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.     

Mechanism and Etiology of Primary Chronic Angle Closure Glaucoma

The ocular anatomic features, pupil-blocking force, status of angle synechiae closure and positivity of provocative tests were compared between the primary chronic angle closure glaucoma (PCACG) and primary a-cute angle closure glaucoma (PAACG) by using ultrasonic biometry, computerized anterior ocular segment image processing technique, gonioscopy and provocative tests. The studies showed that the anterior chamber depth of PAACG was shallower than that of PCACG; the pupil-blocking force of PAACG was stronger than that of PCACG; the status of angle synechiae closure of PCACG were mainly creeping synechiae closure; the positivity of mydriasis test was much higher (46. 01%) in PCACG than that (6. 8%) in PAACG after iridectomy. These facts suggest approximately half of the PCACG cases may be multi-mechanism to contribute to the angle closure besides the mechanism of pupillary block. Therefore, the authors emphasis that the pupillary block must be eliminated as well as the other mechanism for the treatment     

Progression of Primary Angle Closure Suspect to Primary Angle Closure and Associated Risk Factors: The Handan Eye Study

PurposeTo investigate the progression of angle closure from primary angle closure suspect (PACS) and associated risk factors over five years in rural Chinese adults.MethodsIn this population-based cohort study, subjects aged ≥30 years old with unilateral or bilateral PACS at baseline of the Handan Eye Study who participated in the follow-up and had undergone baseline and follow-up gonioscopic examinations were included. The progression of angle closure was defined as the presence of primary angle closure (PAC)/primary angle-closure glaucoma (PACG) during the follow-up in subjects with PACS at baseline. Ocular data from the right eye were used for cases with bilateral PACS and unilateral PACS in the right eye at baseline. For those with unilateral PACS in the left eye at baseline, ocular data from the left eye were used. Demographic information, ocular conditions, personal history, and systemic comorbidities were compared between the progression and nonprogression groups. Univariate and multivariate logistic regression was performed to identify the baseline risk factors for progression of angle closure.ResultsIn total, 526 subjects (111 male, 415 female) with baseline PACS were finally enrolled. The overall progression of PACS to angle closure was 32 cases (31 PAC, 1 PACG). Logistic regression analysis identified narrower mean angle width (P < 0.001) to be associated with the progression.ConclusionsWe report the progression from baseline PACS to PAC/PACG after five years. And baseline mean angle width was determined to be independent predictive risk factor for the progression of angle closure.     

原发性闭角型青光眼流行病学研究进展

青光眼是全球第二大致盲眼病、不可逆性盲最主要的原因。原发性闭角型青光眼(PACG)是亚洲、特别是东亚、中国人中最常见的青光眼类型。随着社会、经济、环境的变化以及诊疗手段的进步,青光眼的流行病学特点不断变化;不同的青光眼诊断标准和分类系统也会导致不同的流行病学调查结果;流行病学的特征又指导着临床干预措施;这一切都密切相关,因此,PACG流行病学状况对青光眼的防治有着重要的意义。本文就国内外PACG流行病学相关研究进展作一综述。     

