Prevalence and risk factors for primary open-angle glaucoma in a rural northeast China population: a population-based survey in Bin County, Harbin

Purpose

To estimate the prevalence and associated risk factors of primary open-angle glaucoma (POAG) in a rural population in northeast China.

Methods

A population-based survey was conducted within Bin County, Harbin of northeast China. Glaucoma was diagnosed using International Society of Geographical and Epidemiological Ophthalmology criteria. All the subjects underwent a complete ophthalmic examination.

Results

A total of 4956 (86.0%) of 5762 subjects aged 40 years or older were examined. The mean intraocular pressure (IOP) of right eyes was 14.0 (95% confidence interval (CI), 13.9 to 14.1) mm Hg. The prevalence of POAG was 0.71% (35/4956, 95% CI, 0.47 to 0.93). In these POAG subjects, 17 (48.6%) had elevated IOP >21 mm Hg in either eye, 3 (8.8%) participants had been treated by laser trabeculoplasty or trabeculectomy and were known to have POAG. Vision impairment to varying degrees was present in 20 subjects (58.8%) with 1 subject blind in both eyes and 8 subjects blind in one eye. On multivariate analysis, age, family history of glaucoma, systemic hypertension, and IOP were regarded as significant independent risk factors.

Conclusions

POAG is a disease of serious consequence and of low diagnosis and treatment rates in rural northeast China. Age, family history of glaucoma, systemic hypertension, and IOP remain as significant independent risk factors for POAG.     

Prevalence and causes of visual impairment in a rural North‐east China adult population: a population‐based survey in Bin County,Harbin

Acta Ophthalmol. 2010: 88: 669–674

Abstract.

Purpose: To investigate the prevalence and causes of visual impairment in a rural population in north‐east China. Methods: A population‐based study was conducted within Bin County, Harbin of north‐east China. Low vision and blindness were defined using the World Health Organization categories of visual impairment. The prevalence of visual impairment was estimated, and causes were identified based on best‐corrected visual acuity (BCVA) as well as presenting visual acuity (VA). Results: Out of 5764 people, 4956 (86.01%) aged older than 40 participated in the study. The prevalence of visual impairment, low vision and blindness based on presenting VA was 9.6% (BCVA, 6.6%), 7.7% (BCVA, 4.9%) and 1.9% (BCVA, 1.7%), respectively. Taking the presenting VA, cataract (44%) was the most common cause for visual impairment followed by uncorrected refractive error (24%), treatable causes of visual impairment accounted for 68% of the total cases. Cataract (59%) and glaucoma (15%) were leading causes for blindness based on presenting VA. According to BCVA, cataract was the leading cause of visual impairment and blindness (58% and 60%, respectively), followed by glaucoma (17% and 15%, respectively). The prevalence of visual impairment was higher among women than men (p < 0.0001) and increasing with age (p < 0.0001) and decreasing with increasing education level (p = 0.0075). Conclusion: Visual impairment was a serious public health problem in this rural population, with most of it easily remedied. Results highlighted the need for visual impairment prevention programs to an increasing number of elderly people, with a special emphasis on female and those with little or no education.     

中国陕西省农村原发性开角型青光眼流行病学调查

目的：调查陕西省农村人群原发性开角型青光眼的患病率及相关影响因素。方法：2003—07／12，采用按比例随机整群抽样的方法在陕南、陕北及关中3个地区农村调查8500人，所有受检人员均进行标准问卷调查，包括询问青光眼确诊史、家族史、发作史及手术史，并进行了相关的眼科检查，包括视力、外眼、眼前节、眼底检查。≥50岁人群及怀疑有高眼压者对其应用压平式眼压计测量眼压。对可疑青光眼者进行进一步检查，包括复查眼压、前房角镜检查、视野检查。结果：8500人中共有6815人完成了青光眼的相关检查，受检率为80．18％。原发性开角型青光眼患者共有9例，年龄为38-80（平均62．0）岁，患病率为0．13％，≥30岁、≥40岁和≥50岁人群患病率分别为0．23％、0．28％和0．39％。可疑原发性开角型青光眼患者有12例（0．18％），年龄为35-77（平均54.7）岁，比原发性开角型青光眼患者平均年龄约小7岁。多因素logistic回归分析显示患病率随着年龄的增长而增加（P=0．023）。除年龄外，高度近视也是该人群开角型青光眼发生的危险因素。有青光眼确诊史的患者占22．22％，其中无1例接受过药物或手术治疗。66．67％（6例）原发性开角型青光眼患者存在不同程度的视力损伤，其中盲目占33．33％。结论：原发性开角型青光眼的患病率与国内其他报道相近，且随着年龄的增长而增加。绝大部分患者无青光眼确诊史，并且从未接受过任何相关治疗。     

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.     

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.     

