CYP1B1基因敲除小鼠视网膜神经节细胞和视乳头结构的观察

目的 探讨CYP1B1基因敲除小鼠是否存在视网膜神经节细胞（RGCs）和视乳头结构的改变，以及这些改变与前房角发育之间是否存在关系。方法采用18只成年CYP1B1基因敲除小鼠作为实验对象，随机分成3组，每组6只。分别对视网膜、视乳头及前房角进行光学显微镜和透射电子显微镜观察，并用末端脱氧核苷酸转移酶介导的三磷酸脱氧尿苷缺口末端标记（TUNEL）法检测凋亡的视网膜神经细胞。以同龄C57BL／6J小鼠作对照研究。结果正常对照小鼠未发现视网膜、视乳头及前房角的异常改变。CYP1B1基因敲除小鼠中，光镜组观察发现2只眼视乳头形态结构的改变；电镜组观察发现2只眼RGCs呈现进行性的细胞浆和细胞核的浓缩；TUNEL染色组显示3只眼RGCs层和内核层出现TUNEL阳性细胞。上述7只眼均存在较严重的房角发育畸形。结论CYP1B1基因敲除小鼠部分存在RGCs的变性和视乳头结构的改变，这些改变与前房角发育畸形存在一定的相关性。     

掺钕─钇铝石榴石激光虹膜切开术后房角结构改变及眼压变化

对16只青紫蓝兔32只眼行掺钕-钇铝石榴石（Nd：YAG）激光虹膜切开术，借助光镜、电镜观察术后即刻至8个月房角结构的改变。同时，临床观察术前后眼压的变化。结果显示，Nd：YAG激光虹膜切开术后，房角被纤维蛋白渗出物、组织碎屑、色素颗粒及红细胞吞噬时间推移通过房水引流即小梁滤过及细胞吞噬消化得以逐渐清除。术后一过性眼压升高可能与房角小梁网机械性堵塞有关，而非激光能量直接损伤小梁网所致。     

人眼前房角发育的研究

对283例5周～足月的人胎眼前房角发育进行光镜、扫描电镜和透射电镜观察。房角形成是填充在房角区的中胚叶组织分化的结果,8周开始分化14～15周形成。覆盖房角及小梁的内皮细胞沿相邻细胞缘出现裂孔,随着时间的进展,裂孔不断增多变大。正常情况下,胚胎任何时期,房角区皆无一层膜样内皮细胞衬里。房角发育异常可因中胚叶分化不全;发育成疏松小梁网及Schlemm 氏管时失败;内皮细胞间没有形成裂孔。     

小梁网泵调控理论及其对青光眼诊疗的启示

小梁网房水引流功能异常导致眼压升高,是原发性开角型青光眼发生发展的最主要危险因素。房水具有搏动外流的特征,说明小梁网是弹性组织,其弹性状态与Schlemm管腔开放程度、管类瓣膜结构联动和深层巩膜静脉丛的开放与闭合密切相关,表明小梁网对房水的引流具有泵调控机制。本文对小梁网泵调控机制的理论基础、相关检查的临床应用及对青光眼微创手术的启示进行了系统介绍。希望小梁网泵调控理论为了解原发性开角型青光眼发病机制、选择治疗策略、优化和创新手术设计提供新的视角。(眼科,2022,31:405-412)     

哈萨克族牧民慢性闭角型青光眼前房角组织病理研究及临床意义

目的:观察研究新疆哈萨克族慢性闭角型青光眼患者前房角组织的病理改变及临床意义。方法:对手术切除的小梁和虹膜组织常规脱水石蜡包埋,作矢状连续切片,苏木素-伊红染色,光镜下观察。结果:镜下见小梁网眼变窄或消失,内皮细胞减少,小梁网中有色素沉积,部分小梁网完全被色素斑块遮盖,看不清小梁结构,部分可见小梁虹膜并置,小梁纤维化伴玻璃样变性。Schlemm腔内壁内皮细胞不同程度增生,致管腔呈不规则狭窄甚至管腔闭塞,部分管腔内可见色素沉积。虹膜变薄,基质疏松,有的虹膜间质血管壁增厚并呈玻璃样变,部分可见虹膜间质薄壁血管形成。结论:慢性闭角型青光眼前房角组织的病理损伤是一个渐进的过程,早期诊断,早期治疗,既可以有效地防止视功能的损害,又能有效地预防因高眼压而造成的前房角组织的损害。     