Changes in Iris Stiffness and Permeability in Primary Angle Closure Glaucoma

PurposeTo evaluate the biomechanical properties of the iris by evaluating iris movement during pupil constriction and to compare such properties between healthy and primary angle-closure glaucoma (PACG) subjects.MethodsA total of 140 subjects were recruited for this study. In a dark room, the anterior segments of one eye per subject were scanned using anterior segment optical coherence tomography imaging during induced pupil constriction with an external white light source of 1700 lux. Using a custom segmentation code, we automatically isolated the iris segments from the AS-OCT images, which were then discretized and transformed into a three-dimensional point cloud. For each iris, a finite element (FE) mesh was constructed from the point cloud, and an inverse FE simulation was performed to match the clinically observed iris constriction in the AS-OCT images. Through this optimization process, we were able to identify the elastic modulus and permeability of each iris.ResultsFor all 140 subjects (95 healthy and 45 PACG of Indian/Chinese ethnicity; age 60.2 ± 8.7 for PACG subjects and 57.7 ± 10.1 for healthy subjects), the simulated deformation pattern of the iris during pupil constriction matched well with OCT images. We found that the iris stiffness was higher in PACG than in healthy controls (24.5 ± 8.4 kPa vs. 17.1 ± 6.6 kPa with 40 kPa of active stress specified in the sphincter region; P < 0.001), whereas iris permeability was lower (0.41 ± 0.2 mm²/kPa s vs. 0.55 ± 0.2 mm²/kPa s; p = 0.142).ConclusionsThis study suggests that the biomechanical properties of the iris in PACG are different from those in healthy controls. An improved understanding of the biomechanical behavior of the iris may have implications for the understanding and management of angle-closure glaucoma.     

急性原发性闭角型青光眼不同病程视野损害特点及影响因素

目的：探讨急性原发性闭角型青光眼（APACG）不同病程视野损害的特点及其影响因素。方法：病例对照研究。连续收集2015年9月至2016年9月于中山大学中山眼科中心确诊为APACG的患者。根据临床特征将患眼分为临床前期组、药物缓解期组、慢性期组,根据APACG急性发作持续时间将药物缓解期组及慢性期组患者分为急性发作持续时间7 d以内组及7 d以上组。选择同期在门诊体检者中年龄、性别相匹配的健康成年人作为正常对照组。记录所有对象临床特征,使用Humphrey 750型视野分析仪30-2 SITA-Standard标准阈值程序进行视野检查。比较各组间临床特征和视野检查结果,并分析眼压、杯盘比（C/D）、房角粘闭范围、急性发作时最高眼压、急性发作持续时间与视野平均偏差（MD）、视野指数（VFI）、模式标准差（PSD）等的相关性。采用卡方检验、独立样本t检验、方差分析、秩和检验及Spearman相关分析进行数据分析。结果：共纳入正常对照组20例（20眼）,APACG患者74例（74眼）,其中临床前期组24例,药物缓解期组28例,慢性期组22例。4组间VFI值和MD值总体差异有统计学意义（F=60.588、61.018,P < 0.001）,组间两两比较发现慢性期组MD值和VFI值显著小于其他3组（P < 0.008）,药物缓解期组MD值和VFI值显著小于正常对照组（P < 0.008）。4 组间PSD值总体差异有统计学意义（F=60.022,P < 0.001）,组间两两比较发现慢性期组的PSD值均显著大于其他3组（P < 0.008）,临床前期组和药物缓解期组PSD值均显著大于正常对照组（P < 0.008）。药物缓解期组MD值、VFI值与急性发作持续时间均呈中度负相关（r=-0.653,P < 0.001;r=-0.547,P=0.003）,PSD值与急性发作持续时间呈中度正相关（r=0.579,P=0.001）;慢性期组MD值、VFI值与急性发作持续时间呈中度负相关（r=-0.441,P=0.044;r=-0.531,P=0.011）,与C/D呈中度负相关（r=-0.632,P=0.002;r=-0.633,P=0.002）。药物缓解期组急性发作持续时间7 d以内者的MD值和VFI值均大于急性发作持续时间7 d以上者（Z=-2.998,P=0.003;Z=-2.639,P=0.008）。结论：APACG急性发作后,药物缓解期组和慢性期组存在视野损害,且慢性期组视野损害较重。视野损害主要与急性发作持续时间有关。     

