可疑原发性房角关闭患者激光周边虹膜切除术后一年的房角生物测量分析

目的应用超声生物显微镜(UBM)测量评价可疑原发性房角关闭(PACS)患者激光周边虹膜切除术(LPI)后的房角生物学形态变化。设计前瞻性病例系列。研究对象河北省邯郸市眼科医院连续的55例PACS患者。方法每例患者随机选取一眼行LPI治疗。LPI术前及术后12个月进行眼科常规检查及UBM检查。主要指标UBM图像房角参数。结果 LPI术后12个月时AOD500、AOD750、TCPD500、TCPD750、TIA500、TIA750、ARA500及ARA750较术前均明显增加(P均<0.001)。AOD750、TIA750及ARA750术后12个月时较术前增加幅度均在1倍以上(1.08～1.14倍)。LPI术后,激光眼上方房角的变化幅度最大,颞侧的变化幅度最小,且巩膜突750μm前的参数的增幅均较巩膜突500μm的参数增幅大。与对侧眼相比,除IT750与IT500以外,术后12个月各项参数的测量值均明显增加,差异具有显著性(P均<0.01)。且巩膜突750μm前的参数增幅均较巩膜突500μm增幅大。结论一年的随访研究显示,LPI能显著增宽PACS者周边前房角。巩膜突750μm前的参数在评价周边前房角上更为敏感。     

应用相干光断层扫描与超声生物显微镜检测汉、维两族原发性闭角型青光眼的比较

目的应用前节相干光断层扫描（OCT）和超声生物显微镜（UBM）评价汉族、维吾尔族原发性闭角型青光眼（PACG）患者及正常前房相关参数的差别。方法 64例正常受试者（汉族、维吾尔族各32例,各32只例）和64例慢性PACG的受试者（汉族、维吾尔族各32例,各32只眼）加入本研究。所有受试者都接受了前房角镜、OCT、UBM检查。应用专门的图像处理软件对OCT和UBM图像中的各项前房相关的定量参数进行了测量,分析比较两个民族两种检查的眼前节参数,及其与房角镜检查结果进行相关性分析。结果各组单项参数在前节OCT、UBM检查的平均值非常接近,差异无统计学意义（P〉0.05）。汉族和维族慢性闭角型青光眼患者的各项参数检查结果在前节OCT、UBM检查差异无统计学意义（P〉0.05）,汉族和维族正常者的各项参数检查结果在前节OCT、UBM检查差异无统计学意义（P=0.231）,但在慢性PACG患者,房角角度（ACA）、虹膜厚度（IT）小于汉族患者,维吾尔族患者房角开放距离（AOD500）、房角隐窝面积（ARA500、ARA750）、小梁虹膜间面积（TISA500、TISA750）5项参数均大于汉族患者,同一种族正常和慢性PACG患者间的各项参数检查结果在前节OCT或UBM的差异有统计学意义。ACA、ACD、LAAP、AOD500、ARA500、TISA500 6项前房定量参数在前节OCT、与UBM检查结果中均显示与房角镜检查结果有较好的相关性。结论无论前节OCT或UBM使用上述各项检测参数均可针对汉、维两族的患者进行PACG的检测,且各项参数的正常值可参考汉族人群数据。     

应用光学相关断层扫描与超声生物显微镜检测窄前房角的比较

目的：评价应用光学相干断层扫描（OCT）和超声生物显微镜（UBM）生成的定量图像对狭窄前房（AC）角的分类的准确性。 方案：观察比较研究法。 方法：应用1．3μm的光源建立了高速（每秒4000次轴向扫描）的眼前节OCT模型。17名正常受试者（17只眼）和7名患有窄角型青光眼的受试者（14只眼）加入了本研究。所有受试者都接受了前房角镜检查、OCT和UBM。应用专门的处理软件对OCT和UBM图像中的各项AC角度的定量参数[房角开放距离、房角隐窝面积和小梁虹膜间面积（我们定义的一个新参数）]进行了测量。 主要结果判定：用图像衍生的AC角度参数鉴别窄房角的特异性和敏感性。 结果：31只眼中的8只眼被归类为窄房角（在所有象限中Shaffer分级≤1）。OCT和UBM测定的AC角度参数有着相似的平均值、重复性和敏感特异性曲线（sensitivity-specificity profiles）。这些参数的接受机操作特征曲线下的面积都在0．96到0．98的范围内。 结论：应用光学相干断层扫描在定量测定AC角度和检测窄房角方面与UBM效果相似。另外，它还有应用简便和无需接触眼球的特点。光学相干断层扫描是一种对有发生窄角型青光眼风险个体进行筛查的很有前景的方法。     