我国人眼正常前房角小梁网组织化学及超微结构的研究

本文对7例正常人眼前房角小梁网进行了组织化学——酸性粘多糖及超微结构的研究。结果表明人类正常眼前房角小梁中存在酸性粘多糖,以内皮网处较多,大部分可被透明质酸酶消化。小梁带中螺旋纤维可能是小梁网柔韧性的结构基础,小梁带基板层与小梁带内皮细胞胞浆存在密切联系,小梁内皮细胞间的连接,可能对防止小梁带受外界因素影响而发生位移有一定稳固作用,内皮网间质中存在Ⅰ、Ⅱ型斑状物及胶原成分,39岁以下眼中含量较少,老年眼中较多。Schlemm 氏管内壁内皮细胞胞浆中液泡是房水排出的细胞内途径,证实了本文作者1963年提出的论点。     

基于双光子共聚焦成像技术的小梁网通道原位成像研究

目的 观察基于双光子共聚焦成像技术在不进行组织固定和染色的情况下获取大鼠小梁网外流通道微观结构图像的应用效果。设计 实验研究。研究对象 SD大鼠6只。方法 将6只大鼠随机分成两组（A组和B组），A组大鼠的完整眼球用于小梁网通道纵截面成像数据的获取；B组大鼠左眼球剖开用于小梁网通道横截面及眼球矢状面成像，右眼球为对照组。采用自行搭建的双光子共聚焦成像系统（激发波长950 nm、侧向分辨率0.3 μm、轴向分辨率1.5 μm），从前房角处进行成像，获取不同方位小梁网及其周围组织的微观结构信息。通过图像处理方法，定量分析Schlemm管截面直径随成像深度的变化情况。主要指标 不同方位小梁网通道成像深度、小梁网微观结构特点及Schlemm管平均截面直径。结果 基于双光子共聚焦成像技术分别获取到小梁网通道纵截面、横截面以及眼球矢状面的图像数据。不同深度的小梁网通道组织形态结构各异，深层小梁网纤维排列致密，形成的孔隙较小；浅层小梁网的纤维相互交错，形成的孔隙较大，利于房水流出。在角巩膜缘下方190~215 μm成像深度范围内，Schlemm管的平均截面直径在34~68 μm之间变化。结论 双光子共聚焦成像可观察小梁网通道的微观结构，为进一步小梁网通道房水外流动力学研究奠定了基础。     

原发性急性闭角型青光眼小梁切除术前后眼前节超声生物显微镜测量比较

目的通过超声生物显微镜（UBM）眼前节测量了解急性闭角型青光眼行小梁切除术后眼前节组织空间结构变化。方法对20例（21只眼）急性闭角型青光眼患者,术前及术后3个月行UBM测量中央前房深度、房角开放距离、小梁网睫状突距离、虹膜厚度、虹膜晶状体接触距离。结果术前与术后比较,中央前房深度、小梁网睫状突距离、虹膜厚度无统计学差异（P〉0．05）,房角开放距离、虹膜晶状体接触距离差异有统计学意义（P〈0．05）。结论急性闭角型青光眼患者行小梁切除术后,房角开放距离增加,瞳孔阻滞缓解,但睫状突前位没有改变。UBM是一种客观的、有效的随访工具。     

