超声生物显微镜暗室激发试验

目的 比较超声生物显微镜（ＵＢＭ）暗室激发试验与传统暗室激发试验在闭角型青光眼筛选中的应用价值。方法 选择２２例（２２只眼）先兆期闭角型青光眼作为患者组,１５例（３０只眼）深前房正常者作为对照组,分别进行传统暗室试验和ＵＢＭ暗室试验。比较两种暗室试验前后房角的变化与眼压差,采用统计学χ＾２检验比较两者的阳性率。结果 两种暗室试验结果显示,闭角型青光眼组２２只眼中,１０只眼试验前后眼压差〉１．０７ｋ     

原发性闭角型青光眼周边虹膜切除前后房角相关结构的研究

目的：探讨我国不同类型原发性闭角型青光眼对周边虹膜切除术的反应,对不同房锄头 闭机制的闭角青光眼寻找合理的治疗方案。方法：采用房角检查技术,超声生物显微镜眼前段活体结构检查技术,ＵＢＭ暗室试验技术,ＵＢＭ眼前段图像处理技术,对不同类型闭角型青光眼周边虹膜切除术前后的房角状态,房 关解剖结构进行了定性及半定量观察,结果：周边虹膜切除术后,房角ＵＢＭ检查发现,临床经过呈慢性经过的闭青（慢闭）,特别是房     

Appositional angle closure in narrow angle eyes

Primary angle closure glaucoma (PACG) is a vision-threatening type of glaucoma. A high prevalence of PACG has been reported in the Asian region. In this review article, we would like to introduce novel findings on appositional angle closure, which plays an important role in the processes of PACG, based upon a new classification. Also, our studies of narrow angle eyes with the use of ultrasound biomicroscopy(UBM) revealed interesting features of appositional angle closure. Our studies showed that appositional angle closure was found frequently in dark conditions, and also that the width and location of the angles examined were significantly related to the presence of appositional angle closure. The use of UBM enabled us to observe physiologic changes in the angle structure in dark conditions, and provided us important information on the pathogenesis of PACG.     

明暗光线下超声活体显微镜检查在发现前房角关闭中的作用

目的 探讨明、暗光线下超声活体显微镜(UBM)检杳在发现前房角关闭中的作用.方法 系列病例研究.选择50岁及以上的浅前房和具有解剖的窄前房角人群作为研究对象.应用Van Herick法对受检人群进行周边前房深度检杳,对其中周边前房深度≤1/3角膜厚度者进行前房角镜检查,确定是否为解剖的窄前房角者.对解剖的窄前房角患眼进行明、暗光线下UBM检查,分别观察受检眼上方、颞上方、颞侧、颞下方、下方、鼻下方、鼻侧和鼻上方8个检查部位有无前房角关闭,评估具有解剖的窄前房角患眼前房角关闭率.从UBM图像中测量前房角开放距离.应用SPSS 12.0统计软件包,对研究数据进行分析.明、暗光线下前房角关闭率比较采用配对X2检验,前房角开放距离的比较采用Wilcoxon检验,以P<0.05作为差异有统计学意义.结果 符合入选条件的共有194例(379只眼)患者.以受检眼计算,在明、暗光线下UBM检杏发现的前房角关闭率分别为26.1%和69.7%,显示暗光线下前房角关闭率明显增高,两者间差异有统计学意义(X2=159.148,P=0.000).明、暗光线下均以上方的前房角关闭率最高,分别为21.4%和58.6%.周边前房深度越浅,前房角关闭率越高.周边前房深度<1/4角膜厚度眼在暗光线下前房角关闭率高达98.3%.在明或暗光线下,上、下、鼻、颞4个象限之间前房角开放距离的差异均有统计学意义(Z=-7.471,-15.407,-16.237,-16.782;P=0.000).上方象限前房角开放距离最小,前房角关闭率最高.结论 周边前房越浅,明、暗光线下前房角关闭率越高.明、暗光线下UBM检查是在临床和大规模人群中早期发现前房角关闭的有效和可行方法.(中华眼科杂志,2009,45:8-13)     

