小梁切除术术中房水滤过量与术中及术后早期眼压无关

目的 测量小梁切除术术中房水滤出量,并分析其与术中眼压和术后早期眼压之间的关系。设计 前瞻性观察性研究。研究对象 2009年12月-2010年8月初次接受小梁切除术的82例（82眼）青光眼患者。方法 （1）将不同体积的生理盐水加到泪液检测滤纸条上的指定位置,然后观察滤纸吸水长度与液体量之间的关系。（2）前瞻性纳入初次小梁切除术的青光眼患者,术者遵统一程序行标准小梁切除术,关闭巩膜瓣前房注水稳定后采用Tonopen测量术中眼压。术中在关闭巩膜瓣,前房注水后60 s将泪液检测滤纸条置于巩膜瓣口处测量房水滤出量,持续80 s。分析术中滤过量与术中眼压及术后第1日及第7日眼压之间的关系,并观察术后滤过泡隆起度、范围及并发症情况。主要指标 滤纸湿线长度,术中及术后早期眼压,滤过泡情况。结果 滤纸吸水长度与液体量具有显著相关性,液体的体积可根据滤纸上湿线的长度通过以下公式计算：吸液体积（μl）=1.0434×吸液长度（mm）+2.4086（R2= 0.97）。82例患者（82眼）术前眼压（32.3±9.0）mmHg。根据术中滤纸吸水长度,将患者分为3组：第一组患者的吸水长度≤5 mm（n=46）,第二组6~10 mm（n=18）,第三组≥11 mm（n=18）。三组患者术中眼压分别为（13.9±8.3）mmHg、（12.1±5.4）mmHg、（12.1±6.5）mmHg（P=0.543）。术后第1天三组的眼压分别为（13.3±7.9）mmHg、（12.7±7.3）mmHg、（15.9±9.0）mmHg;术后1周,三组眼压分别为（12.2±6.9）mmHg、（10.7±5.6）mmHg、（13.1±8.1）mmHg,三组间术后早期眼压及滤过泡情况差异均无统计学意义（P均>0.05）。术后未观察到浅前房等其他并发症。结论 滤纸吸水长度与滤出液体量具有显著相关性。小梁切除术术中的滤出量可通过泪液检测滤纸条定量测量。但不能通过术中滤过量这个因素直接判定术后早期的眼压。（眼科, 2014, 23： 94-98）     

牵拉力对人小梁网细胞活性及房水流出调节功能影响的实验研究

 目的 观察强机械牵拉力作用下，人小梁网细胞活性及房水流出调节相关基因表达的改变。设计 实验研究。 研究对象 人小梁网细胞。方法 依据牵拉力作用时间将原代培养的小梁网细胞分为0 h对照、12 h、24 h三组。采用FLEXCELL力学加载设备对体外培养的人小梁网细胞施加最大延伸比例为22%的机械牵拉力。用流式细胞学的方法检测各组小梁细胞的凋亡比率，采用蛋白印迹法检测细胞存活相关蛋白的表达，用定量聚合酶链式反应（qPCR）检测与房水流出调节相关的15个基因在牵张力作用下的表达量，并比较实验组与对照组间的差异。主要指标 小梁网细胞凋亡率、整合素-Fak信号通路相关分子、房水流出调节相关的15个基因的表达量。结果 在牵拉力作用后，对照组、12 h组、24 h组的凋亡率分别为0.71%±0.18%、0.77%±0.19%、0.87%±0.31%（P=0.7298）；三组磷酸化Akt蛋白的相对表达量分别为1.00、2.17±0.06、1.69±0.07（P<0.01）；整合素信号通路中的磷酸化Fak的相对表达量分别为1.00、1.85±0.09、1.31±0.08（P<0.01）。此外，参与调节房水流出的基质金属蛋白酶1、2、3、7、9、10、11、12、14基因表达均升高（P均<0.01）；基质金属蛋白酶抑制剂1、2、3基因的表达均降低（P均<0.01）；白介素6基因相对表达量分别为1.00、1.28±0.06、1.47±0.06（P<0.01）。结论 高强度的机械牵拉能够增加小梁网细胞的活性，增强房水流出调节相关因子的表达，这可能是schlemm管成形术降低眼压的机制之一。     