原发性先天性青光眼眼前段活体结构观察

目的:观察先天性青光眼的超声生物显微镜(UBM)图像特征并探讨先天性青光眼的发病机制。方法:采用高频、高分辨率的超声生物显微镜对6例先天性青光眼患者10只眼的房角、虹膜、睫状体等进行扫描和分析,并与7例正常人或无相关疾病患者的7只眼进行比较。结果:超声生物显微镜检查显示出原发性先天性青光眼的房角、虹膜、睫状体及巩膜突发育不良,虹膜基质薄,睫状体细小,巩膜突解剖特征不明显。原发性先天性青光眼组的虹膜厚度及睫状体大小的测量和统计学比较均明显小于正常对照组。结论:超声生物显微镜可以观察到常规眼科检查观察不到的部位,如睫状体、房角隐窝、虹膜后表面等等。原发性先天性青光眼具有虹膜基质薄、睫状体细小、巩膜突解剖特征不明显等特征,提示原发性先天性青光眼除了房角发育异常外,尚合并存在虹膜、睫状体巩膜突发育不良。其中虹膜、睫状体发育不良可能是先天性青光眼相对比较重要的发病机制。眼科学报1998;14:83—86。     

原发性前房角关闭眼激光周边虹膜切开术后前房角形态学变化

目的 定量检测和评价原发性前房角关闭(PAC)眼行激光周边虹膜切开(LPI)术后前房角形态学变化.方法 临床病例系列研究.对入选的31例(54只眼)PAC患者于LPI术前、术后2周、6及12个月,进行眼科常规检查,定量检测超声活体显微镜(UBM)图像中前房角的各项参数.各随访时间点的UBM参数比较采用重复测量的方差分析,巩膜突前750μm与500 μm处各参数的比较采用配对t检验.结果 LPI术后前房深度较术前加深0.10 mm,但差异并无统计学意义(F=3.50,P＞0.05).LPI术前,巩膜突前750 μm处,前房角开放距离(66.2±51.6) μm,小梁网与虹膜间夹角5.0°±3.5°,前房角隐窝面积(0.025±0.017)mm2,小梁网与睫状突距离(571.0±97.2) μm;LPI术后2周、6及12个月,巩膜突前750 μm处,前房角开放距离分别为(165.0±70.3)、(185.8±68.5)及(196.1±77.7)μm,小梁网与虹膜间夹角分别为(11.9±4.9)、(13.3±4.8)及14.0°±5.4°,前房角隐窝面积分别为(0.058±0.024)、(0.065±0.023)及(0.068±0.026)mm2,小梁网与睫状突间距离分别为(647.1±113.0)、(701.8±93.4)及(670.1±95.4) μm,均较LPI术前增加,差异均有统计学意义(前房角开放距离:F =92.60,小梁网与虹膜间夹角:F=92.60,前房角隐窝面积:F=92.60,小梁网与睫状突间距离:F =34.00;P ＜0.05).术后前房角开放距离、小梁网与虹膜间夹角及前房角隐窝面积均较术前增加1倍以上.巩膜突前750 μm处检测参数的增加幅度均较巩膜突前500 μm处大(前房角开放距离:t=5.90,P＜0.05;小梁网与虹膜间夹角:t=2.70,P＜0.05;前房角隐窝面积:t=2.00;P =0.05).结论 LPI能显著增宽PAC眼的周边前房角,且随访观察1年期间前房角仍开放.巩膜突前750 μm处的参数比500μm处参数对评价周边前房角形态变化更为敏感.     

