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.     

正常人裂隙灯光学相干断层成像测量前房角参数分布

目的利用裂隙灯光学相干断层成像术（SL-OCT）对正常志愿者前房角各参数进行初步研究,讨论其变化规律。方法选择正常志愿者52例102眼使用海德堡SL-OCT进行眼前节测量,对房角开放距离（AOD）500μm、750μm,及2个AOD情况下的小梁-虹膜空间面积（TISA）、房角隐窝面积（ARA）、房角角度（ACA）4个反映房角开放程度的参数进行研究。结果各参数500μm系列变异较750μm系列大;反映房角开放程度的各参数值在上方象限较小,鼻上方最小,下方象限较大,以颞下象限最大;房角各测量值随着年龄的增加逐渐变小,但60岁后有增加趋势。结论在SL-OCT测量的反映房角开放的AOD、TISA、ACA、ARA4个参数中,ARA对房角开放程度的反映较其他参数差,500μm系列参数的变异性较750μm系列大,正常人房角左右眼各参数无差异,上方象限房角较窄,下方象限较宽,并且随着年龄的增加,正常人房角变窄,50～60岁时最窄,60岁后房角有加宽趋势。     

频域眼前段光学相干断层扫描对周边虹膜切除术前后前房角的研究

目的应用频域眼前段光学相干断层扫描（OCT）分析周边虹膜切除术前后前房角的变化。方法原发性前房角关闭者32例（40只眼）行周边虹膜切除术,术前、术后2d、2个月使用频域眼前段OCT进行前房角测量,比较500μm／750μm前房角角度（ACA500／ACA750）和500μm／750μm前房角开放距离（AOD500／AOD750）等指标。结果各指标在术前、术后差异有统计学意义,术后2d、2个月相应指标差异无统计学意义。结论原发性前房角关闭行周边虹膜切除术后前房角增宽,可缓解瞳孔阻滞,预防前房角进一步关闭,频域眼前段OCT可进行术前术后的非接触检查,实现前房的生物统计学测量。     

超声乳化联合房角分离治疗房角广泛粘连的AACG合并白内障

目的：评估广泛房角粘连的急性闭角型青光眼(AACG)合并白内障患者行超声乳化白内障摘除、人工晶状体植入联合房角分离术(PEI+GSL)的临床疗效。

方法：采用回顾性研究,选取我院2018-01/2019-06收治的AACG合并白内障患者32例35眼,房角粘连关闭的范围均≥180°,所有患者均行PEI+GSL,观察术后1d,1wk,1、3mo最佳矫正视力(BCVA)、眼压、中央前房深度(ACD)、房角开放距离(AOD₅₀₀)、小梁虹膜面积(TISA₅₀₀),术后1、3mo的房角关闭范围、盘周视网膜神经纤维厚度(RNFL)及并发症情况。

结果：术后3mo, BCVA(0.334±0.154),眼压(14.63±3.59mmHg)较术前(0.914±0.290,42.54±8.06mmHg)改善(P<0.05); ACD(3.203±0.214mm)及鼻侧、颞侧OCT房角参数AOD_500、TISA₅₀₀(0.308±0.014、0.315±0.015mm、0.134±0.013、0.139±0.018mm²)较术前均明显增加,房角镜下房角关闭范围(72.32°±28.33°)较术前(215.29°±30.66°)减少,盘周RNFL较术前变薄(P<0.001)。术后3mo鼻侧、颞侧AOD₅₀₀、TISA₅₀₀变化量与眼压存在负相关性,但与ACD变化量无相关性,术后3mo无明显并发症发生。