Power prediction for one‐piece and three‐piece intraocular lens implantation after cataract surgery in patients with chronic angle‐closure glaucoma: a prospective,randomized clinical trial

Purpose: To assess the accuracy of intraocular lens (IOL) power prediction for cataract surgery in chronic angle‐closure glaucoma (CACG) patients with different IOLs’ implantation. Methods: This prospective randomized clinical trial included 45 eyes with CACG and 48 eyes with normal controls undergoing cataract surgery. In the CACG group, 23 eyes (51%) had three‐piece IOL implantation and 22 eyes (49%) had one‐piece IOL implantation. In the normal control group, 25 eyes (52%) had three‐piece IOL implantation and 23 eyes (48%) had one‐piece IOL implantation. Using the SRK/T formula, the mean difference between the predicted and actual postoperative spherical equivalent [mean absolute error (MAE)] was obtained and converted to natural logarithm (ln) for statistical analysis. The power of the implanted IOL was calculated to predict postoperative SE using three formulas: SRK II, Holladay II and Hoffer Q by post hoc analysis in each group. The predictive accuracy of each formula was analysed by comparing the lnMAE. Results: In the one‐piece IOL group, there was no difference in lnMAE between the CACG and normal control group (p = 0.314). In the three‐piece IOL group, the lnMAE of the CACG group was larger than that of the normal control group (p < 0.001). The lnMAEs calculated by the SRK/T formula were more accurate than the Holladay II (p = 0.045) and Hoffer Q (p = 0.042) formula in the CACG one‐piece IOL group. Conclusions: Implantation of one‐piece IOLs provides similar power prediction accuracy comparable to normal cataract patients; this result may be explained by the IOL haptic configuration or design.     

Risk factors for incident open‐angle glaucoma: a population‐based 20‐year follow‐up study

Purpose:  To study the effect of potential risk factors on the development of open‐angle glaucoma (OAG) in a population in which pseudoexfoliation (PEX) is a common finding. Methods: In 1984–1986, a population‐based survey of 760 people aged 65–74 years was conducted in the municipality of Tierp, Sweden. From 1988 to 2006, a follow‐up study of the 530 people with normal visual fields has been in progress. To increase the cohort, 273 ophthalmic outpatients were enroled. Reliable visual fields were available for 679 people, representing 6 126 person‐years at risk. A time‐weighted mean intraocular pressure (IOP) for all visits was calculated. Results: Sixty‐four subjects developed definite OAG, 29 of whom were exposed to PEX. Risk factors associated with OAG were higher age, a positive family history, increased IOP and PEX. The age‐standardized rate ratio (SRR) was 14.8 times (95% confidence interval [CI] 7.92–27.8) greater in subjects with mean IOP ≥20 mmHg than in those with mean IOP <20 mmHg. When subjects with IOP <20 mmHg at baseline were affected by PEX, the SRR increased 5.01‐fold (95% CI 1.97–12.8), compared with the unaffected group. However, when mean IOP at follow‐up was taken into account, there was no relationship between OAG and PEX as a distinct risk factor. Among participants in the population survey, 69% of all cases were attributable to a mean IOP ≥20 mmHg. Conclusion: Increased IOP and PEX were serious risk factors for incident OAG. The effect of PEX was mediated by increased IOP.     

Pseudoexfoliation and Alzheimer’s disease: a population‐based 30‐year follow‐up study

Purpose: To determine the effect of pseudoexfoliation (PEX) on the development of Alzheimer’s disease (AD) in a population in which PEX is a common finding. The relationship between open‐angle glaucoma (OAG) and AD was also studied. Methods: Predictors of incident AD, including mixed and unspecified dementia, were analysed in a cohort of 679 residents 65–74 years of age, examined in a population survey in the municipality of Tierp, Sweden, 1984–1986. To expand the cohort, participants in other studies in Tierp were enrolled. In this way, the cohort embraced 1123 people, representing more than 15 700 person‐years at risk. Medical records were reviewed to identify subjects diagnosed with dementia. Those with a follow‐up time shorter than 2 years were excluded from the study. Results: By the conclusion of the study, in December 2011, 174 new cases of AD, including mixed and unspecified dementia, had been detected, 41 of whom were affected by PEX at baseline. Higher age and female gender were the only predictors identified. No association between PEX and AD was found (hazard ratio 0.98; 95% confidence interval 0.69–1.40). Newly diagnosed OAG at baseline did not increase the risk (hazard ratio 1.09; 95% confidence interval 0.69–1.74). Conclusion: Pseudoexfoliation is not a predictor of AD. No association was found between OAG and AD.     