激光周边虹膜切开术后的前房角变化

目的利用前节相干光断层扫描（OCT）对激光周边虹膜切开术（LPI）手术前后的前房角变化进行研究。方法 32例（34只眼）接受LPI治疗后分别在手术前及手术后1周检查前节OCT,测量房角开放距离（AOD）、小梁虹膜空间面积（TISA）、巩膜突与虹膜的夹角,部分眼睛同时检查了超声生物显微镜（UBM）。结果 OCT检查可以发现LPI术后的房角变宽,AOD、TISA、巩膜突与虹膜的夹角变大,但是UBM检查为非瞳孔阻滞型的OCT参数变化不明显。结论前节OCT有助于判断LPI手术的疗效。     

房角关闭机制指导下可疑原发性房角关闭患者激光干预的疗效评价

目的 根据房角关闭的不同机制,对可疑原发性房角关闭（PACS）患者行激光周边虹膜切除（LPI）术或LPI联合激光周边虹膜成形（LPIP）术,通过超声生物显微镜（UBM）评估PACS患者激光早期干预的疗效。设计 前瞻性病例系列。 研究对象2016年1月-11月在河北省邯郸市眼科医院连续就诊的PACS患者50例（65眼）。方法 根据房角关闭的不同机制,通过UBM评估患眼,对所有入选患眼均首先行LPI治疗,术后第3天复查UBM,检查提示仍存在至少一个象限房角呈接触性关闭的患者再进一步联合LPIP治疗。术后3天复查UBM,根据测量的相关参数的前后变化评价治疗效果。主要指标 UBM图像中的中央前房深度（ACD）,巩膜突前500 μm处的房角开放距离（AOD）、小梁虹膜夹角（TIA）、房角隐窝面积（ARA）、小梁睫状体距离（TCPD）、虹膜厚度（IT）。结果 65眼中,47眼（72.3%）行LPI治疗后3天UBM检查未发现存在至少一个象限的房角接触性关闭,术后AOD、TIA、TCPD、ARA较术前均明显增加（P均<0.01）,IT较术前无明显变化（P=0.465）;18眼（27.7%）行LPI术后3天,UBM提示存在至少一个象限的房角接触性关闭,联合LPIP治疗后AOD、TIA、TCPD、ARA较术前均明显增加（P均<0.01）,IT较LPI术后减少更明显（P<0.01）。结论 LPI后UBM可用于判断房角关闭的机制,并据此考虑是否联合LPIP,可进一步改善非单纯性瞳孔阻滞机制的可疑房角关闭患者的疗效。     

根据超声生物显微镜和眼前节OCT图像对房角关闭机制进行分型的一致性研究

背景 房角关闭是引起原发性房角关闭性疾病(PACD)的病理基础,了解不同类型的房角关闭机制对于PACD的危险因素评估、预防及诊治有重要意义.临床多采用超声生物显微镜(UBM)对房角关闭机制进行分型,但该检查为接触性,在使用中具有一定的局限性.眼前节OCT(AS-OCT)是一种非接触性的眼前节成像方法,能够对房角结构进行定性和定量评估. 目的 探讨根据UBM图像和AS-OCT图像对中国PACD患者房角关闭机制进行分型的一致性.方法 采用横断面研究.纳入2013年9-10月在北京同仁医院就诊并接受UBM和AS-OCT检查的PACD患者.UBM检查采集每眼上方、下方、鼻侧和颞侧4个方位的眼前节图像,AS-OCT检查采取四线扫描模式(包括0°～ 180°、45°～225°、90°～ 270°和135°～315°)对眼前节进行成像.根据UBM图像和AS-OCT图像分别进行房角关闭机制分型,并分为瞳孔阻滞型、睫状体前位型和周边虹膜肥厚型.每例受检眼的4张UBM图像及4张AS-OCT图像中分别至少2张显示相同的房角关闭机制分型作为该眼的UBM及AS-OCT分型.纳入符合标准的患眼,若双眼均符合标准则纳入右眼.用Kappa系数评估AS-OCT和UBM 2种方法对房角关闭机制分型结果的一致性.结果 最终纳入PACD患者40例40眼,其中右眼27眼,左眼13眼.根据UBM图像及房角关闭机制的分型标准,瞳孔阻滞型12眼,占30.0％;睫状体前位型23眼,占57.5％;周边虹膜肥厚型5眼,占12.5％.根据AS-OCT图像及房角关闭机制的分型标准,瞳孔阻滞型为12眼,占30.0％.睫状体前位型21眼,占52.5％;周边虹膜肥厚型7眼,占17.5％.两种房角关闭机制分型方法间的Kappa值为0.872,即高度一致. 结论 成功建立了根据AS-OCT图像对中国PACD患者房角关闭机制分型的标准,根据AS-OCT图像和UBM图像对房角关闭机制进行分型的判断结果高度一致.     