结论：应用PEI+GSL治疗广泛房角粘连的AACG合并白内障患者可以改善视力,早期加深前房,有效促进房角开放,从而降低眼压。     

急性闭角型青光眼对侧眼与可疑原发房角关闭眼的前节参数比较

目的：探讨原发闭角型青光眼单侧急性发作( acute angle closure glaucoma,AACG)的对侧眼、可疑原发房角关闭眼(primary angle closure suspects,PACS)和正常眼的前节生物学参数差异。
　　方法：采用光学相干断层扫描( optical coherence tomography,OCT)和 Pentacam 三维眼前节分析诊断系统(pentacam scheimpflug system,Pentacam)完成26例26眼AACG对侧眼及与之年龄、性别匹配的28例28眼PACS和34例34眼正常眼的前节扫描。采用Pentacam获得以下参数：中央角膜厚度( CCT)、角膜容积( CV)、瞳孔直径( PD)、中央前房深度( CACD)、周边前房深度( PACD)、前房容积( CV )和房角度数( ACA )。应用图像处理软件和OCT测量虹膜厚度(IT750,IT2000),面积(IS)、体积(IV)和房角开放距离500( AOD500)进行。
　　结果：角膜参数(CCT,CV),PD、虹膜参数(IT750,IT2000, IS,IV)无统计学差异( P>0.05)。与 AACG 对侧眼和PACS比较,正常人CACD和PACD更深, ACV更大, ACA和AOD500更宽敞( P<0.05)。 AACG对侧眼和PACS相比,各项前节解剖参数均无统计学差异(P>0.05)。以AACG对侧眼作为房角关闭好发的诊断标准,上述前房参数的受试者工作特征曲线下面积均小于0.7。
　　结论：AACG对侧眼和PACS的前节生物学参数无显著差异,以此作为房角关闭好发的诊断精准度较低。     

巩膜瓣下应用黏弹剂对青光眼白内障联合术后前房的影响

目的：研究闭角型青光眼急性发作的白内障患者行青光眼白内障联合术中巩膜瓣下应用黏弹剂对术后前房的影响。

方法：前瞻性研究。选取我院2016-08/2018-08采用青光眼白内障联合术治疗青光眼急性发作的白内障患者，随机分为应用黏弹剂组和常规手术组，分别于术后1、3、7d应用眼前节OCT测量前房深度(ACD)、巩膜突前500μm房角开放距离(AOD₅₀₀)、虹膜小梁网夹角(TIA)和眼压。

结果：术后1、3、7d，前房结构参数应用黏弹剂组为：ACD：3.82±0.51，3.71±0.63，3.78±0.33mm； AOD_500：0.25±0.04，0.24±0.04，0.25±0.05mm； TIA：32.01°±7.71°，31.36°±5.61°，31.82°±7.53°； 常规手术组为：ACD：2.71±0.29，3.21±0.43，3.60±0.57mm； AOD_500：0.20±0.08，0.21±0.05，0.24±0.07； TIA：25.13°±8.06°，26.18°±8.06°，29.25°±6.22°。其中术后1、3d ACD、AOD_500、TIA，两组患者有差异(P<0.05)； 而术后7d无差异(P>0.05)。两组患者术后眼压均显著降低至20mmHg以下，术后1d应用黏弹剂组眼压高于常规手术组(P<0.05)； 术后7d两组患者眼压无差异(P>0.05)。

结论：青光眼白内障联合手术中巩膜瓣下应用黏弹剂，能有效加深术后早期前房，术后眼压稳定，具有避免术后早期浅前房发生，维持房角开放的作用。     

Light–dark changes in iris thickness and anterior chamber angle width in eyes with occludable angles

Backgound

The purpose of this study was to investigate and measure light–dark changes in iris thickness (IT) and anterior chamber angle width in eyes with occludable angles and open angles by using anterior segment optical coherence tomography (AS-OCT).

Methods

We examined 153 eyes of 153 Japanese patients with primary angle closure suspect, primary angle closure, primary angle closure glaucoma, or primary open angle glaucoma. AS-OCT was used to determine pupil diameter, IT, angle opening distance at 500 μm (AOD₅₀₀), and trabecular-iris space area at 500 μm (TISA₅₀₀) in each quadrant of the anterior chamber angle (superior, inferior, temporal, and nasal) under light and dark conditions.

Results

In the angle closure cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark varied significantly among the four quadrants (P?<?0.05, analysis of variance). In contrast, in the open angle cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark did not differ significantly among the four quadrants. In the angle closure cases and the open angle cases, significant negative associations were found between IT difference [IT_(light)–IT_(dark)] and AOD₅₀₀ difference [AOD_500(light)–AOD_500(dark)] (R?=??0.411, P?<?0.001 and R?=??0.501, P?=?0.001, respectively) and between IT difference and TISA₅₀₀ difference [TISA_500(light)–TISA_500(dark)] (R?=??0.475, P?<?0.001 and R?=??0.462, P?=?0.002, respectively).