浅前房患者明暗环境条件下房角状态的变化

目的观察浅前房患者在不同光照条件下（暗室/明室）前房角状态的变化。方法研究对象为2007年1月至6月在我院眼科门诊就诊,符合下列条件者：裂隙灯周边前房深度≤1/4角膜厚度,压平眼压正常（≤21mmHg）,眼底视神经无典型青光眼性损害表现。超声生物显微镜（ultrasound biomicroscopy,UBM）检查采用先暗室后明室的顺序。按常规检查中央前房深度和12、3、6、9点方位的房角结构。结果共检查患者31例（62眼）,其中男性5例,女性26例。中央前房深度：右眼为（1.98±0.21）mm,左眼为（1.95±0.20）mm。房角相贴关闭眼的比例：在暗室检查中,左、右眼均有18眼检出房角关闭（占58.1%）;在明室检查中,右眼检出6眼（占19.3%）,左眼检出3眼（占9.7%）,双眼均在明室下出现关闭的有2例（占6.5%）;而无论明、暗环境,双眼中至少有一个方位检出房角相贴关闭的有25例（占80.6%）。结论浅前房患者,应用UBM检查,在暗室状态较明室状态下,房角更多发生相贴关闭。     

Long ciliary processes with no ciliary sulcus and appositional angle closure assessed by ultrasound biomicroscopy

PURPOSE: Nonpupil block mechanisms and appositional angle closure after laser iridotomy (LI) have been reported as common findings in Asians. We evaluated the presence of these findings in a cohort of Brazilian patients using ultrasound biomicroscopy (UBM). METHODS: This observational case-control study included 22 open angle eyes and 31 eyes with occludable angles on gonioscopy (defined by 2 examiners). UBM radial scans through a typical ciliary process were obtained in both light and dark conditions, at 6 and 12-o'clock positions. Long ciliary processes with no ciliary sulcus were determined on the basis of a reference line drawn perpendicular to the iris plane passing through a point located 750 mum from scleral spur. Trabecular ciliary processes distance was measured on 6-o'clock UBM images. RESULTS: After LI, 52% of occludable angle eyes had appositional angle closure in both 6 and 12-o'clock UBM images. We also observed this finding in 14% and 23% of the control eyes (in 6 and 12-o'clock UBM images, respectively). A long ciliary process with no ciliary sulcus was observed in 61% of occludable angle eyes, and also in 32% of control eyes (6-o'clock UBM images). Control eyes had longer trabecular ciliary processes distance than occludable angle eyes (P<0.001). CONCLUSIONS: The UBM finding of long ciliary processes associated with the absence of ciliary sulcus is not necessarily related to an anterior positioning of the ciliary processes. Whether UBM appositional angle closure after LI is associated with further angle closure process and/or poor intra-ocular pressure control remains to be evaluated.     

Unusual presentation of angle-closure glaucoma treated by phacoemulsification

We report the case of a 70-year-old woman with a history of acute primary angle-closure glaucoma (PACG) in the left eye who, 2 hours after a fundus examination and mydriasis, experienced acutely elevated intraocular pressure (IOP) up to 40 mm Hg in the presence of fully dilated pupil and a patent iridotomy. Gonioscopy revealed appositional angle closure in 3 quadrants. After medical control of the IOP, sutureless cataract surgery was performed, including clear corneal incision, phacoemulsification, and soft acrylic posterior chamber intraocular lens (IOL) implantation. Eighteen months after the operation, improvement of visual acuity, widening of anterior chamber angle, and deepening of anterior chamber depth were found. Intraocular pressures are now normal without medication, even after mydriasis. Modern cataract surgery is an effective treatment for selected patients with appositional angle closure and IOP elevation after acute PACG.     