原发性闭角型青光眼的超声生物测量研究

目的 应用A型眼科超声和超声生物显微镜(ultrasound biomicroscope,UBM)研究原发性闭角型青光眼(primary angle-closure glaucoma,PACG)不同瞳孔直径下眼前节和后房结构的解剖特征.方法 正常对照组24例(48眼)及PACG组24例(48眼)按照检查时瞳孔直径(d)分为以下3组:d ＜2.5 mm组,2.5 mm≤d≤4.0 mm组,d＞4.0 mm组,进行眼轴测量和UBM检查.眼轴长度采用STORZ-A型眼科超声诊断仪测量,眼前节各项参数采用Zeiss-Humphrey-840型UBM检查.结果 PACG眼较正常眼前房浅,眼轴短,小梁网虹膜夹角变小,房角开放距离缩短,睫状突高度减小,巩膜外侧面与虹膜长轴的夹角、与睫状突夹角减小.PACG眼的角膜厚度较正常眼增厚,分别为(584.208±78.210) μm、(577.583±39.681)μm,但差异无统计学意义(P＞0.05).反映瞳孔阻滞的参数虹膜晶状体接触距离差异无统计学意义(P＞0.05).PACG眼与具有正常瞳孔直径的眼相比,瞳孔直径越大,小梁网虹膜夹角越小,根部虹膜越厚,虹膜晶状体接触距离越小,而正常眼的根部虹膜厚度、小梁网虹膜夹角、虹膜晶状体接触距离与瞳孔直径无相关性.结论 PACG眼与正常眼解剖结构在任何瞳孔直径下均不同.PACG眼随瞳孔直径增大,眼前节更为拥挤,睫状体旋前增加房角关闭可能.     

1310 nm傅里叶域眼前节OCT的成像特点及与其他两种OCT的对比分析

目的 探讨1310 nm傅里叶域实时眼前节光学相干断层扫描(OCT)的成像特点及与RTV-ue100 OCT,Visante OCT对眼前节重要结构的成像能力的对比.方法 横断面研究.选择受试者6例(12眼,24个方位),运用1310 nm傅里叶域实时眼前节OCT,RTV-ue100 OCT与Visante OCT进行房角成像,对巩膜突、Schlemm's管、房角隐窝及Schwalbe线进行定义,测量前房角角度(TIA500)、500 μm前房角开放距离(AOD500)、500 μm小梁虹膜面积(TISA500)、Schlemn's管长径以及面积.运用Fisher's确切概率法对比3台仪器对房角重要结构的定义能力,并采用独立样本t检验研究三者生物学测量结果的差异.结果 傅里叶域实时眼前节OCT可在8眼(67％)13方位(54％)、12眼(100％)22方位(92％)、12 眼(100％)24方位(100％)及6眼(50％)9方位(38％)分别定义巩膜突、Schlemm's管、房角隐窝及Schwalbe线.RTV-ue100 OCT可于8眼(67％)8方位(33％)定义Schlemm's管,10眼(83％)19方位(79％)定义Schwalbe线,不能定义巩膜突与房角隐窝.Visante OCT于12眼(100％)21方位(88％)定义巩膜突,12眼(100％)24方位(100％)定义房角隐窝,不能定义Schlemm's管与Schwalbe线.3种OCT对巩膜突、Schlemm's管、房角隐窝、Schwalbe线定义能力差异有统计学意义(F=24.30、25.20、28.22、17.10,P＜0.01).傅里叶域实时眼前节OCT与Visante OCT测量TIA500、AOD500、TISA500的差异无统计学意义.傅里叶域实时眼前节OCT与RTV-ue100 OCT测量Schlemm's管面积、长径差异无统计学意义.结论 三种OCT都实现了前房角的清晰成像,显示角膜、巩膜、结膜以及巩膜突、Schlemm's管与Schwalbe线等房角结构.RTV-ue OCT和傅里叶域实时眼前节OCT的图像分辨率较高,能够显示Schlemm’s管与Schwalbe线等细微结构;Visante OCT和傅里叶域实时眼前节OCT深层结构检测能力强,各设备所得生物学参数无明显差异.     