恒河猴慢性高眼压模型视乳头和视神经纤维损伤模式

目的 观察恒河猴慢性高眼压模型与开角型青光眼患者的视乳头和视神经纤维损伤模式是否一致。方法 实验研究。采用眼科多波长激光仪光凝恒河猴（12眼）的小梁网以破坏小梁网功能使眼压升高,建立恒河猴慢性高眼压模型。术前和术后每周行眼压、眼底照相、视乳头参数和视神经纤维层厚度检测。结果 建模的12眼术前眼压为（16.08±2.02）mmHg,中央角膜厚度为（489.17±17.82）μm,眼轴为（20.32±0.84）mm。12只用于诱导建模的恒河猴眼,经3～4次激光光凝,11眼被成功诱导。27周平均眼压为（30.32±14.59）mmHg,眼压波动幅度为（8.19±7.45）mmHg。光学相关断层扫描成像显示整个盘沿面积从（1.67±0.44）mm2减小到（0.43±0.34）mm2。平均视神经纤维从（97.92±6.79）μm减少到（64.46±17.44）μm。结论 恒河猴慢性高眼压性模型模拟了人类高眼压/开角型青光眼发病机制和过程,在视杯对高眼压的反应、视杯可逆性缩小、视神经纤维损伤现象等方面一致,是开展高眼压性视乳头和视神经纤维层损伤研究理想的动物模型。     

青光安颗粒剂对自发性青光眼模型小鼠的降眼压作用及房水动力学的影响

背景 研究表明青光眼的眼压增高与转化生长因子-β(TGF-β)促进小梁网细胞外基质的堆积以及黏附分子CD44导致房水排出阻力增加有关.传统中药青光安颗粒剂是中医临床上常用的降眼压药物,其是否通过小梁网通路发挥作用尚不清楚.目的 研究青光安颗粒剂对自发性青光眼模型DBA/2J小鼠房水动力学的影响及其作用机制.方法 选取10只眼压正常的3月龄雌性DBA/2J小鼠作为对照组,采用计算机随机数字分配法将20只9月龄自发性眼压升高的DBA/2J小鼠随机分为高眼压组和青光安组,青光安组小鼠采用2.5 g/kg复方青光安颗粒剂灌胃,每天2次,连续15d,对照组和高眼压组小鼠以相同剂量生理盐水灌胃.采用经前房注入/抽吸系统进行眼压测量,分别以2.5、5.0 μl/min的速率继续灌注,计算房水流畅系数(C)值和房水流出阻力(R)值.将3月龄DBA/2J小鼠60只按计算机随机数字分配法分为高剂量青光安组、中剂量青光安组、低剂量青光安组和空白对照组,每组各15只,分别用25.00、12.50和6.25g/kg青光安颗粒剂灌胃,空白对照组用等容量生理盐水灌胃,给药后7d麻醉条件下提取各组小鼠含青光安药物血清和空白对照动物血清,然后收集各组小鼠含小梁网巩膜组织进行培养,采用纤连蛋白(FN)、层黏连蛋白(LN)和神经元特异性烯醇化酶(NSE)免疫组织化学染色鉴定小梁网细胞.终质量浓度为0、5、10、20、50和100 ng/ml的TGF-β处理小梁网细胞24h,采用MTT比色法检测各组细胞活性;用不同质量浓度含药血清培养经20 ng/mlTGF-β处理的小梁细胞,分别于培养后24、48和72 h采用ELISA法检测细胞上清液中TGF-β2受体质量浓度,采用Western blot法检测各组小梁网细胞中CD44蛋白的相对表达量.结果 对照组、高眼压组和青光安组小鼠在2.5 μl/min和5.0μl/min灌注速率下眼压明显不同,高眼压组小鼠眼压值明显高于青光安组和对照组,青光安组小鼠C值较高眼压组明显降低(1.08±0.36 vs.2.35±1.34),R值明显增加(1.05±0.47 vs.0.64±0.55),差异均有统计学意义(均P＜0.01).原代培养的细胞呈长梭形,FN、LN和NSE均呈阳性表达.5、10和20 ng/ml TGF-β处理组细胞活力值明显低于0 ng/ml TGF-β处理组细胞,差异均有统计学意义(均P＜0.05).与空白对照组比较,TGF-β组小梁网细胞上清液中TGF-β2受体质量浓度和细胞中CD44蛋白相对表达量均明显升高,差异均有统计学意义(均P＜0.01);细胞培养后24、48和72 h TGF-β+高剂量含药血清组细胞上清液中TGF-β2受体质量浓度和细胞中CD44相对表达量均明显低于TGF-β组和TGF-β+低剂量含药血清组,差异均有统计学意义(均P＜0.01).结论 青光安颗粒剂通过影响房水动力学因素达到降低青光眼眼压的作用.青光安含药血清能明显降低体外培养的鼠小梁网细胞中TGF-β2受体和CD44的表达.     