An Overview of Treatment Methods for Primary Angle Closure

ABSTRACT

Background: Glaucoma is the second leading cause of blindness in the world. Angle closure glaucoma accounts for 25% of all glaucoma, with Asia having the highest rate. Angle closure is an anatomical variation, making the Inuit, Chinese, and other Asians more susceptible. Current treatments include medical, laser, and surgical modalities.Purpose: To identify the current treatment protocols for primary angle closure. Discussion: The current general protocol to treat angle closure is to lower the intraocular pressure with medications and perform laser iridotomy. However, cataract surgery, laser iridoplasty, goniosynechiolysis, diode cyclophotocoagulation, and filtering surgery are additional treatment modalities used for primary angle closure. Conclusion: Primary angle closure occurs due to various anatomical angle variations. Laser iridotomy is not the sole method of treatment. Specifically, cataract surgery can be particularly effective in the treatment and prevention of angle closure. Recalcitrant cases can be treated with trabeculectomy and shunt implants, although these are not usually first-line treatments.     

Studies of Primary Angle Qosure Glaucoma in China

The resent researches on primary angle closure glaucoma (PACG) in China were reviewed. The prevalence of PACG (0.41%) in chinese is between the Caucasian and Eskimos, and chronic type is the dominant type in PACG. However, with the economic development and medical care improvements, the prevalence condition of PACG may change; several researches discovered that the mechanism of PACG, especially the chronic type, is not only because of pupil-blocking but also closely related to the mechanism of crowding of peripheral iris and the anterior location of the ciliary body. We supposed that PACG can be divided into several subtypes based on this machnism. Also, we believe that the use of ultrasound biomicroscopy (UBM) and ophthalmic laser in China has promoted the research of PACG and improved the level of prevention and treatment of PACG. Eye Science 1997; 13 : 120- 124.     

原发慢性闭角青光眼房水动力学改变与房角关闭范围,眼压及视功能损害的关系

对40例57眼原发性慢性闭角型青光眼(PCACG)和正常对照组30例60眼,进行了房水荧光素浓度曲线的测定。结果显示,PCACG房角关闭≥:180°组,房水荧光素下降率比对照组减少30.21%,所致视功能损害为青光眼早期和中期改变。而房角关闭≥270°组,房水荧光素下降率比对照组减少58.95%,所致视功能损害主要是青光眼晚期改变。证明PCACG房角关闭范围越大,房水荧光素下降率越低,眼压越高,视功能损害也就越严重。     

Combined Phacoemulsification, Intraocular Lens Implantation and Trabeculectomy for Chronic Angle Closure Glaucoma

Purpose: To investigate the results of combined phacoemulsification, intraocular lens implantation and trabeculectomy in Asian patients with chronic angle closure glaucoma (CACG). Methods: This was a retrospective non-comparative case series of 55 consecutive patients (57 eyes) who underwent phacoemulsification, posterior chamber intraocular lens implantation and trabeculectomy for CACG at the Singapore National Eye Centre between 1997–1998. The surgical outcome was assessed in terms of intraocular pressure (IOP), the incidence of complications and the visual acuity at last follow-up. Success was defined as final IOP 21 mmHg without medication and qualified success as final IOP 21 mmHg with medication. Patients with final IOP > 21 mmHg who required further glaucoma surgery, lost light perception or became pthisical, were classified as failures. The eyes were further categorized into two groups according to whether single-site or separate-sitesurgery was performed. The outcome was also compared among eyes in which per-operative antimetabolites were applied to the trabeculectomy site and those without antimetabolites. Results: The mean follow up was 22.0 ± 5.6 months (mean ± SD). Success was achieved in 46 (81%) eyes, qualified success in 10 (17%) eyes, and failure in 1 (2%) eye. In terms of IOP outcome, the success rate was similar in the two surgical groups (single-site or separate-site).There was no significant difference in IOP outcome among eyes in which per-operative antimetabolites were used and eyes with no per-operativeantimetabolites use. Forty-one eyes (72%) had 6/12 or better vision. There were no cases of intraoperative complications and the incidence of postoperative complications was low. Conclusions: Combined phacoemulsification, intraocular lens implantation and trabeculectomy is associated with good intraocular pressure control and visual outcome in patients with CACG.     