Comparison of ultrasound biomicroscopy and spectral-domain anterior segment optical coherence tomography in evaluation of anterior segment after laser peripheral iridotomy

AIM: To quantitatively assess narrow anterior chamber angle using spectral-domain anterior segment optical coherence tomography (SD-AS-OCT) and ultrasound biomicroscopy (UBM), and to evaluate the correlations and consistency between SD-AS-OCT and UBM. METHODS: Fifty-five eyes from 40 patients were examined. Patients were diagnosed with primary angle-closure glaucoma (PACG) remission (11 eyes from 8 patients), primary angle closure (PAC, 20 eyes from 20 patients) and PAC suspect (24 eyes from 12 patients). Each eye was examined by SD-AS-OCT and UBM after laser peripheral iridotomy (LPI). The measurements of SD-AS-OCT were angle open distance (AOD), anterior chamber angle (ACA), trabecular iris angle (TIA), and trabecular iris space area (TISA). UBM measurements were AOD and TIA. Correlations of AOD500 and TIA500 between UBM and AS-OCT were assessed. All parameters were analysed by SPSS 16.0 and MedCalc. RESULTS: ACA, TIA and AOD measured by SD-AS-OCT reached a maximum at the temporal quadrant and minimum at the nasal quadrant. TISA reached the maximum at the inferior and minimum at the superior quadrant. Group parameters of AOD500 and AOD750 showed a linear positive correlation, and AOD750 had less variability. UBM outcomes of AOD500 and TIA500 were significantly smaller than those of SD-AS-OCT. The results of the two techniques were correlated at the superior, nasal and inferior quadrants. CONCLUSION: Both UBM and SD-AS-OCT are efficient tools for follow-up during the course of PACG. We recommended using parameters at 750 µm anterior to the sclera spur for the screening and follow-up of PACG and PAC. The two methods might be alternatives to each other.     

Anterior segment changes during accommodation in eyes with a monofocal intraocular lens: high-frequency ultrasound study

PURPOSE: To analyze anterior segment structure changes during accommodative stimuli after monofocal intraocular lens (IOL) implantation using 2 ultrasound biomicroscopy (UBM) systems. SETTING: Department of Ophthalmology, University of Verona, Verona, Italy. METHODS: Twenty-six eyes (23 patients) with 1 of 4 monofocal IOL types were studied. Five to 9 months postoperatively, the patients were examined by high-frequency UBM using the HiScan system (Optikon 2000 SpA) and UBM 840 system (Carl Zeiss Meditec). Anterior chamber depth (ACD), iris-zonule distance, anterior chamber angle (ACA), scleral-ciliary process angle, and iris-ciliary process angle were measured using both systems. The iris-ciliary process distance and scleral spur perpendicular-sulcus distance were measured with the UBM 840 system and the sulcus-sulcus distance and capsular bag-IOL position with respect to ciliary process apex, with the HiScan system. Two experienced examiners performed all measurements. RESULTS: All parameters except the horizontal iris-ciliary process distance and vertical ACA measured by the UBM 840 system and horizontal ACA by the HiScan system showed significant variation during accommodation. An anterior shift of the IOL-capsular bag ciliary processes--sulcus-zonular iris complex was observed. A simultaneous centripetal shift of ciliary bodies and processes, shown by a reduction in sulcus and capsular bag diameter, was also observed. CONCLUSION: Anterior segment structures demonstrated accommodative movement on UBM after implantation of standard monofocal IOLs.     

Characteristics and reproducibility of anterior chamber angle assessment by anterior‐segment optical coherence tomography

Purpose: To evaluate the basic characteristics and reproducibility of anterior chamber angle (ACA) measurements determined by anterior‐segment optical coherence tomography (AS‐OCT) in open‐angle and primary angle closure suspect (PACS) patients. Methods: Thirty‐nine open‐angle and 18 PACS patients were imaged for ACA by AS‐OCT. Subjects underwent imaging of the nasal, temporal and inferior ACA under conditions of constant light, and darkness. For analysis, we used three ACA parameters handled by the Visante OCT software: angle opening distance at 500 μm (AOD₅₀₀), trabecular‐iris space area at 500 μm (TISA₅₀₀) and angle recess area at 500 μm (ARA₅₀₀). For determination of inter‐session reproducibility, a single well‐trained operator (D.Y.K.) scanned all patients at two different visits. For determination of inter‐operator variability, a second operator (S.B.P.) acquired another set of images independently. Three sets of images were acquired at least 24 hour apart. Results: All parameters were significantly different when measured both in light and darkness, and in the nasal and temporal quadrants. There were no significant differences between the left and right eyes in the three ACA parameters in all quadrants. The temporal angle was wider than the nasal and inferior angles. All parameters of the nasal, temporal angles had excellent inter‐session and inter‐operator reproducibility [intra‐class correlation coefficient (ICC) 0.796–0.981], but these values were slightly lower for inferior angle measurements (ICC 0.662–0.892) in both open‐angle and PACS groups. Conclusion: AS‐OCT provides quantitative and reproducible assessment of ACA. Reproducibility was lower in the inferior angle compared with the nasal and temporal angles, perhaps because of variable placement of the scleral spur.     