水通道蛋白-1在小梁切除术之切除组织中的表达

目的观察青光跟患者小梁和虹膜组织与正常跟组织水通道蛋白-1（AQP-1）的表达差异。方法收集开角型和闭角型青光跟小梁切除术时切除的小梁和虹膜组织，免疫组织化学法检测AQP-1的表达，并与正常跟相应组织对照。结果正常眼小梁网组织、Schlemm’s管内皮细胞、周边虹膜组织中上皮和基质组织可见AQP-1呈强阳性着色，开角型青光眼和闭角型青光眼组织标本小梁网AQP-1阳性染色较正常弱；部分急性闭角型青光眼患者周边虹膜组织标本上皮层较基质组织染色明显弱。结论开角型青光眼小梁网AQP-1的表达减少可能与小梁网的发育有关，闭角型青光眼虹膜上皮和小梁网AQP-1的表达减少可能与虹膜萎缩或高眼压有关。     

DBA/2J小鼠房水引流通道中色素颗粒分布及其与眼压关系的实验研究

目的 探讨色素性青光眼动物模型DBA/2J小鼠房水引流通道中色素颗粒形态、大小、数量与眼压之间的关系。设计实验研究。研究对象9周龄雄性DBA/2J小鼠20只(40眼)。方法 定期监测眼压和眼前节变化,12、20、28、36周龄随机各取3只(6眼),按眼压正常与否分成正常眼压和高眼压组。光镜观察不同眼压组房水引流通道结构及其内色素颗粒的分布。透射电镜观察前房和小梁网内色素颗粒的形态,用Image软件随机测量100个色素颗粒的直径,并比较不同眼压组小梁网内色素颗粒直径的差异。主要指标眼压,前房和小梁网内色素颗粒的直径。结果 DBA/2J小鼠从20周龄起出现虹膜色素颗粒脱失、播散,虹膜基质萎缩伴透照缺损。12和20周龄小鼠均未出现高眼压,28和36周龄分别有36.4%和75%的小鼠眼压升高。不同周龄间眼压差异有统计学意义(χ²=37.82,P<0.001)。与正常眼压组相比,高眼压组虹膜厚度变薄,前房内和虹膜前、后表面富含色素颗粒的细胞堆积,前房角变窄,小梁网内大量色素颗粒沉积。DBA/2J小鼠前房内色素颗粒的形状为圆形,平均直径(0.44±0.12μm);或椭圆...     

Anterior and posterior parts of human trabecular meshwork

From gonioscopic observations, the trabecular meshwork was tentatively divided into anterior and posterior parts. The anterior part was defined as the zone from the Schwalbe's line to the anterior edge of the Schlemm's canal, and the posterior part was from the anterior edge of the Schlemm's canal to the angle recess. The patients' own blood cells were injected into the anterior chamber of two eyes about to be enucleated due to malignant tumors, and cell distribution in the trabecular meshwork was examined histologically. Blood cells in the posterior part of the trabecular meshwork were numerous, particularly in the area adjacent to the Schlemm's canal and anterior to the ciliary muscle at the angle recess, yet only a few cells were seen in the anterior part. At the angle recess, the blood cells accumulated in the perivascular connective tissue of the major arterial circle of the iris. These observations suggest that the posterior part of the trabecular meshwork is the most important for aqueous humor drainage in the human eye, both with regard to the conventional and unconventional routes, while the anterior part plays a lesser role in the aqueous outflow. It is also suggested that some proportion of the aqueous humor entering the tissues at the angle recess may flow through the perivascular tissue of the major arterial circle of the iris.     

The effects of a new type of laser on fixed tissue of the angle of the anterior chamber in the monkey eye (author's transl)]

Segments of fixed tissue of the chamber angle of the monkey eye are irradiated with a neodymium (YAG-) q-spoiled laser at a pulse duration of 50 ns, a pulse energy of 200 mJ and an optic distance of 15 mm. Perforating injuries are observed between the anterior chamber and Schlemm's canal. When an acute angle of the laser beam relative to the cornea is chosen, the application point must be at the anterior part of the trabecular meshwork, close to the cornea, to open the canal of Schlemm. An impact further back toward the iris would create cyclodialysis.     