激光周边虹膜切除术治疗原发性闭角型青光眼的远期疗效观察

目的 探讨激光周边虹膜切除术(LPI)治疗原发性闭角型青光眼(PACG)的远期疗效及安全性.方法 回顾性系列病例研究.收集1992年4月至2002年10月实施LPI治疗且术后随诊时间达5年以上的PACG患者临床资料,根据患者LPI治疗前眼压、视乳头、视野、前房角等情况,将患眼重新分为3组:疑似原发性前房角关闭(PACS)组、原发性前房角关闭(PAC)组、原发性闭角型青光眼(PACG)组,分析LPI治疗后各组患者远期眼压控制、视力及并发症等情况.不同类型的原发性闭角型青光眼之间LPI治疗后眼压控制情况比较采用x~2检验.结果 共收集到符合条件的患者131例(251只眼),其中PACS组18只眼(7.2%),PAC组98只眼(39.0%),PACG组129只眼(51.4%),无法分类的6只眼(2.4%).PACS组、PAC组、PACG组患者LPI治疗后眼压控制满意率分别为88.9%(16/18)、38.8%(38/98)及10.9%(14/129),眼压控制不满意率分别为5.6%(1/18)、48.0%(47/98)及75.2%(97/129),眼压控制失败率分别为5.6%(1/18)、13.3%(13/98)及14.0%(18/129).3组患者LPI治疗后眼压控制情况的差异有统计学意义(x~2=59.08,P=0.000).251只眼中8只眼(3.2%)在LPI治疗后1周至16年发生青光眼急性发作.全部患者在随诊期间未发生大泡性角膜病变.结论 LPI治疗后PACG的眼压控制不如预期的那样好.在大多数青光眼中,LPI可以有效防止闭角型青光眼的急性发作.LPI治疗后PACG、PAC、PACS组患者均存在不同程度的眼压升高危险,需密切随诊,及时处理.     

Ultrasound biomicroscopy dark room provocative testing: a quantitative method for estimating anterior chamber angle width

PURPOSE: To describe a quantitative method for measuring the iridocorneal angle recess area, and, using this, to evaluate factors associated with appositional angle-closure during dark room provocative testing using ultrasound biomicroscopy (UBM). METHODS: All patients (178 patients, 178 eyes) with clinically narrow angles referred for UBM dark room provocative testing between September 1996 and March 1998 were enrolled in this study. Images of the inferior quadrant of the angle taken under standardized dark and light conditions were analyzed. The angle recess area (ARA) was defined as the triangular area demarcated by the anterior iris surface, corneal endothelium, and a line perpendicular to the corneal endothelium drawn from a point 750 microm anterior to the scleral spur to the iris surface. ARA, and acceleration and gamma-intercept of the linear regression analysis of the ARA were calculated. In the linear regression formula, y = ax + b, the acceleration a describes the rate at which the angle widens from the scleral spur; the y-intercept b describes the distance from the scleral spur to the iris. RESULTS: Under dark conditions, the angles in 99 patients (55.6%) showed evidence of appositional angle-closure during testing. ARA (0.11 +/- 0.04 vs. 0.15 +/- 0.05 mm2, P < .0001, Student t-test), acceleration a (0.22 +/- 0.15 vs. 0.26 +/- 0.17, P = .068), and y-intercept b (66 +/- 46 vs. 92 +/- 47 microm, P = .0003) were smaller in eyes that were occluded. In the eyes that were not occluded, y-intercept b showed no significant difference between light and dark conditions (P = .1, paired t-test), while acceleration a did (P < .0001). In the eyes that were occluded, both decreased significantly under dark conditions (P < .0001). CONCLUSIONS The ARA linear regression formula provides useful quantitative information about angle recess anatomy. The more posterior the iris insertion on the ciliary face, the less likely the provocative test will be positive.     

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.     