白细胞介素-1对房水动力学的影响

目的观察白细胞介素-1（IL-1）对房水动力学的影响，进一步验证其降低眼压的有效性及探讨其降低眼压的机制。方法SD大鼠15只，随机分成3组，A、B组随机一只眼前房注射重组鼠IL-1β30ng，另一只眼前房注射等体积的0．1％PBS作为对照，C组作为空白对照组。用药80h后，A组用药眼和对侧眼分别前房注射10μl^125I标记鼠清蛋白（^125I-RSA）和^131I标记的鼠清蛋白（^131I-RSA），B组相反，用药眼和对侧眼分别前房注射10μl^131I-RSA和125I-RSA，C组随机一只眼前房注射10μl^125I-RSA，对侧眼注射10μl^131 I-RSA，并于注药后每10min取静脉血一次，共7次，进行血循环中^125I-RSA或^131I-RSA放射性强度的测定，计算血样品中^125I-RSA／^131I-RSA的蛋白量比值。结果三组间比值差异有统计学意义（P=0．000），A组较C组增加27．20％，B组较C组降低25．44％。结论IL-1具有增加小梁网通道房水流出的作用，为其降低眼压提供客观依据。     

湿性年龄相关性黄斑变性患者注射雷珠单抗后早期眼压的变化

目的 观察湿性年龄相关性黄斑变性(wet age-related macular degenaration,wAMD）患者玻璃体腔注射雷珠单抗后早期眼压的变化。设计 前瞻性病例系列。研究对象 在北京医院接受玻璃体腔雷珠单抗（0.5mg/0.05ml）注射的wAMD患者135例（135眼）。方法 患者接受玻璃体腔注射雷珠单抗术前、术后10、30 min、2 h及术后1天,使用Topcon非接触眼压计分别测量眼压。观察患者注射后早期的眼压变化情况。主要指标 眼压。结果 患者术前眼压平均为（15.41±2.69） mmHg,术后10、30 min、2 h及术后1天的眼压平均值分别为（21.07±5.83） mmHg、（18.24±4.17） mmHg、（17.57±4.60） mmHg、（15.20±3.05） mmHg。术后2小时内的眼压与术前比有显著性差异（P均<0.05）,而术后1天眼压与术前比无显著性差异（P=0.239）。术后各时间段眼压升高比率呈逐渐下降趋势,其中术后10 min,眼压升高比率（眼压升高比率≥10 mmHg占17.78%;≥15 mmHg占5.19%）及升高绝对值（眼压≥21 mmHg占45.93%;≥25 mmHg占21.48 %;≥30 mmHg占8.15%）均明显高于其他时间段。术前眼压越高,术后10 min眼压≥21 mmHg的比例越高（P=0.000, OR=0.117, 95%CI=0.051-0.268）。结论 大部分湿性年龄相关性黄斑变性患者玻璃体腔注射雷珠单抗后早期眼压显著升高,2小时内眼压变化明显;术前眼压偏高可能是玻璃体腔注射雷珠单抗早期眼压升高的危险因素。     