Long-term effects of Q-switched ruby laser on monkey anterior chamber angle

In an attempt to clarify whether pulsed lasers might be able to cause permanent fistulas from the anterior chamber to the interior of the canal of Schlemm, slightly suprathreshold, low energy, small diameter Q-switched ruby laser pulses were applied to the trabecular meshwork of nine eyes of six rhesus monkeys. Clinical examinations during the next 2 months disclosed no adverse effect on the cornea, iris, lens, or retina. There was transient mild inflammation in five eyes. Intraocular pressure was not changed significantly; the facility determined by perfusion of the anterior chambers at 2 months was normal. Light microscopy and scanning electron microscopy show localized trabecular lesions; some are slightly indented, but there is no persistent penetration to Schlemm's canal. Endothelial cells, confluent with those of the cornea, cover the inner (anterior chamber) surface of the lesions. Cross-sections through the center of a lesion show that trabecular meshwork and Schlemm's canal have been obliterated by the treatment and healing; these changes are similar to those previously seen after argon laser monkey trabecular treatment. In the untreated areas, between pulsed laser application sites, trabecular meshwork and Schlemm's canal are normal by light microscopic and scanning electron microscopic examination. Any effect on IOP from this particular type of pulsed laser treatment of the trabecular meshwork is probably not due to trabeculopuncture and flow of fluid through the fistula.     

Ablation of the trabecular meshwork

In an experimental investigation we examined the possibility to create an open pathway between the anterior chamber and Schlemm's canal by excimer laser ablation of the trabecualr meshwork (AT) in enucleated eyes. A quartzfiber was directed through the anterior chamber to the opposite chamber angle. With an energy of 0.3-1.5 mJ and wavelengths of 248 and 308 nm pores were easily made into the trabecular meshwork leading to a direct connection between the anterior chamber and Schlemm's canal. This result was confirmed by histologic examination of the globes. The trabecular meshwork has disappeared completely. The surrounding tissue reveals only minimal thermal effects due to the laser burns. With the same method cyclodialysis and basal iridectomy may be performed. The operation is simple and effects can be placed with great accuracy.     

Light and electron microscopy of the anterior chamber angle structures following surgical disinsertion of the ciliary muscle in the cynomolgus monkey.

Light and electron microscopic studies were done on 11 cynomolgus monkey eyes which had undergone total iris removal followed by surgical disinsertion of the ciliary muscle from the scleral spur 4.7 to 14.4 months earlier. Anterior chamber perfusion to measure gross outflow facility had been performed one to nine times postoperatively. Over most of the circumference in most eyes (1) the ciliary muscle had been retrodisplaced from the scleral spur and had reattached to the sclera more posteriorly; (2) ciliary muscle, trabecular meshwork, and Schlemm's canal appeared normal. A cyclodialysis cleft was never seen. Fixation of some eyes in the in vivo and in vitro presence of pilocarpine demonstrated the contractibility of the retrodisplaced muscle. In isolated areas where the ciliary body had been surgically cut, scar tissue of varying thickness connected scleral spur, sclera, ciliary body, zonule, and lens capsule, but did not infiltrate trabecular meshwork or Schlemm's canal. In such sectors, plasma cell-like cells replaced trabecular endothelial cells and were also present in the scar tissue, ciliary muscle, and surrounding vessel walls in the scar and sclera. In sectors of two eyes, a previously existing trabecular operculum extended posteriorly and completely covered the meshwork. The meshwork in these sectors was poorly perfused by aqueous humor, and electron-dense deposits were present beneath the inner wall of Schlemm's canal. Four totally iridectomized and two unoperated eyes from these monkeys were also examined; ciliary muscle, trabecular meshwork, and Schlemm's canal appeared normal in all, despite the numerous anterior chamber perfusions.     