氩激光周边虹膜成形术治疗急性闭角型青光眼随访研究

目的:观察氩激光周边虹膜成形术在原发性闭角型青光眼急性发作期的作用,评价该治疗方法随访1a疗效的稳定性。方法:原发性闭角型青光眼第1次急性发作患者23例(23眼),局部予以10g/L毛果芸香碱滴眼液及5g/L噻吗心安滴眼液各1滴后,行氩激光周边虹膜成形术,眼压控制稳定后5~7d行激光周边虹膜切开术。观察氩激光周边虹膜成形术治疗前及治疗后2h;1,3,6,9,12mo眼压变化;观察相应时间点房角变化;术后1,3,6,9,12mo行暗室加俯卧激发试验。结果:氩激光周边虹膜成形术前平均眼压为69.43±8.22mmHg,术后2h眼压为15.74±3.09mmHg,随访期间患者未发生高眼压;术前所有23眼前房角镜检查可见前房角关闭,术后2h所有23眼静态前房角镜检查前房角增宽,小梁网可见范围增宽,随访期间各方房角无明显变化;所有患者术后1,3,6,9,12mo行暗室加俯卧激发试验均为阴性。结论:氩激光周边虹膜成形术治疗原发性闭角型青光眼急性发作期(不联合使用全身降眼压药物治疗)可迅速、有效、安全降低眼压,重新开放房角,随访1a疗效稳定。     

APAC对侧眼激光周边虹膜切除术后3min暗室激发试验的临床观察

目的:观察急性原发性房角关闭(acut primary angle colsure,APAC)对侧眼激光周边虹膜切除术(laser peripheral iridotomy,LPI)后3min超声生物显微镜(ultrsounic biomicroscopy,UBM)暗室激发试验的相关生物学参数,探讨可疑原发性房角关闭(primary angle closure suspect,PACS)患者LPI术后发生接触性房角关闭的风险因素.方法:选择78例 APAC 对侧眼(无周边虹膜前粘连)为研究对象,LPI术后进行3min UBM暗室激发试验,观察中央前房深度(ACD)、房角开放距离(AOD500)、周边虹膜厚度(IT)、虹膜膨隆度(IC)、虹膜根部附着位置、小梁网睫状突距离(TCPD)等各项眼前节结构参数及房角接触性关闭方位数(NPAC) 并进行统计学分析.结果:LPI术后暗室下UBM检查至少1个方位发生接触性房角关闭的有26眼(33%),其中3min UBM暗室激发试验阳性的有19眼(24%),暗室激发试验时眼压升高值与接触性房角关闭的方位数呈正相关(r=0.84,P<0.01).接触性房角关闭(+)组与接触性房角关闭(-)组暗室时与正常光线下比较AOD500、IT、IC变化值有显著统计学意义(均P<0.01).单因数Logistic回归分析表明,AOD500(P=0.003)、IT(P=0.012)、IC(P=0.043)、TPCD(P=0.015)、虹膜根部附着位置(P=0.024)是暗室下接触性房角关闭(+)的相关因素;多因素Logistic回归分析表明IT(P=0.011)、TPCD(P=0.009)和虹膜根部附着位置(P=0.02)是暗室下接触性房角关闭(+)的独立相关因素.结论:PACS患者行LPI术后仍有部分在暗室下发生接触性房角关闭,虹膜周边肥厚、睫状体前位、虹膜根部附着点前移是重要的风险因素,在LPI术后应当进行长期随访与干预治疗.     

Inadvertent corneal indentation can cause artifactitious widening of the iridocorneal angle on ultrasound biomicroscopy

A 70-year-old Asian female with narrow angles underwent ultrasound biomicroscopy (UBM) darkroom provocative testing. The angle was narrow under light conditions and occluded in the dark, except for the inferior quadrant where the angle was wide and the iris concave. This was reproducible in four quadrants with the use of a small UBM eye cup but not the large one. A small eye cup can indent the cornea, resulting in artifactitious angle widenening. Care must be taken when using the small eye cup not to press on the cornea.     

