlemm's canal was smaller in patients with previous glaucoma surgery compared with patients without glaucoma surgery (98+/-20 microm vs. 125+/-4 microm; P<0.01). The mean distance between the angle and Schlemm's canal was found to be smaller in hyperopes than in myopes (281 vs. 335 microm; P = 0.03). The location of the canal in black patients compared with white patients was found to be more posterior from the limbus (659+/-92 microm vs. 624+/-73 microm; P = 0.05). Similarly, canal location in patients with corneal thickness of more than 555 microm was found to be more posterior to the limbus (702 vs. 625 microm; P<0.01) compared with those with thinner corneas.
When measured in vivo with ultrasound biomicroscopy, Schlemm's canal diameter was significantly smaller (121 microm) than demonstrated in previous histopathologic studies.
通过超声生物显微镜活体测量施累姆氏管的直径和位置的变化。
前瞻性、单机构、连续病例系列。
有和没有青光眼的 94 名患者。
在局部麻醉下，使用放置在 12 点钟位置的 80MHz iScience 介入超声探头（iScience Interventional，Inc.，Menlo Park，CA）测量管的直径及其与解剖性角膜缘（角巩膜交界处）和角（管底和虹膜插入角）的距离。
相对于性别、年龄、眼内压、种族、诊断、既往青光眼手术、角膜厚度、屈光、晶状体类型、眼轴和角膜曲率计，测量管的直径和位置。
平均管直径为 121μm（+/-45μm）。远视者的管直径大于近视者（180+/-69μm vs. 122+/-45μm；P<0.001）。既往青光眼手术后患者的施累姆氏管直径小于未行青光眼手术的患者（98+/-20μm vs. 125+/-4μm；P<0.01）。发现远视者的角与施累姆氏管之间的平均距离小于近视者（281μm vs. 335μm；P=0.03）。与白人患者相比，黑人患者的管位置从角膜缘向后更靠后（659+/-92μm vs. 624+/-73μm；P=0.05）。同样，角膜厚度大于 555μm的患者的管位置也比角膜较薄的患者更靠后（702μm vs. 625μm；P<0.01）。
通过超声生物显微镜活体测量，施累姆氏管直径（121μm）明显小于先前的组织病理学研究。