A case of Rubinstein-Taybi syndrome suspected with goniodysgenetic glaucoma

We reported a case of Rubinstein-Taybi syndrome suspected in association with goniodysgenetic glaucoma, and studied using light and electron microscopy the anterior chamber angle tissues obtained surgically by trabeculectomy. The patient was 31-year old male, who had a systemic appearance of Rubinstein-Taybi syndrome with dwarfism, mental retardation, antimongoloid slant, flat-broad based thumbs, low set ears, high arched plate except for whorl of dermatographism. In addition to these malformations, goniodysgenetic glaucoma was also present which is characterized by underdevelopment of the angle recess and invisible ciliary body band in gonioscopic examination. The histopathological studies of the specimens revealed the presence of a compact tissue filled with a large amount of collagen fibers with few cells in the juxta-canalicular tissue of Schlemm's canal. There were 3 to 4 layers of trabecular sheets of corneoscleral meshwork at the anterior chamber side of the compact tissue. We conclude that the presence of the compact tissue under Schlemm's canal represents goniodysgenesis, underdevelopment of the trabecular meshwork, which is the primary cause of the glaucoma in this case.     

Ab interno trabeculectomy: development of a novel device (Trabectome) and surgery for open-angle glaucoma

PURPOSE: To design an instrument to selectively remove trabecular meshwork and Schlemm's canal inner wall (SCIW), and demonstrate its effectiveness by histologic analysis of treated cadaveric human tissue. METHODS: The design parameters of the instrument were the ability to permanently remove a segment of trabecular meshwork and Schlemm's canal inner wall without causing damage to surrounding tissue, and to allow use with standard anterior segment surgical techniques and equipment via an ab interno approach. Treatment was applied to 20 segments of human corneoscleral rims. The treated areas were examined using a confocal microscope and compared with matching areas in untreated controls and simulated goniotomy. RESULTS: The resultant instrument system surgically removes the trabecular meshwork and Schlemm's canal inner wall from an anterior chamber approach. It consists of a disposable surgical handpiece with irrigation, aspiration, and electrocautery to focally ablate the target tissues. The attached console includes a high-frequency (550 KHz) electrosurgical generator and irrigation/aspiration controlled by a foot pedal. Histologic examination of specimens treated with the Trabectome displayed disruption of the trabecular meshwork and Schlemm's canal inner wall without damage to surrounding structures. The specimens treated by simulated goniotomy displayed significant damage to the outer wall of Schlemm's canal and the surrounding sclera. The controls showed no disruption or damage to any tissues. CONCLUSIONS: The Trabectome system is designed for performing trabeculectomy via an ab interno approach. It successfully removed sections of trabecular meshwork and Schlemm's canal inner wall with less injury to the adjacent tissue compared with goniotomy knife in vitro. Theoretically, this procedure should provide direct access of aqueous humor to Schlemm's canal.     

Effect of repeated anterior chamber perfusion on intraocular pressure and total outflow facility in the cynomolgus monkey

Total outflow facility was determined by two-level constant pressure perfusion of the anterior chamber in surgically virgin, aniridic, and ciliary muscle disinserted cynomolgus monkey eyes 6 to 13 times at 1- to 2-month intervals over periods of 8 to 24 months. Facility decreased approximately 15 to 20% between consecutive thirds of the perfusion history, independent of eye type. The facility decreases were too large to be explained by decreased uveoscleral facility or pseudofacility, and were not mediated by the iris, ciliary muscle, or gonioscopically or ultrastructurally apparent chamber angle alterations. They most probably reflected functional alterations in the trabecular meshwork/inner wall of Schlemm's canal. Intraocular pressure as measured by applanation tonometry did not increase progressively, most probably due to a decreased rate of aqueous humor formation.