急性原发性房角关闭对侧眼激光周边虹膜切除术后接触性房角关闭的研究

目的了解急性原发性房角关闭（APAC）对侧眼激光周边虹膜切除术（LPI）后接触性房角关闭的发生率和眼部解剖特征。方法前瞻性研究。选择54例APAC对侧眼没有虹膜前黏连（PAS）的患者作为研究对象,平均年龄（67．1±7．2）岁（54—83岁）。采用超声生物显微镜（UBM）在暗环境下观察LPI后是否发生接触性房角关闭．并比较发生接触性房角关闭与不发生接触性房角关闭患眼的眼压、房角及各项UBM参数,包括房角开放距离。（AOD跏）、房角隐窝面积,。（ARA750）、小梁虹膜夹角（T—I角）、小梁睫状体距离（TCPD）、周边虹膜厚度（IT1）、虹膜悬韧带距离（IZD）、虹膜根部附着位置、中央前房深度（ACD）。对两组数据采用独立样本t检验及两样本秩和检验进行分析。结果LPI后暗环境下UBM检查至少一个象限发生接触性房角关闭的有20例,占37％。反映房角开放程度的指标（AOD500、ARA750、T-I角）和反映睫状体位置的指标（TCPD）：接触性房角关闭（＋）组小于（-）组（t=11．741、11．089、12．175、4．349,P均〈0．01）;反映虹膜形态和位置的指标IT1：接触性房角关闭（＋）组大于（-）组（t=-3．300,P=0．002）;IZD、虹膜根部附着位置及ACD比较,两组差异无统计学意义（t=-1．880,P=0．066;Z=-1．423,P=0．155;t=0．072,P=0．942）。结论APAC对侧眼LPI后在暗环境下仍有一定比例发生接触性房角关闭,房角窄、睫状体前位、周边虹膜厚是LPI后发生接触性房角关闭的解剖学特点,提示LPI后具有这些解剖特点的APAC患者有可能进展为慢性房角关闭。     

白内障超声乳化吸除术治疗原发闭角型青光眼疗效观察

目的 观察单纯白内障超声乳化吸除联合后房型人工晶状体植入术对闭角型青光眼的治疗作用.方法 回顾性分析自2005年3月至2007年3月手术的闭角型青光眼合并白内障患者26例(32只眼),按照其房角关闭粘连状态分为2组,A组20只眼,房角关闭粘连≤1/2周,B组12只眼,房角关闭粘连＞1/2周,常规术前术后测量视力,最佳矫正视力,眼压,超声生物显微镜,中央前房深度,Goldman前房角镜检查.均在眼压得到最大控制后行单纯白内障超声乳化吸除联合后房型人工晶状体植入术.结果 视力两组术后均有不同程度提高.术后两组中央前房深度明显增加.UBM和前房角镜观察房角不同程度开放加宽,周边前粘范围缩小,部分房角重新开放.全部开放12只眼(A组),房角粘连关闭≤1/4周8只眼(A组4只眼B组4只眼),1/4＜房角粘连关闭≤1/2周8只眼(A组4只眼,B组4只眼),1/2＜房角粘连关闭≤3/4有3只眼(B组),房角粘连关闭≥3/4 1只眼(B组).眼压:B组术前术后比较有明显变化,具有统计学意义.但组间没有统计学意义.其中,B组1例2只眼术后一周内眼压再次升高,药物控制不理想,术后8周行小梁切除术控制眼压正常.结论 单纯白内障超声乳化吸出术对于房角关闭范围≤1/2周且术前药物控制良好不伴有视野损害的闭角型青光眼具有确切疗效.尤其对于首次发作的急性闭角青光眼有效.但对于术前房角粘连关闭范围≥1/2周且用药后控制眼压不理想伴有视野损害者,单纯晶体摘除,术后可能青光眼复发,需要长期随诊,且需联合小梁切除可有确切疗效.     