A 7-Year Population Study of Primary Angle Closure Glaucoma Admissions and Climate in Taiwan

Purpose: Using data from seven years of hospital admissions in Taiwan, this study sets out to investigate meteorological factors associated with primary angle closure glaucoma (PACG). We investigated the relationship between PACG admissions and five different climate indices. Method: Hospital admissions data from the Taiwan National Health Insurance Research Database (1997 to 2003) provided monthly PACG admission rates (per 100,000 population). We categorized the 4,722 PACG cases by gender and age (including four subgroups: 40–49, 50–59, 60–69, and ≥ 70 years). After adjusting for the time-trend effect, the Auto-Regressive Integrated Moving Average regression method was performed to evaluate the effects of climatic and monthly factors on PACG admission rates. Results: The mean annual rate of PACG admissions across the entire study period was 9.48/100,000 and higher in females than males (11.28 vs. 7.80/100,000). The PACG admissions were significantly higher in March for male patients, and for the 60 to 69-year-old and > 69-year-old age groups (p < 0.05). After adjustment for seasonality, month, and time-trend, a significant association between relative humidity and monthly PACG admission rates was observed for the total data set, for males, and for the 60- to 69-year-old (p < 0.05) populations. No such relationship existed with temperature, rainfall, barometric pressure or hours of sunshine. Conclusion: This is the largest, nationwide, population-based study to investigate the dependence of PACG admission rates on meteorological conditions. PACG admission rates were significantly higher in March and with increased relative humidity. We recommend data be collected from other regions and from other ethnic groups to determine the general pattern worldwide.     

Primary Angle Closure Glaucoma in East Asia: Educational Attainment as a Protective Factor

Purpose: To examine the relationship between education, other risk factors and incident primary angle closure glaucoma (PACG).

Method: Glaucoma was excluded in a group of 4597 Mongolian volunteers in 1999. After 6 years, 1892 traced participants had full ophthalmic examination, dilated disc photographs and agreed to complete a questionnaire on socio-economic status. PACG was diagnosed using both structural and functional evidence from objective grading of paired disc photographs, follow up visual fields and clinical examination. Ophthalmic examination included van Herick grading, Goldmann intraocular pressure (IOP), gonioscopy, lens opacity grading and dilated disc examination. Central anterior chamber depth, lens thickness and axial length were recorded using ultrasound A scan mounted on a slitlamp. Education level was assessed using national census categories.

Results: PACG was diagnosed in 29 participants (6 year incidence?=?1.53%, 95% confidence interval (CI)?=?1.03–2.19%). In univariate analysis, risk factors for incident PACG included presence of refractive error, narrow van Herick grading of ≤15%, narrower average Shaffer grading, higher IOP, larger cup disc ratio and lower levels of education. In multivariate analysis, adjusted for age, sex, Shaffer grading, refractive error and IOP, those with no formal education were approximately 7 times more likely to develop PACG compared to those with >8 years of formal schooling (OR?=?7.27, 95% CI?=?2.73–19.38).

Conclusions: People with lower levels of education have a higher risk of incident PACG, independent of age, sex, IOP and axial length.     

Association of SOD2 Mutation (c.47T > C) with Various Primary Angle Closure Glaucoma Clinical Indices

We investigated whether the c.47T?>?C polymorphism (SNP rs4880) in the manganese superoxide dismutase (SOD2) gene is a risk factor for primary angle closure glaucoma (PACG) in the Saudi population. Among cases (n?=?139), the prevalence of various genotypes were 25.9%, 46.8% and 27.3% for T/T, C/T and C/C genotypes respectively. This trend was similar in the controls (n?=?403); 22.6%, 50.1% and 27.3% for T/T, C/T and C/C respectively. The differences in genotype distribution were not statistically significant (p?=?0.391 and 0.682 respectively). The minor allele frequency was 50.7% in cases and 52.4% in controls; this difference was not statistically significant (p?=?0.676). Investigating the potential association between this SOD2 polymorphism and different clinical indices, there was a statistically significant difference among different genotype groups in terms of three important clinical indices for PACG; Mean age at onset, duration of onset to and the mean LogMAR visual acuity (p?=?0.041, 0.018 and 0.033 respectively). The three markers are highly associated prognostic factors to diseases severity. If our results are proven in larger cohort and in various populations, then this SNP may have potentiality to be used as an indicator for PACG severity.     