内路小梁切开联合白内障超声乳化吸除术治疗原发性开角型青光眼的短期疗效

目的 对比内路小梁切开联合白内障超声乳化吸除术和单纯内路小梁切开术治疗合并白内障的原发性开角型青光眼（primary open angle glaucoma，POAG）的早期手术效果和并发症。设计 病例对照研究。研究对象2018年3月至2019年3月在北京同仁眼科中心住院手术治疗的合并白内障的POAG患者36例（36眼）。方法 根据患者选择的手术方式，将患者分为两组：行内路小梁切开联合白内障超声乳化吸除术的POAG患者12例（12眼）为观察组，行内路小梁切开术的POAG患者24例（24眼）为对照组。记录并比较两组患眼术前、术后1、2、3、5天、1周、1个月时眼压、视力、并发症和使用降眼压药的种类。主要指标 眼压、视力、并发症和降眼压药物种类。结果 观察组和对照组术前最高眼压分别为（34.08±8.21）mmHg和（37.75±8.61）mmHg（P=0.46）,观察组术后第1天、1周、1个月的平均眼压分别为（20.75±11.89）mmHg、（21.23±8.72）mmHg、（15.00±2.22） mmHg，对照组术前、术后第1天、1周、1个月的平均眼压分别为（16.08±5.63）mm Hg、（22.08±11.48）mmHg、（16.05±5.25）mmHg，两组术后眼压整体变化趋势随时间降低（P<0.001）,两组间术后眼压波动虽然存在差异，但是无统计学意义（P=0.77）。观察组和对照组术后1个月降眼压幅度分别为53.09%±15.19%和55.68%±15.63%（P=0.64）。观察组和对照组术前降眼压药物使用种类分别为（2.67±0.99） 种和（3.08±0.72）种（P=0.16），术后1个月时分别下降至（0.17±0.58）种和（0.96±1.33）种（P=0.06）。观察组和对照组组术后眼压反跳发生率分别为16.67%和54.17%（P=0.03）。前房积血为术后最常见的并发症, 观察组发生率为83.3%，对照组为62.5%（P=0.21)。观察组和对照组睫状体脱离发生率分别为25.0%和75.0%（P=0.004）。观察组中，8眼（66.7%）术后生活视力提高，4眼（33.3%）视力恢复至术前水平，0眼视力降低；对照组中，20眼（83.3%）术后生活视力恢复至术前水平，4眼（16.7%）视力降低（P<0.001）。结论 对于合并白内障的开角型青光眼患者，内路小梁切开联合白内障超声乳化吸除术和单纯内路小梁切开术在术后1个月时降眼压作用相似。联合手术术后视力改善明显，眼压反跳发生率较单纯内路小梁切开术低，是一种安全有效的手术方式，远期效果有待进一步观察。     

人眼房水流通中Schlemm管的作用

房水以非常低的流速(2.0μl/min)经过房水通道。但是,这种低流量却能在一个很短的距离(<1mm)内产生很大的压力下降(pressuredrop)。正常眼压力下降约6mmHg左右。但是,青光眼压力下降可达40mmHg之多。为了更好地理解房水流出通道以及它与眼内压升高及青光眼的关系,作者研究了Sehlemm管在正常眼压力下降中的作用。许多研究着眼于证实房水通道中的流出阻力的主要部位。灌注试验表明随着眼压逐渐升高、房水流出阻力呈近于直线性变化。可能产生阻力的部位为:(1)角巩膜小梁网部;(2)邻管网部;(3)Schlemm管内壁的内皮细胞;(4)Schlemm管本身;(5)集合管和房水静脉。由于     

巩膜池成形小梁切除术（与Cairns小梁切除术远期疗效对比）

据随机抽样原则，对巩膜池成形小梁切除术与Ｃａｉｒｎｓ小梁切除术各３２眼的远期疗效进行了对比。结果显示：Ｃａｉｒｎｓ小梁切除术后平均随访５４．３月，平均眼压２．６４ｋＰａ（２０．３ｍｍＨｇ），平均房水流畅系数０．２１２Ｃｕｍｍ／ｍｉｎ／ｍｍＨｇ；巩膜池成形小梁切除组术后平均随访５３．８月，平均眼压２．０２ｋＰａ（１５．５ｍｍＨｇ），平均房水流畅系数０．２８０Ｃｕｍｍ／ｍｉｎ／ｍｍＨｇ。两组数据经统计学处理，Ｐ＜０．０１，证实巩膜池成形小梁切除术的降压效果及房水滤过作用均优于Ｃａｉｒｎｓ小梁切除术，是一种较理想的抗青光眼手术方式。     