Conclusion

Our results suggest that thickening of the iris root under dark conditions is related to the mechanism of primary angle closure. It is important to analyze both the angle structure and peripheral IT in each quadrant.     

Clinical and Anterior Segment Anatomical Features in Primary Angle Closure Subgroups Based on Configurations of Iris Root Insertion

PurposeTo compare the clinical and anterior segment anatomical features in primary angle closure sub-groups based on configurations of iris root insertion.MethodsPrimary angle closure patients were imaged using anterior segment optical coherence tomography. Anterior chamber depth, iris curvature, iris thickness (IT) at the scleral spur and 500, 750, and 1,500 µm from the scleral spur (IT₀, IT₅₀₀, IT₇₅₀, and IT₁₅₀₀), lens vault, iris area, angle opening distance (AOD₅₀₀), angle recess area (ARA₇₅₀), and trabecular iris space area (TISA₇₅₀) were measured. Iris root insertion was categorized into a non-basal insertion group (NBG) and basal insertion group (BG).ResultsIn total, 43 eyes of 39 participants belonged to the NBG and 89 eyes of 53 participants to the BG. The mean age of participants was greater in the NBG than the BG (62.7 ± 5.7 vs. 59.8 ± 7.3 years, p = 0.043), and the baseline intraocular pressure was higher in the BG than the NBG (16.4 ± 4.4 vs. 14.9 ± 3.3 mmHg, p = 0.037). The BG showed a greater IT₀ (0.265 ± 0.04 vs. 0.214 ± 0.03 mm, p < 0.001) and iris area (1.59 ± 0.24 vs. 1.52 ± 0.27 mm², p = 0.045), lower ARA₇₅₀ (0.112 ± 0.08 vs. 0.154 ± 0.08 mm², p = 0.017) and AOD₅₀₀ (0.165 ± 0.07 vs. 0.202 ± 0.08 mm, p = 0.014) compared to the NBG.ConclusionsThe BG had a narrower anterior chamber angle, thicker peripheral iris, and higher pretreatment intraocular pressure.     

Evaluation of anterior chamber parameters with spectral-domain optical coherence tomography

Purpose

To evaluate several anterior chamber parameters in healthy young adults using spectral-domain optical coherence tomography and to describe the repeatability and reproducibility of this method.

Study design

Prospective clinical study.

Methods

Fifty-two eyes of 52 healthy volunteers were enrolled. Manual measurements of the anterior chamber angle (ACA₅₀₀ and ACA₇₅₀), angle opening distance (AOD₅₀₀ and AOD₇₅₀), angle-to-angle distance (ATA), anterior chamber width (ACW), and lens vault (LV) were obtained.

Results

The mean nasal ACA₅₀₀ was 44.87 ± 12.92°; ACA₇₅₀, 43.94 ± 10.41°; AOD₅₀₀, 672.54 ± 270.19 µm; AOD_750, 881.87 ± 290.55 µm. The mean temporal ACA₅₀₀ was 41.46 ± 11.20°; ACA₇₅₀, 41.27 ± 11.31°; AOD₅₀₀, 603.15 ± 232.28 µm; AOD_750, 823.46 ± 308.76 µm. The differences between the corresponding nasal and temporal parameters were statistically significant. The ACW was 11.97 ± 0.42 mm, the ATA was 12.10 ± 0.43 mm, and the LV was 3.71 ± 232.93 µm. The ACA was highly associated with the LV. The intraclass correlation coefficients ranged from 0.984 to 0.999 for the intraobserver repeatability and from 0.966 to 0.998 for the interobserver reproducibility.

Conclusions

This study assessed anterior chamber parameters in healthy young adults using spectral-domain optical coherence tomography. This technique reveals the spatial relationships of the ocular structures, provides high-resolution images, and results in high degrees of intraobserver and interobserver repeatabilities.