Evaluation of the efficacy of laser peripheral iridoplasty in reversing the darkroom provocative test result in Chinese patients with primary angle closure status post laser iridotomy

AIM: To investigate the efficacy and safety of krypton laser peripheral iridoplasty (LPIP) for Chinese patients with primary angle closure (PAC) or primary angle-closure glaucoma (PACG) status post laser iridotomy in reversing the positive results of the dark room provocative test (DRPT).METHODS:This study was prospective, noncomparative, interventional case series. Thirty-three patients (thirty-eight eyes) with PAC or PACG status post patent laser iridotomy and maintained normal intraocular pressure (IOP) but with positive DRPT results were enrolled. All the subjects were treated with krypton LPIP. DRPT was repeated after krypton LPIP. Results of DRPT were recorded. The visual acuity, IOP and gonioscopy were analyzed before and after krypton LPIP. A minimum time limit for follow-up was 6mo.RESULTS:Thirty-three patients (thirty-eight eyes) were followed for 17.7±8.37mo (range 7-41mo) after LPIP. Positive results of DRPT decreased from 38 eyes to 9 eyes (23.7%) after LPIP. Peripheral anterior synechiae of angle in 34 of 38 eyes (89.5%) remained unchanged at dynamic gonioscopy throughout the follow-up period after LPIP.CONCLUSION:LPIP decreased positive rates of the DRPT significantly. The mechanism may be that LPIP minimized contact between the peripheral iris and trabecular meshwork, which is a key factor for developing peripheral anterior synechiae.     

激光周边虹膜切开术对原发性闭角型青光眼高危者的二年干预效果

目的 观察激光周边虹膜切开术（laser peripheral iridotomy,LPI）对原发性闭角型青光眼（primary angle clouse glaucoma,PACG）高危者的2年干预效果。设计 队列研究。研究对象 PACG高危者52例（104眼）。方法 PACG高危者随机分成干预组和观察组两组,每组26例（52眼）,干预组行LPI, 观察组仅随访观察。于LPI术前、术后2周、6及12个月、2年进行眼科常规检查及超声生物显微镜（UBM）检查。主要指标 眼压、UBM图像中前房角参数。结果 干预组LPI术前眼压为（16.89±3.01） mm Hg,最后随访眼压为 （15.20±2.39） mm Hg;LPI术后中央前房深度、房角开放距离、小梁虹膜夹角、房角开放象限数均较术前增加,差异均有显著性（P均<0.01）。观察组随访1年时眼压变化无显著差异,但房角开放距离、小梁虹膜夹角、房角开放象限数均较前减少,差异均有显著性（P均<0.05）;随诊2年时眼压（17.31±2.27）mm Hg,  较前增高（P<0.05）。干预组无一例发展为PACG,观察组2例（2眼）PACG急性发作。 结论 LPI能有效改善前房角结构,并可有效防止PACG高危者发展为PACG。     

An evaluation of the darkroom prone provocative test in family members of primary angle closure glaucoma patients

PURPOSE: To compare ocular biometric parameters with darkroom prone provocative test (DRPPT) in family members of primary angle closure glaucoma (PACG) patients. METHODS: One hundred and forty-nine family members of 46 PACG patients underwent ocular examination included slit lamp biomicroscopy, gonioscopy, fundus examination using +90 D lens, Goldmann applanation tonometry, darkroom prone provocative test, perimetry on Humphrey's field analyzer II and optic disc evaluation using HRT II. Ultrasonic ocular biometry and the DRPPT were then performed. IOP>or=8 mmHg rise from baseline with iridocorneal touch was considered as a positive test. RESULTS: Of the 149 family members examined, 55 (36.9%) were found to have PACG. Forty (72.7%) of these had subacute PACG and 15 (27.3%) were found to have chronic PACG. Thirty-nine (70.3%) of the affected members showed a positive DRPPT. Mean anterior chamber depth (ACD) was 2.03+/-0.3, 2.3+/-0.4, 2.7+/-0.3 mm (P=0.0001) and mean lens thickness was 4.41+/-0.39, 3.99+/-0.5, 3.93+/-0.4 mm (P=0.0001) in DRPPT positives, borderlines and negatives respectively. ROC curve (ACD) plotted showed cutoff value of 2.07 mm (sensitivity 88.57%) for screening. CONCLUSION: Anterior chamber is shallowest, lens is thickest and axial length is shortest in affected and DRPPT positive, family members of PACG patients.     