有无急性发作史的慢性闭角型青光眼患者小梁切除术18个月效果比较

目的 比较有无急性发作史的慢性闭角型青光眼（chronic angle closure glaucoma, CACG）患者行小梁切除术后18个月的效果。 设计 前瞻性比较性病例系列。 研究对象  4个临床中心参与的48例（48眼）具有急性发作史的原发性CACG患者（急性发作组）和101例（101眼）无急性发作史的原发性CACG患者（无急性发作组）。方法  所有患者经全面的眼科检查后行小梁切除术,术后随访18个月。记录手术前、手术后1、3天、1、2周、1、3、6、12、18个月的视力、眼压、用药情况及并发症。末次随访时无需使用降眼压药物的情况下眼压小于21 mmHg者认为手术成功。主要指标 眼压、视力变化（末次随访视力-基线视力）、眼压波动（随访中眼压的标准差）和手术成功率。 结果 手术前后视力的变化在急性发作组和无急性发作组分别为-0.06±0.47和0.02±0.36（P=0.166）。随访平均眼压分别为（14.9±4.0） mmHg和（14.6±2.8） mmHg（P=0.601）。随访中的眼压波动分别为（3.1±2.5）mmHg和（2.8±1.6）mmHg（P=0.452）。随访18个月时急性发作组和无急性发作组的眼压分别为（16.8±7.5） mmHg和（15.4±4.0） mmHg（P=0.259）。术后随访18个月急性发作组的手术成功率（85.7%）与无急性发作组的手术成功率（93.1%）的差异无统计学意义（?字2=2.11,P=0.146）。 结论  小梁切除术在有急性发作史和无急性发作史的CACG患者中18个月的手术成功率无明显差异。     

Aqueous humor dynamics in inbred rhesus monkeys with naturally occurring ocular hypertension

This study evaluates aqueous humor dynamics in rhesus monkeys from the University of Florida inbred colony with ocular normotension and naturally occurring ocular hypertension. Eight monkeys with untreated intraocular pressures (IOPs) of less than 18 mmHg in one eye (ONT group) and seven with untreated IOPs of greater than or equal to 18 mmHg in one eye (OHT group) were included in the study. Assessments included central cornea thickness by ultrasound pachymetry, IOP by tonometry, aqueous flow and outflow facility by fluorophotometry, and uveoscleral outflow by mathematical calculation. Animals were sedated with ketamine for all measurements. Values from the two eyes of each animal were averaged, with the exception of one animal that had only one good eye. Comparisons between groups were made by Student’s two-tailed unpaired t-tests. Compared to the ONT group, the OHT group had higher IOPs at all times measured (4:00 PM the day before the study, 21.2 ± 6.5 versus 14.4 ± 1.5 mmHg, p = 0.01; 9:00 AM the day of the study, 20.7 ± 6.6 versus 14.8 ± 1.2 mmHg, p = 0.03; 11:00 AM the day of the study, 16.0 ± 1.6 versus 13.3 ± 2.9 mmHg, p = 0.05) and lower aqueous flow (2.12 ± 0.40 versus 4.54 ± 1.11 μl/min, p = 0.0001), outflow facility (0.17 ± 0.10 versus 0.33 ± 0.07 μl/min/mmHg, p = 0.01) and uveoscleral outflow (p < 0.05). The elevated IOP in inbred Florida rhesus monkeys is a result of significantly reduced outflow facility and uveoscleral outflow. These animals also have slower aqueous flow than the ONT animals which does not contribute to the higher IOP.     