武强县小学生沙眼流行病学调查

目的调查河北省武强县小学生沙眼的患病率,并分析其危险因素。方法采用随机整群抽样调查方法,抽取武强县7所学校小学生共计1622例,其中男817例,女805例;年龄6～16岁,平均（11.91±2.24）岁。所有被调查对象均进行临床检查,沙眼诊断标准参照世界卫生组织（WTO）制定的沙眼分期标准;从临床诊断为沙眼的患者中,随机抽样进行结膜刮片,镜检法检查沙眼包涵体,利用酶联免疫学与聚合酶链反应（PCR）检测沙眼衣原体;同时选择正常小学生作为正常对照。结果被调查的1622例小学生中,临床诊断为沙眼的379例,患病率为23.4%[95%置信区间（CI）：25.5%～21.3%],其中滤泡性沙眼（TF）307例（81%）,浸润性沙眼（TI）72例（19%）。患病率男为20.9%,女为25.8%,两者比较差异有统计学意义（χ2=5.455,P=0.020）。各年龄组沙眼患病率比较,差异有统计学意义（χ2=9.972,P=0.019）。从379例临床诊断沙眼中随机抽样了168例及正常对照组42例进行结膜刮片检查,沙眼包涵体均为阴性,酶联免疫学检测阳性64例（38.1%）,PCR检测阳性109例（64.9%）。危险因素分析表明沙眼的发生与城郊区居住、性别、年龄有关。结论武强县小学生中仍有沙眼流行,主要以TF为主,需针对危险因素开展沙眼防治。     

Pseudoexfoliation as a risk factor for prevalent open‐angle glaucoma

Purpose: To estimate the risk of open‐angle glaucoma (OAG) associated with exposure to pseudoexfoliation (PEX) and increased intraocular pressure (IOP). Methods: In 1984?86, a cross‐sectional, population‐based survey was conducted in the municipality of Tierp, central Sweden. Its target population comprised 2429 residents aged 65–74 years. In addition to a sample of 760 people, patients previously diagnosed with glaucoma were examined. The prevalence of OAG in the target population was estimated from the prevalence in the sample and patients already diagnosed. A review of prevalent cases in 1984–86 was undertaken in 2006. Results: Definite OAG was established in 77 cases, corresponding to a prevalence of 5.3% (95% confidence interval [CI] 4.4–6.2). Of these, 23 represented newly detected cases. The prevalence of PEX was 17.2% (95% CI 14.6–19.9), calculated from 134 cases in the population sample. When adjusting for gender, PEX was associated with a 4.7‐fold (95% CI 2.2–9.4) increased risk of OAG. For clinical cases only, the risk was 16‐fold (95% CI 4.8–56) greater in subjects with PEX, compared with those without PEX. In individuals without a previous diagnosis of glaucoma, an IOP ≥ 20 mmHg was associated with a 9.7‐fold (95% CI 3.7–27) increased risk, but PEX alone was not a risk factor for OAG (adjusted odds ratio = 0.96). Conclusions: Pseudoexfoliation was associated with OAG only in people previously diagnosed with the disease. In cases detected in the population‐based survey, increased IOP was a serious risk factor.     

Prevalence and risk factors of pterygium: a systematic review and meta-analysis

The present study was conducted to determine the global prevalence and risk factors for pterygium. Three thousand two hundred fifty-five articles were identified, of which 68 articles with a total of 415,911 participants from 24 countries were included in the final analysis. The prevalence of pterygium in the total population was 12% (95% confidence interval [CI] 11–14%). The lowest and highest prevalence rates were, respectively, 3% (95% CI 0.0–9%) in the 10- to 20-year-age group and 19.5% (95% CI 14.3–24.8%) in those over 80 years. The prevalence was 13% (95% CI 11–15%) in men and 12% (95% CI 9–13%) in women. The odds ratio for men was 1.30 (95% CI 1.14–1.45). The lowest prevalence of pterygium was reported in a clinic-based study in Saudi Arabia (0.07%) and the highest prevalence was in China (53%). The odds were 1.24 (95% CI 1.11–1.36) for sunlight exposure over 5 hours, 0.84 (95% CI 0.74–0.94) for smoking, 1.45 (95% CI 1.33–1.57) for living in rural areas, 1.17 (95% CI 1.03–1.32) for alcohol consumption, 1.46 (95% CI 1.36–1.55) for outdoor occupations, and 0.47 (95% CI 0.19–0.57) for use of sunglasses. This is the second meta-analysis arriving at an estimate of 12% for the prevalence of pterygium. According to our results, pterygium risk factors fall in 3 categories: demographic, environmental, and lifestyle factors. Older age, male gender, outdoors occupation, and living in rural environments are the leading demographic risk factors for the development of pterygium. Exposure to sunlight is the most common environmental risk factor, and the results of this study provide a more exact and reliable value of the effect of sunlight exposure. The use of sunglasses and cigarette smoking are protective factors, and the significant effect of alcohol consumption is related to lifestyle factors.