Reproduzierbarkeit der Goniometrie mittels spaltlampen-adaptierter optischer Kohärenztomographie

BACKGROUND: Visualization of the anterior chamber angle (ACA) is an important diagnostic part of evaluating patients with glaucoma. The purpose of this study was to evaluate the intra- and interobserver variability and reliability of the ACA and angle opening distance (AOD) measurements using optical coherence tomography (OCT). METHODS: To evaluate the intra- and interobserver variability, ACA and AOD were both measured five times and in three consecutive images in 22 patients (24 eyes) by two experienced observers. The intraclass correlation coefficient (ICC) as a measure of reliability was determined to estimate the intra- and interobserver variability. The main outcome measures were accuracy, reproducibility assessed with the coefficient of variation (CV), and the limits of agreement of ACA and AOD. RESULTS: The intraobserver variability of five replicate measurements was +/-1.4 degrees for ACA (CV 6.2%) and +/-11 micro m for AOD (CV 4%). The ICC for the intraobserver reliability was 0.99 for both ACA and AOD. The interobserver variability of three intersessional measurements was +/-2.5 degrees for ACA (CV 10.9%) and +/-24 micro m (CV 8.3%) for AOD. The ICC was 0.95 for ACA and 0.98 for AOD. There was no difference ( p>0.05) between the two observers measuring ACA and AOD. CONCLUSIONS: Two-dimensional visualization of the ACA and its assessment with slitlamp-adapted OCT yielded reliable ACA and AOD measurements in a clinical setting. Thus, OCT goniometry could provide an objective method to assess the anterior chamber angle.     

Quantitative comparison of Zeiss-Humphrey model 840 and Rion UX-02 systems of ultrasound biomicroscopy

· Background: Our objective was to estimate the agreement between two different ultrasound biomicroscopes (UBMs) and to evaluate the clinical implications of the measurements obtained. · Methods: We measured the anterior chamber depth, trabecular-iris angle, angle opening distance at 250 and 500 μm from the scleral spur, iris thickness and scleral-iris angle using the Humphrey UBM model 840 and Rion UBM UX-02 in 25 eyes of 25 normal volunteers. · Results: No significant difference was found in the mean values of any parameters measured by the Humphrey and Rion systems. Correlation coefficients of greater than 90% were observed for the parameters studied. Each system showed high reproducibility for all measured parameters. There were significant differences between the two systems in coefficients of variation for all parameters measured except the anterior chamber depth. · Conclusions: The parameters measured with the Humphrey and Rion systems showed correlation coefficients of greater than 90%. The Humphrey system showed better reproducibility than the Rion system. Received: 27 February 1998 Revised version received: 23 July 1998 Accepted: 21 September 1998     

A prospective ultrasound biomicroscopy evaluation of changes in anterior segment morphology after laser iridotomy in Asian eyes