GCIPL厚度测量在慢性闭角型青光眼诊断中的应用

目的：探讨高分辨率光学相干断层扫描（Cirrus HD OCT）测量黄斑区神经节细胞-内丛状层（GCIPL）厚度参数在慢性闭角型青光眼（CACG）中的诊断价值。方法：描述性研究。收集2014 年12 月至2016 年3 月在长沙爱尔眼科医院就诊的CACG患者66 例（76 眼）作为CACG组,根据Hodapp-Anderson-Parris分期方法,将CACG患者分为早期组（37 眼）、中期组（10 眼）和晚期组（29眼）。另选择与CACG组匹配的正常志愿者30 例（30 眼）作为正常对照组。所有研究对象分别进行Cirrus HD OCT检查与视野检查,测量黄斑区及其各分区域的GCIPL厚度。采用方差分析比较4 组患者各区GCIPL参数差异,采用Pearson相关分析对GCIPL厚度与平均视野缺损的相关性进行分析。结果：正常对照组及早、中、晚期组平均GCIPL分别为（85±14）μm、 （84±9）μm、 （72±21）μm、 （62± 15）μm,4 组间差异有统计学意义（F =15.89,P ＜0.001）,进一步两两比较发现,正常对照组与早期组之间差异无统计学意义（P =0.120）,与中、晚期组之间差异均有统计学意义（P ＜0.001）。CACG组平均GCIPL厚度与平均视野缺损呈正相关（r =0.636,P ＜0.001）。结论：GCIPL厚度参数对中晚期CACG的诊断具有临床价值,联合视野检查可以作为CACG的诊断分期及随访的重要参考指标。     

Diagnostic Accuracy of Van Herick Technique to Detect Pre-Disease States of Primary Angle Closure Glaucoma in a Resource Constraint Region

Objectives: To critically evaluate diagnostic accuracy of the van Herick (vH) technique in detection of gonioscopically occludable angle in a rural population and to explore ways to improve accuracy of the technique

Methods: The study cohort was formed by two-stage cluster random sampling. Peripheral anterior chamber depth grading was performed, using both traditional and modified (photographic comparison) vH techniques, under dark adapted and standard lighting conditions by a comprehensive ophthalmologist masked to the clinical features. The cut-off criterion for vH test was 25% of peripheral corneal thickness. The reference standard was dark room 4-mirror indentation gonioscopy performed by an experienced glaucoma specialist. This study adhered to the STARD guidelines for reporting diagnostic accuracy studies.

Results: We studied 111 eyes of 111 participants. The median age was 62 years. The angle was occludable by gonioscopy in 69 (62%) eyes; 58 eyes were primary angle closure suspects and 11 were primary angle closure patients. The likelihood ratio (95% confidence interval (CI)) of the positive (LR+) and negative (LR?) result by the traditional vH technique was 5.17 (2.43, 11) and 0.30 (0.20, 0.46), respectively. The LR+ by reducing and LR? by elevating the cut-off grade of the traditional vH technique were 9.4 (2.3, 37.4) and 0.08 (0.02, 0.31), respectively. The area under receiver operating characteristic curve did not differ significantly by photographic comparison or lighting condition (p = 0.13).

Conclusions: vH grading can be considered as a triage test before gonioscopy. The value of the vH technique to the diagnostic strategy is discussed.     