     

频域眼前节光学相干断层扫描仪(AS-OCT)对激光周边虹膜切开术后患者前房角结构定量检测

目的 利用频域眼前节光学相干断层扫描仪(anterior segment optical coherence tomography,AS-OCT)检测原发性闭角型青光眼及原发性房角关闭眼激光周边虹膜切开术后的房角参数,并探讨测量参数的选择及在青光眼患者筛查与随访中的临床意义.方法 选取原发性闭角型青光眼及原发性房角关闭患者共40例(55眼),其中原发性急性闭角型青光眼缓解期8例11眼,原发性急性闭角型青光眼临床前期20例(20眼),原发性房角关闭12例(24眼).应用频域AS-OCT量化评价激光周边虹膜切开术后房角结构,测量上方、下方、鼻侧、颞侧前房角(anterior chamber angle,ACA)、小梁虹膜夹角(trabecular-iris angle,TIA)、房角开放距离(angle open distance,AOD)、小梁虹膜空间面积(trabecular iris space area,TISA),对检查结果进行分析.结果 选取角膜内侧距巩膜突500 μm和750μm的点,分别测量上方、下方、鼻侧、颞侧四个方位的AOD、TIA、ACA、TISA,归为500系列和750系列.500系列及750系列TIA、ACA、AOD测量值均值均为颞侧最大,鼻侧最小;TISA测量均值下方最大、上方最小.Pearson相关性分析显示TIA500和ACA500(r=0.799、P=0.00)、TIA750和ACA750(r=0.799、P=0.00)、TIA500和TI-SA500(r=0.919、P=0.00)、TIA750和TISA750(r=0.920、P=0.00)均具有正相关关系.以TIA500为自变量x,TISA500为因变量y,得回归方程y=-0.300 +0.005x(F=1195,P=0.00),即TISA500与TIA500呈线性正相关关系.以TIA750为自变量x,TISA750为因变量y,得回归方程y=-0.440 +0.009x(F=854,P=0.00),即TISA750与TIA750呈线性正相关关系.750系列参数的变异系数在四个方位均小于500系列.结论 频域AS-OCT可用于原发性闭角型青光眼及原发性房角关闭患者术后的疗效评价与随访.在房角狭窄时,750系列参数变异系数更小,更具有临床应用价值.     

有晶状体眼后房型人工晶状体植入术后前房角的改变及相关因素分析

目的：探讨有晶状体眼后房型人工晶状体植入术后不同时间的前房角变化,分析影响术后前房角度数（ACA）的相关因素。方法：前瞻性非随机的连续病例研究。连续收集2018年9月至2019年2月在郑州大学第一附属医院眼科屈光中心接受有孔型有晶状体眼后房型人工晶状体（ICL）植入术的近视患者81例（81眼）,患者术前,术后1 d、1个月和6个月行Visante眼前段光学相干断层扫描（OCT）检 查,测量术前、术后鼻侧和颞侧ACA及术后拱高。分析术后ACA与术前等效球镜度（SE）、眼轴长度、水平角膜直径、前房深度、前房容积、水平角膜曲率、术前ACA、ICL直径和术后拱高的相关性。 采用重复测量方差分析比较患者不同时间点眼前段各项参数的变化,两两比较采用 Bonferroni检验。 相关性分析采用Pearson相关或Spearman相关分析。结果：术后1 d、1个月和6个月的ACA比较差异 均无统计学意义,术后的鼻侧ACA较术前减少45%～50%（F=268.73,P<0.001）,术后的颞侧ACA 较术前减少44%～49%（F=333.40,P<0.001）。ICL植入术后1 d、1个月和6个月的平均拱高分别为 （640±180）μm、（540±150）μm和（530±160）μm,差异具有统计学意义（F=54.14,P<0.001）;术后 1个月内拱高下降趋势明显,术后1个月至术后6个月期间拱高下降趋势明显减缓。 ICL植入术后鼻 侧ACA与术前前房容积、术前前房深度和术前ACA呈正相关（r=0.426,P=0.003;r=0.377,P=0.008; r=0.525,P<0.001）;与ICL直径、拱高、术前SE、眼轴长度、水平角膜曲率和水平角膜直径无相关性。 ICL植入术后颞侧ACA与术前前房容积、术前前房深度和术前ACA呈正相关（r=0.392,P=0.006; r=0.376,P=0.008;r=0.594,P<0.001）,与ICL直径、拱高、术前SE、眼轴长度、水平角膜曲率和水平角膜直径无相关性。结论：ICL植入术后前房角明显减小,随访期内患者前房角开放度数基本稳定, 没有进一步变窄。     