Comparative studies between species that do and do not exhibit the washout effect

Ocular perfusion studies from all non-human species performed to date consistently demonstrate a perfusion-volume-dependent increase in aqueous outflow facility known as the "washout" effect. However, this "washout" effect does not occur in human eyes. We have recently documented that, in bovine eyes, the washout associated increase in facility correlates with the extent of physical separation between the juxtacanalicular connective tissue (JCT) and the inner wall endothelium lining the aqueous plexus (the bovine equivalent of Schlemm's canal). We hypothesize that if washout truly correlates with inner wall/JCT separation then this separation should not occur in human eyes that do not exhibit the washout effect, even after prolonged perfusion. Eight enucleated human and eight bovine eyes were used in this study. Aqueous humor outflow facility was measured at 15 mmHg for long-duration (3 h) or short-duration (30 min to 1 h) perfusion (n=4 for each group). All eyes were perfusion-fixed at 15 mmHg, and examined morphologically with both light and electron microscopy. In bovine eyes, outflow facility increased 81% (p=0.049) from 1.06 +/- 0.06 microl/min per mmHg (mean+/-SEM) at baseline to 1.92 +/- 0.30 microl/min per mmHg after 3 h due to washout. The pre-fixation outflow facility in long-duration eyes (1.92 +/- 0.30 microl/min per mmHg) was 2-fold greater than pre-fixation facility in short-duration eyes (0.92 +/- 0.11 microl/min per mmHg; p=0.0387). In human eyes, washout was not observed; baseline outflow facility was similar between both groups (0.18 +/- 0.02 vs. 0.25 +/- 0.08 microl/min per mmHg; p=0.518); however, pre-fixation outflow facility in long-duration eyes showed a 40% decrease compared to baseline outflow facility in those same eyes (p=0.017, paired Student's t-test). In bovine eyes, significant expansion and rarefaction of the JCT and inner wall/JCT separation was much more prevalent in long-duration eyes, and data from all bovine eyes revealed a correlation between the extent of inner wall/JCT separation and the absolute value of outflow facility measured immediately prior to fixation (p=0.0024) as well as the washout-induced increase in outflow facility (p=0.0006). In human eyes, no significant morphologic differences were observed between long- and short-duration perfusion, with no observed change in inner wall/JCT separation or expansion between the two groups. Morphologic analysis revealed that the previously described "cribriform plexus" of elastic-like fibers was far more extensive in the JCT of human eyes, appearing to form numerous connections to the inner wall endothelium. The cribriform plexus appears to function as a mechanical tether that maintains inner wall/JCT connectivity in human eyes by opposing hydrodynamic forces generated during perfusion, potentially explaining the lack of washout in humans.     

Determination of the pseudofacility by fluorophotometry in the human eye

Purpose: Pseudofacility (decrease in aqueous humor flow in response to increase in the intraocular pressure (IOP)) has been evaluated in animals and in humans by a combination of different techniques that seriously alter the ocular physiology, such as the cannulation of the eyeballs, use of radioactive isotopes, perilimbic suction cups or tonography. Very different results have been obtained. Our objective is to relate the value of the aqueous humor flow in humans (as measured by fluorometry) with IOP. In order to obtain the widest range of IOP possible, we have performed this study in both normal as well as glaucoma patients. Methods: 48 eyes were studied, corresponding to 31 subjects (mean age 58 ± 14 years). Of these, 21 corresponded to normal subjects and 27 to glaucoma patients. The aqueous humor flow (F) was determined by fluorophotometry (Protocol of Yablonsky) and the IOP was measured thereafter. Results: The mean value of F was 2.1 ± 0.5 l/min for healthy eyes and 2.2 ± 0.7 l/min for glaucoma-affected eyes. The values were not different (p > 0.1). The mean value of the IOP was 15.3 ±3.1 mmHg in the normal population and 22.1 ± 4.3 mmHg in the glaucoma patients. A linear relationship between F and IOP was found (r = – 0.41, p < 0.05, decrease in F = 0.081 l min^–1 mmHg^–1). Conclusions: The value of the pseudofacility in the humans can be estimated at 0.081 l min^–1 mmHg^–1, which constitutes 27% of the total outflow facility. This figure also makes it possible to estimate the role of the ultrafiltration in blood in the production of the aqueous humor since it is assumed that active secretion is pressure-independent. The results obtained are concordant with a secondary but no unimportant role of the plasmatic ultrafiltration with respect to the active secretion.     