PURPOSE: To prospectively quantify changes in anterior segment morphology after laser iridotomy using gonioscopy and ultrasound biomicroscopy (UBM). DESIGN: Prospective comparative observational case series. PARTICIPANTS: Fifty-five fellow eyes of patients presenting with acute primary angle closure (APAC). METHODS: The fellow eyes of patients presenting with APAC were examined with UBM, A-scan ultrasonography, and optical pachymetry at presentation and 2 weeks after sequential argon/neodymium yttrium-aluminum-garnet laser peripheral iridotomy (LPI). UBM images were analyzed using UBM Pro 2000 software. Baseline measurements were made both under standard lighting conditions and in darkness to look for changes in anterior segment findings. MAIN OUTCOME MEASURES: The degree of angle opening was measured using the angle-opening distance (AOD) at 250 and 500 microm from the scleral spur (AOD250 and AOD500, respectively) and angle recess area (ARA). RESULTS: Fifty-five Asian patients were examined; AOD250, AOD500, and ARA all significantly increased after sequential laser iridotomy (P < 0.002). Gonioscopic grading of the angle opening significantly increased in all 4 quadrants (P < 0.001). The Van Herick grade of limbal anterior chamber depth increased (P < 0.001), whereas the number of eyes classified as occludable decreased (73%-33%, P < 0.001). Anterior chamber depth did not change significantly (2.41 mm +/- 0.28 mm vs. 2.42 mm +/- 0.30 mm, P = 0.43) as measured with optical pachymetry. Increased illumination increased the angle-opening measures, but induced a different alteration in peripheral iris morphology. Illumination-induced changes were greater after iridotomy than before laser treatment. CONCLUSIONS: In Asian eyes at high risk of developing APAC, sequential LPI produced a significant widening of the anterior chamber angle without deepening the anterior chamber centrally. LPI produces changes in iris morphology that are different from those caused by an increase in illumination, indicating that different mechanisms account for angle opening under these 2 conditions.     

Ultrasound biomicroscopic study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation

PURPOSE: To report quantitative changes in the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation by means of ultrasound biomicroscopy (UBM). DESIGN: Prospective, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS: Twenty-one eyes of 19 patients with senile or presenile cataracts and no other ocular illness. METHODS: Patients were examined with UBM before and 1 and 3 months after surgery. At each UBM examination, axial images of the anterior chamber and radial sections of the angle at the superior, lateral, inferior, and medial quadrants were obtained. MAIN OUTCOME MEASURES: Central anterior chamber depth (ACD), iris-lens contact distance, iris-lens angle (ILA), angle opening distance at points 250 (AOD250) and 500 microm (AOD500) from the scleral spur, trabecular-iris angle (TIA), iris thickness 500 microm from the scleral spur (IT), trabecular-ciliary process distance (TCPD), iris-ciliary process distance (ICPD), iris-zonule distance, iris-sclera angle (ISA), and ciliary process-sclera angle (CPSA). After surgery, central anterior chamber depth was also measured from the cornea to the IOL (ACD) and from the cornea to the pupillary plane (ACD2). Each variable was measured twice in different days by the same observer. RESULTS: The variables IT, TCPD, ICPD, IZD, and CPSA did not significantly change after surgery (P > 0.01). Central anterior chamber depth increased approximately 30% after surgery (approximately 850 microm; P < 0.001), by both measurement methods used (ACD x ACD and ACD x ACD2). Anterior chamber angle significantly increased, by approximately 50% of the initial value, by the three measurement methods used: AOD250 (P 相似文献   

Increasing the size of a small peripheral iridotomy widens the anterior chamber angle: an ultrasound biomicroscopy study

PURPOSE: A peripheral iridotomy (PI) is the treatment of choice for pupillary block. In this study we investigated the effect of enlarging the size of a small PI on the anterior chamber angle in patients with angle closure using ultrasound biomicroscopy (UBM). PATIENTS AND METHODS: Patients who had been treated with laser peripheral iridotomy for angle closure and were identified to have a small patent PI (< 100 microm) with still appositionally closed anterior chamber angle were selected prospectively. The anterior chamber angle was assessed using UBM. The angle opening distance 500 microm from the scleral spur (AOD500) as well as the anterior and posterior chamber depth (ACD and PCD) 1000 microm from the scleral spur was measured. In addition, the ACD/PCD ratio was calculated. Afterwards, the PI was enlarged using an Nd: YAG laser and the UBM measurements were repeated as described above. RESULTS: Six eyes of six patients were examined. After the enlargement of the PI the average AOD500 increased from 109 microm (+/- 36) to 147 microm (+/- 40) (p < 0.05). The ACD/PCD ratio increased from 0.36 (+/- 0.065) to 0.67 (+/- 0.185) (p < 0.05). CONCLUSION: Patients with a small PI and appositionally closed anterior chamber angle should have a repeated laser treatment. The ACD/PCD ratio, measured 1000 microm from the sclerl spur, is a new method to describe the features and changes of the anterior chamber angle taking into account the configuration of the iris and the posterior chamber depth.