Changes in Caucasian eyes after laser peripheral iridotomy: an anterior segment optical coherence tomography study

Background: To evaluate by anterior segment optical coherence tomography (AS‐OCT) the changes in the anterior chamber structures in Caucasian eyes after laser peripheral iridotomy (PI). Methods: Retrospective study of consecutive Caucasian primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle closure glaucoma (PACG) patients who underwent laser PI over a 25‐month period at a specialist glaucoma practice. The AS‐OCT images of the temporal and nasal angles (in light and dark) before and after laser PI were analysed. The parameters studied were trabecular‐iris angle (TIA), angle opening distance (AOD), trabecular‐iris space area (TISA), trabecular‐iris contact length (TICL), iris thickness (IT) and maximum iris bow height (MIBH). Results: Images of 71 eyes of 71 patients were assessed. The mean age at laser PI was 60.3 ± 10.0 years. Forty (56.3%) were women, and 14 (19.7%) had PACG. The mean time from laser PI to the follow‐up AS‐OCT scan was 5.92 ± 3.22 weeks. The IT did not alter significantly after laser PI, but there were significant increases in the TIA, AOD and TISA, as well as a significant decrease in MIBH, in both light and dark. There was no difference in the magnitude of change seen between the temporal and nasal angles, or between PACS/PAC and PACG eyes. Conclusion: In Caucasian eyes, laser PI resulted in significant angle widening (increased TIA, AOD and TISA) and iris profile flattening (decreased MIBH) at the temporal and nasal angles based on AS‐OCT imaging in both light and dark.     

白内障超声乳化摘出术后OCT测量的眼前节结构改变

目前,白内障是世界上主要的致盲眼病,其次是青光眼.年龄相关性白内障未成熟期晶状体膨胀,构成闭角性青光眼发生的危险因素,及早进行白内障超声乳化摘出术是解决该危险因素的最佳手段.选择何时进行手术以及预后效果成为困扰临床医师的问题.本研究纳入17篇应用眼前节OCT(AS-OCT)分别对白内障超声乳化摘出术前后眼前节生物测量不同参数进行定量分析的文献,就白内障超声乳化摘出术对眼前节结构的影响进行综合评价.全部文献累计866患眼;随访时间为术后6个月.术后前房深度(ACD)、前房容积(ACV)、前房角度(ACA)、巩膜突起500 μm房角开放距离(AOD500)、AOD750、巩膜突起500 μm小梁与虹膜接触面积(TISA500)、TISA750、巩膜突起750μm房角隐窝面积(ARA750)均较术前不同程度升高,术后前房宽度(ACW)、巩膜突起750.μm处的虹膜厚度(IT750)均无明显变化,术后虹膜弯曲度(I-Curv)、虹膜横断面面积、虹膜突面积较术前降低.术前LT与术后ACD及术后TISA500均呈高度正相关.术前晶状体拱高(LV)与术后3个月ACD及术后3个月AOD500均呈正相关.综合文献证实,白内障超声乳化摘出术可解除瞳孔阻滞,减小虹膜压迫,使得前房加深和房角增宽.白内障超声乳化摘出联合人工晶状体植入术可用于青光眼的治疗,值得进一步推广.     