The effect of colchicine on the rate of formation of aqueous humour and the gross outflow facility in the albino rabbit

Colchicine, a naturally occurring plant alkaloid which prevents the polymerisation of cytoplasmic microtubules, lowers the intraocular pressure after topical administration or intravitreal injection. In this study wer have examined the effect of topically administered colchicine on the rate of formation of aqueous humour and the gross outflow facility in the albino rabbit eye. The disappearance of [¹⁴C]inulin from the anterior chamber was measured to calculate the rate of aqueous humour formation and in a separate group of animals the gross outflow facility determined using a constant pressure perfusion technique.Topically administered colchicine (10, 20 and 40 μg/eye) inhibited the rate of aqueous humour formation dose-dependently. The mean rate of formation in control eyes was 3·68 ± 0·09 μl/min (n = 16) decreasing to 1·8 μl/min (n = 9) in eyes treated with 40 μg colchicine. Furthermore, the gross outflow facility of colchicine treated (10 μg/eye) eyes (0·49 ± 0·03 μl/min/mmHg) was significantly greater (P < 0·05) than that of contralateral control eyes (0·39 ± 0·03 μl/min/mmHg).The pharmacological evidence available indicates that colchicine is acting via mechanisms of microtubule disruption to produce an ocular hypotensive response, suggesting that microtubules may be involved in the formation of aqueous humour and possibly the maintainance of cell shape and form in the outflow vessels of the anterior chamber.     

白内障超声乳化术对房水流畅系数的影响

目的：应用眼压描记法观察白内障超声乳化术对房水流畅系数的影响。

方法：选取2018-01/10在我院接受白内障超声乳化联合人工晶状体植入术的年龄相关性白内障患者126例126眼,手术前后采用非接触眼压计测量眼压,采用Schiotz电子眼压计测量房水流畅系数。

结果：术后1d本组患者眼压(19.01±1.81mmHg)较术前(17.09±1.70mmHg)升高,但术后1wk,1、3mo眼压均较术前降低(P<0.05); 术后1wk,1、3mo房水流畅系数(0.20±0.01、0.22±0.02、0.22±0.02)均较术前(0.19±0.02)明显改善(P<0.05)。

结论：白内障超声乳化术会增加房水流畅系数,这可能与术后眼压降低有关。     

Identification and functional characterization of ClC-2 chloride channels in trabecular meshwork cells

In the eye, trabecular meshwork (TM) cell volume may be an important determinant of aqueous humor outflow. Among their functions, ClC-2 chloride channels are thought to be involved in regulation of cellular volume and intracellular [Cl(-)]. We characterized the properties and modulation of an inwardly rectifying chloride current activated in these cells. Patch-clamp recordings revealed inwardly rectifying chloride currents activated by membrane hyperpolarization in primary cultures of both bovine (BTM) and human (HTM) TM cells. Electrophysiological properties and anion permeability sequence (Cl(-)>Br(-)>I(-)>F(-)) were in agreement with previous data for ClC-2 in other cells. The currents were blocked by Cd(2+) and enhanced by extracellular acidification, 8Br-cAMP and cell swelling, while extracellular alkalinization decreased them. RT-PCR experiments using total RNA revealed the molecular expression of ClC-2 channels. Previously we reported the involvement of swelling-activated chloride channels (Cl(swell)) and Ca(2+)-activated K(+) channels (BK(Ca)) in cell volume and outflow facility regulation. However, in the present analysis, cell volume experiments in calcein-loaded cells and outflow facility studies performed in bovine anterior segments revealed that ClC-2 channels do not make a significant contribution to the recovery of cellular volume or to the regulation of the outflow facility. Nevertheless, ClC-2 modulation by different stimuli may contribute to intracellular [Cl(-)] regulation and other cellular functions yet to be determined in the TM.     