Prevalence of plateau iris configuration in primary angle closure glaucoma using ultrasound biomicroscopy in the Indian population

Purpose:

To report the prevalence of plateau iris in patients with primary angle closure glaucoma (PACG), in North India.

Materials and Methods:

The patients with PACG, attending the glaucoma services at a tertiary care center in North India were included in the study. All patients had undergone Nd-YAG laser peripheral iridotomy at least four weeks prior to inclusion in the study. Four weeks prior to inclusion in the study, none of the patients had used pilocarpine. Ultrasound Biomicroscopy (UBM) images were qualitatively evaluated and plateau iris configuration was defined in an eye if the following criteria were fulfilled in two or more quadrants: anteriorly directed ciliary process supporting the peripheral iris, steep rise of iris root from its point of insertion followed by a downward angulation from the corneoscleral wall, absent ciliary sulcus, and iridotrabecular contact in the same quadrant.

Results:

One hundred and one eyes were included in the study. There were 63 (62.4%) females and 38 (37.6%) males. The mean age of the patients was 57.8 ± 9.5 years (range: 42 to 78 years). The mean axial length in the study population was 22.2 ± 1.1 mm. The mean spherical equivalent refraction was 0.06 ± 1.12 D. The mean intraocular pressure was 18.5 ± 4.7 mmHg (range: 12 – 24 mmHg). Twenty-nine (28.7%) subjects were diagnosed with plateau iris on the basis of above-defined criteria. Of the 29 eyes, 18 (62.1%) subjects had plateau iris in two quadrants, nine (31.03%) in three quadrants, and two (6.8%) had this configuration in all the four quadrants.

Conclusions:

Approximately 30% of the eyes with PACG had plateau iris on UBM. Plateau iris was very often the cause for residual angle closure following laser peripheral iridotomy in Indian eyes with PACG.     

Primary lens extraction for glaucoma management: A review article

Recently, primary lens extraction alone gained more acceptance as an alternative surgical approach for glaucoma management. This view was supported by the advances in phacoemulsification and intraocular lenses with greater safety and visual recovery, in addition to a substantial reduction of intraocular pressure and deepening of the anterior chamber and filtration angle. The decrease in IOP after cataract surgery in primary open-angle glaucoma (POAG) is mild, less predictable, related to baseline levels, and may return to presurgical values after an initial period of reduction. Therefore, the IOP-lowering effect of primary cataract extraction in POAG may be insufficient to achieve adequate IOP control. The IOP reduction after lens extraction is consistently greater in eyes with primary angle closure glaucoma (PACG) than in eyes with POAG. Primary lens extraction in acute PACG eliminates, or at least, reduces the risk of recurrence of acute attacks and deepens the anterior chamber and widens the angle which reduces the risk of progression of peripheral anterior synechiae and development of chronic PACG. Primary lens extraction may be more preferable to glaucoma incisional surgery in mild to moderate PACG eyes with appositional angle closure. The decision to do lens extraction as a primary treatment for glaucoma should be individualized based upon several factors other than the effect on IOP. These factors include patients’ characteristics, surgeons’ skills and preferences, status of glaucoma control, type of cataract and intraocular lens implanted, and potential harm of laser treatment for late capsular opacification and fibrosis.