新型中央孔型有晶状体眼后房型人工晶状体植入术后前房角的变化

目的：观察新型中央孔型有晶状体眼后房型人工晶状体(ICL)V4c植入术矫正高度近视术后前房角的变化。

方法：前瞻性临床研究。选择高度近视患者150例300眼,均行ICL V4c植入术,记录术前及术后1d,1、3、6mo,1a的视力、眼压、拱高及前房角的变化。采用重复测量方差分析及LSD-t检验对数据进行分析。

结果：术后1d,1、3、6mo,1a,裸眼视力(UCVA)恢复情况较术前显著提高(F=98.2,P<0.01); 术前与术后各时间点鼻侧AOD500、AOD750、TISA500、TISA750、SSA比较均有差异(F=108.256、112.342、164.856、316.549、115.338,均P<0.01); 术前与术后各时间点颞侧AOD500、AOD750、TISA500、TISA750、SSA比较均有差异(F=102.68、548.47、93.37、316.549、117.698,均P<0.01); 两侧术后1d,1、3mo各房角参数逐渐降低,两两比较均有差异(P<0.05),术后3、6mo,1a各房角参数两两相比均无差异(P>0.05)。

结论：ICL V4c植入术后1d,1、3、6mo,1a水平方向各房角参数较术前变小,3mo后基本趋于稳定状态。     

超声乳化联合人工晶状体植入术对前房深度及房角宽度的影响

目的:探讨超声乳化联合人工晶状体植入术对患者前房深度、房角宽度的影响.方法:选取2015-06/2016-05在我院行白内障超声乳化吸除联合人工晶状体植入术的患者74例89眼,于术前及术后3 mo测量患者眼压、中央前房深度(ACD)、房角开放距离(AOD500)和房角角度(ACA500).结果:术后3mo,眼压为11.34±2.38mmHg,较术前(12.60±2.5 1mmHg)有所降低,差异有统计学意义(P＜0.05);ACD为4.01 ±0.30rmm,较术前(2.30±0.42mm)明显增厚,差异有统计学意义(P＜0.05);AOD500和ACA500分别为0.915±0.223mm和41.71 °±6.55°,明显高于术前0.514±0.201mm和24.01°±8.43°,差异有统计学意义(P＜0.05);眼压值与ACD、AOD500和ACA500呈负相关(r=-0.239、-0.211、-0.252,P＜0.05).结论:超声乳化联合人工晶状体植人术可降低患者眼压,增加患者前房深度和房角宽度,从而对眼内房水循环起到积极作用.     

白内障人工晶状体植入术前后角膜厚度和前房深度及前房角的改变

目的:探讨超声乳化白内障吸除折叠式人工晶状体植入术前后,术眼前房深度和角膜厚度及前房角结构的改变。方法:对20例20眼老年性白内障患者行超声乳化白内障吸除折叠式人工晶状体植入术,分别于术前和术后1wk使用超声生物显微镜量化测量前房深度、角膜厚度和前房角宽度。结果:全部患者术后1wk角膜厚度明显增加,前房深度明显增大;500μm处前房角开放距离(AOD500)及ACA角度均与术前值比较明显增加,且均P<0.01。结论:超声乳化白内障吸除折叠式人工晶状体植入术可以使角膜厚度显著增加;可显著增加老年性白内障患者的前房深度及房角宽度。     

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.     

Alteration of anterior chamber in 81 glaucomatous eyes using Pentacam Scheimpflug system

AIM: To study the effects of gender, eye side and age on anterior chamber measurements; To compare the anterior chamber parameters between glaucoma and normal subjects. METHODS: A total of 169 patients (299 eyes), of which 122 normal subjects (218 eyes), 24 cases (39 eyes) with primary angle-closure glaucoma (PACG) and 22 cases (42 eyes) with primary open-angle glaucoma (POAG) visiting our hospital from Apr. 2008 to Oct. 2008 were enrolled. The parameters measured by Pentacam between different sexes, eye sides, ages and different groups were compared. RESULTS: The mean central anterior chamber depth (CACD), anterior chamber volume (ACV) and anterior chamber angle (ACA) measurements of normal eyes were 2.82±0.43mm, 159.74±43.64mm3 and 35.47±7.92°. There were no significant differences between different eye sides. There was a negative correlation between age and anterior chamber parameters (all P <0.001); The mean CACD, ACV and ACA were 1.87±0.29mm, 82.00±24.17mm3 and 21.94±7.11° in PACG group, and 2.67±0.34mm, 147.24±43.40mm3 and 31.19±6.34° in POAG group. The differences between PACG and age-matched normal subjects were significant (all P <0.05), but there was no significant difference between POAG and age-matched normal subjects (P >0.05). CONCLUSION: CACD, ACV and ACA decrease mildly with age. Anterior chamber parameters of PACG are smaller than that of normal eyes, but there is no difference between POAG and normal eyes.     