Morphological and hydrodynamic correlates in monkey eyes with laser induced glaucoma

This study investigated the relationship between decreased outflow facility (C) and changes in hydrodynamic aqueous humor outflow patterns and morphology in cynomolgus monkey eyes with unilateral chronically elevated intraocular pressure (IOP). Argon laser photocoagulation burns to the trabecular meshwork (TM) were made in one eye of each monkey (N = 3), leaving the contralateral eye as a normotensive control. IOPs were followed by pneumatonometry for 16-70 months. C was measured by fluorophotometry before sacrifice. To label the hydrodynamic patterns of outflow, the eyes were enucleated and perfused with fluorescent microspheres (0.5 μm; 0.002%) at the last pressure measured before death minus 7 mmHg. The eyes were perfusion-fixed at the same pressure. Confocal images were taken along the inner wall (IW) of the Schlemm's canal (SC). The total length (TL) and the filtration length (FL) of the IW decorated by tracers were measured in frontal sections. The average percent effective filtration length (PEFL = FL/TL) was calculated for each eye. Sections exhibiting SC were processed and examined under light and electron microscopy. The average IOP was significantly higher in laser-treated eyes (mean ± SD = 61.33 ± 4.16 mmHg) than controls (22.67 ± 4.16 mmHg, P = 0.002). The average C was 13-fold lower in laser-treated eyes (0.03 ± 0.02 μl/min/mmHg) than controls (0.39 ± 0.17 μl/min/mmHg, P = 0.057). By confocal microscopy, in control eyes, SC was open and a segmental distribution of microspheres was found in the TM with a greater concentration near the collector channel (CC) ostia. Much less tracer labeling was seen along SC in laser-treated eyes than control eyes. The average PEFL in controls (47.47 ± 10.79%) was 6-fold larger than in laser-treated eyes (8.40 ± 4.81%, P = 0.048). The average distance between the inner and outer wall of SC was 5-fold greater in control eyes (18.99 ± 6.03 μm) than in laser-treated eyes (3.47 ± 0.33 μm, P = 0.048). By light microscopy, there was extensive pigmentation throughout the TM, denser extracellular matrix in the JCT region, and most of SC collapsed with focal herniations of the IW and JCT protruding into the CC ostia in laser-treated eyes. By electron microscopy, few or no microspheres were observed in laser-treated areas and the areas with SC collapse. More microspheres were observed near the CC ostia area in non-lasered areas. In conclusion, in the laser-induced glaucoma model, laser damage results in a reduction in the available area for outflow across the IW of SC which contributes to the decrease in C and thus elevation of the IOP. Constriction of SC, caused by the chronic elevation of IOP, further decreases the available area for outflow across the IW which decreases C even more in a vicious cycle. This study suggests that the available area for aqueous humor outflow across the IW of SC may play a role in regulating outflow resistance and maintaining IOP.     

Correlation Between Individual Differences in Intraocular Pressure Reduction and Outflow Facility Due to Latanoprost in Normal-Tension Glaucoma Patients

Purpose The amount of intraocular pressure (IOP) reduction achieved by the use of latanoprost eyedrops varies among patients, and there are even nonresponders. This report examines whether there is any correlation between the amount of individual variability in IOP reduction and the uveoscleral outflow facility after latanoprost eyedrop instillation in normal-tension glaucoma patients. Methods Sixteen normal-tension glaucoma patients (mean age, 56.4 years) were enrolled in the study to investigate the relationship between the amount of IOP reduction and outflow facility. Before treatment, subjects underwent circadian IOP measurement and then tonography, and the outflow facility was calculated. Subsequently, patients began treatment once daily with latanoprost instillation in one eye. After 4 weeks of daily latanoprost treatment, circadian IOP was measured again. Results Mean pretreatment outflow facility was 0.23 ± 0.05 μl/min per mmHg. On average, latanoprost instillation decreased IOP by 2.8 mmHg, but the reduction varied among individuals from −0.3 mmHg to 5.8 mmHg. No significant correlation was noted between the outflow facility and the IOP decline associated with latanoprost. Conclusion Because there was no significant correlation between individual IOP reduction by latanoprost and outflow facility, the differences in substantial change in uveoscleral outflow after latanoprost administration may be one explanation for the individual variation in IOP reduction after treatment with this drug. Jpn J Ophthalmol 2006;50:20–24 ? Japanese Ophthalmological Society 2006