A Case of Invasive Aspergillosis Presenting as Acute Angle Closure Glaucoma

Purpose: To report a case of invasive aspergillosis presenting as acute angle closure glaucoma.Case: A 72-year-old male patient visited our clinic with decreased visual acuity and ocular pain on the right eye lasting for 3 d. His intraocular pressure was 42 mmHg in the right eye and 18 mmHg in the left eye. And, there was about 2 mm of exophthalmos, slight ptosis with decreased motility in all directions, conjunctival injection, moderate mydriasis with a relative afferent pupillary defect, and angle closure in the right eye. Orbital computed tomography and magenetic resonance imaging showed isotense mass involving right orbit and ethmoid sinus. Based on the biopsy, invasive aspergillosis was definitely diagnosed. Despite perfoming peripheral laser iridotomy and administrating antifungal agent and antiglaucoma medication, the patient was blinded in his right eye. During the follow-up period, visual acuity in the left eye suddenly decreased due to the invasive aspergillosis in the left paranasal sinus and optic nerve, and eventually the patient lost his left vision as well.Conclusion: This report is regarding a case of an invasive aspergillosis resulting in blindness in both eyes with the clinical manifestations of acute angle closure caused by invasive aspergillosis.     

Ultrasonic Evaluation of the Lens Thickness to Axial Length Factor in Primary Closure Angle Glaucoma

Ultrasonic biometry was done in 232 normal eyes and 138 eyes with primary angle closure glaucoma (ACG), using Ultrascan Digital B System IV (10 MHz). The ratio between the lens thickness and the axial length (lens thickness to axial length factor, LAF) was evaluated as a biometric index for assessing the eye with primary ACG in Chinese. LAF of 2.00 was found to be ideal point of demarcation between ACG and normal eyes (i.e., lens thickness equals to 1/5 of axial length). It appears that LAF is helpful in screening primary ACG eyes from eyes of the general population. This is similar to the anterior chamber depth of 2.5 mm which is recognized as a threshold for the occurrence of primary angle closure glaucoma.     

Management of Different Subtypes of Primary Angle Closure with Phacoemulsification and Viscogoniosynechialysis

Purpose: To retrospectively assess the effectiveness of combined phacoemulsification with viscogoniosynechialysis for patients with different subtypes of primary angle closure (PAC). Methods: Forty-three eyes of 37 patients diagnosed with PAC (12 eyes), PAC with glaucoma (PACG, 20 eyes), and acute PAC (11 eyes) were treated with phacoemulsification and viscogoniosynechialysis between November 2010 and October 2012. Main outcome measures were anterior chamber depth (ACD), intraocular pressure (IOP), the number of IOP-lowering medication, extent of peripheral anterior synechia (PAS), and visual acuity preoperatively and one month postoperatively. Results: All operations were successfully accomplished and no intra-operative complications were observed. The ACD, IOP, PAS, and visual acuity were all significantly improved postoperatively, especially in the acute PAC group, which resulted in few glaucoma drugs being needed. The IOP was decreased into equal or less than 21 mmHg in most patients postoperatively, except four patients had IOP slightly higher than 21 mmHg. However, they were restored to normal spontaneously or by medication at last follow-up. The extent of PAS was all reduced to less than 90 or 180°, with the visual acuity restored to more than 0.1. Conclusions: Combined phacoemulsification with viscogoniosynechialysis seems to be an effective surgical procedure in the treatment of various subtypes of PAC.     

原发性前房角关闭疾病的分类与演变

原发性前房角关闭疾病的分类较为繁杂.传统分类以症状学为依据,较系统地演绎了其临床发展过程,但对于青光眼概念的界定不够清晰.国际地域性和眼科流行病学研究组(ISGEO)的分类系统而简洁,比较适合流行病学调查,但不能完全适用于临床.最近有学者将各种临床亚型和发病机制结合起来进行分类,即分为可疑原发性前房角关闭、原发性前房角关闭Ⅰ级、Ⅱ级、Ⅲ级等,有利于指导治疗.