Comparison of anterior chamber angle parameters and iris structure of juvenile open-angle glaucoma and pigmentary glaucoma

Purpose:To compare the quantitative measurements of the anterior chamber angle (ACA) and iris parameters in patients with juvenile open-angle glaucoma (JOAG), pigmentary glaucoma (PG), and healthy controls using anterior segment optical coherence tomography (AS-OCT).Methods:This was a retrospective, cross-sectional study of 25 eyes with JOAG, 25 eyes with PG, and 25 control eyes. Anterior chamber depth, angle-opening distance 500 and 750, trabecular–iris space 500 and 750, scleral spur angle, iris thickness (IT, measured at the thickest part), and iris bowing were obtained using AS-OCT (Visante” OCT 3.0 Model 1000, Carl Zeiss Meditec, Inc).Results:The quantitative ACA parameters were found to be significantly higher in JOAG and PG patients compared to healthy controls (P < 0.001); there was no significant difference between the eyes with JOAG and PG (P > 0.05). In eyes with JOAG and PG, there was significantly backward bowing of the iris in temporal and nasal angles compared to control subjects (P < 0.001). Median iris bowing was not significantly different between the patients with JOAG and PG (P > 0.05). The temporal and nasal angle iris thickness were significantly thinner in eyes with JOAG than the eyes with PG (P < 0.001) and age-matched control subjects (P < 0.001). The median IT did not differ between the patients with PG and control subjects (P > 0.05). In patients with JOAG, the intraocular pressure (IOP) was inversely correlated with IT (r = -0.43, P < 0.05).Conclusion:AS-OCT provided quantitative data on the ACA and iris parameters in JOAG and PG. The evaluation of the ACA and iris structures using AS-OCT revealed higher ACA measurements and posterior bowing of the iris in patients with JOAG and PG. Furthermore, the patients with JOAG were found to have thinner IT than the ones with PG and healthy controls.     

Novel Discoveries of Anterior Segment Parameters in Fellow Eyes of Acute Primary Angle Closure and Chronic Primary Angle Closure Glaucoma

PurposeTo investigate the biometric differences of anterior segment parameters between fellow eyes of acute primary angle closure (F-APAC) and chronic primary angle closure glaucoma (F-CPACG) to get information about differences between APAC and CPAC.MethodsPatients with F-APAC and F-CPACG without prior treatment were enrolled from glaucoma clinics. Parameters were measured on ultrasound biomicroscopy images, including pupil diameter, lens vault (LV), anterior chamber depth, anterior chamber width, iris area, iris thickness (IT 750 and 2000), angle-opening distance (AOD 500 and 750), trabecular-iris space area (TISA 500 and 750), trabecular iris angle (TIA 500 and 750), trabecular–ciliary angle, and ciliary process area. Multivariate logistic regression analysis was performed to determine the most important parameters associated with F-APAC compared with F-CPACG.ResultsFifty-five patients with APAC and 55 patients with CPACG were examined. The anterior chamber depth, IT 750, AOD 750, trabecular iris angle 750, and trabecular–ciliary angle were smaller, and LV and ciliary process area were greater in F-APAC as compared with F-CPACG (P ≤ 0.01). Multivariate logistic regression showed that thinner IT 750, smaller AOD 750, and larger LV were significantly associated with F-APAC (P < 0.01). IT 750 (area under the curve, 0.703) performed relatively better than AOD 750 (area under the curve, 0.696) in distinguishing F-APAC from F-CPACG, with the best cutoff of 0.404 mm and 0.126 mm, respectively.ConclusionsCompared with F-CPACG, F-APAC had thinner peripheral iris, narrower anterior chamber angle, shallower anterior chamber depth, greater LV, larger and anteriorly positioned ciliary body. IT 750, AOD 750, and LV played important roles in distinguishing eyes predisposed to APAC or CPAC.