Prevalence Of Retinal Vein Occlusion Research Articles

Trends in the Prevalence of Common Retinal and Optic Nerve Diseases in China: An Artificial Intelligence Based National Screening.

Retinal and optic nerve diseases have become the primary cause of irreversible vision loss and blindness. However, there is still a lack of thorough evaluation regarding their prevalence in China. This artificial intelligence-based national screening study applied a previously developed deep learning algorithm, named the Retinal Artificial Intelligence Diagnosis System (RAIDS). De-identified personal medical records from January 2019 to December 2021 were extracted from 65 examination centers in 19 provinces of China. Crude prevalence and age-sex-adjusted prevalence were calculated by mapping to the standard population in the seventh national census. In 2021, adjusted referral possible glaucoma (63.29, 95% confidence interval [CI] = 57.12-68.90 cases per 1000), epiretinal macular membrane (21.84, 95% CI = 15.64-29.22), age-related macular degeneration (13.93, 95% CI = 11.09-17.17), and diabetic retinopathy (11.33, 95% CI = 8.89-13.77) ranked the highest among 10 diseases. Female participants had significantly higher adjusted prevalence of pathologic myopia, yet a lower adjusted prevalence of diabetic retinopathy, referral possible glaucoma, and hypertensive retinopathy than male participants. From 2019 to 2021, the adjusted prevalence of retinal vein occlusion (0.99, 95% CI = 0.73-1.26 to 1.88, 95% CI = 1.42-2.44), macular hole (0.59, 95% CI = 0.41-0.82 to 1.12, 95% CI = 0.76-1.51), and hypertensive retinopathy (0.53, 95% CI = 0.40-0.67 to 0.77, 95% CI = 0.60-0.95) significantly increased. The prevalence of diabetic retinopathy in participants under 50 years old significant increased. Retinal and optic nerve diseases are an important public health concern in China. Further well-conceived epidemiological studies are required to validate the observed increased prevalence of diabetic retinopathy, hypertensive retinopathy, retinal vein occlusion, and macular hole nationwide. This artificial intelligence system can be a potential tool to monitor the prevalence of major retinal and optic nerve diseases over a wide geographic area.

Prevalence and Associations of Peripheral Arterial Disease in China: The Beijing Eye Study

PurposeTo explore the prevalence and associations of peripheral arterial disease (PAD) in China DesignPopulation-based incidence estimate and cross-sectional study MethodsThe participants (n=3468) of the Beijing Eye Study underwent a detailed ophthalmological and systemic examination including assessment of the ankle-brachial index (ABI). PAD was defined by an ABI of less than 0.9. ResultsBlood pressure measurements of both arms and ankles were available for 1078 (31.1%) individuals. An ABI (mean:1.09±0.11;median:1.10;range:0.25,1.36) of <0.9 and <0.95 was found in 32/1078 participants (3.0%;95%CI:2.0,4.0) and 70/1078 individuals (6.5%;95%CI:5.0,8.0), respectively. Higher PAD prevalence (multivariable analysis) was associated with older age (odds ratio (OR):1.08;95%CI:1.02,1.15;P=0.009), lower level of education (OR:0.62;95%CI:0.43,0.90;P=0.01), lower quality of life (OR:0.67;95%CI:1.11,2.32), higher glucose serum concentration (OR:1.36;95%CI:1.09,1.58;P=0.006), lower estimated glomerular filtration rate (OR:0.98;95%CI:0.96,0.99;P=0.04), and higher prevalence of retinal vein occlusions (OR7.30;95%CI:1.63,32.6;P=0.009). PAD prevalence was not associated with the prevalence of glaucoma (P=0.53) (open-angle glaucoma:P=0.42; angle-closure glaucoma:P=0.57) and age-related macular degeneration (any AMD:P=0.39; early AMD:P=0.31; intermediate AMD:P=0.92; late AMD:P=0.99), prevalence (P=0.26) and stage (P=0.07) of diabetic retinopathy, prevalence (P=0.38) and degree (P=0.68) of nuclear cataract, prevalence (P=0.39) and degree (P=0.72) of cortical cataract, prevalence of subcapsular cataract (P=0.86), prevalence of pseudoexfoliation (P=0.65), intraocular pressure (P=0.50), axial length (P=0.56), and peripapillary retinal nerve fiber layer thickness (P=0.68). ConclusionsThe PAD prevalence (3.0%;95%CI:2.0,4.0) was relatively low in this cohort from rural and urban Beijing, with older age, lower educational level, lower quality of life, higher glucose serum concentration, lower estimated glomerular filtration rate, and higher prevalence of retinal vein occlusions as main associated factors.

Prevalence and risk factors of retinal vein occlusion in the United States: The National Health and Nutrition Examination Survey, 2005 to 2008

Retinal vein occlusion (RVO) is a rare, vision-threatening vascular disorder. Due to limited recovery associated with RVO, prevention is essential. There is a significant discrepancy in previously reported epidemiological studies in the United States on the prevalence and risk factors of RVO. The purpose of this retrospective, cross-sectional study was to determine the prevalence and risk factors of RVO in adults ≥40 years of age in the US using the National Health and Nutrition Examination Survey (NHANES) 2005–2008. We collected information on the demographic characteristics, medical conditions, and ocular pathology of NHANES participants. We performed weighted analysis to estimate national prevalence rates and multivariate analysis to examine associated risk factors. The main outcome measures were the prevalence of RVO and the odds ratios of associated risk factors. We included 5559 participants and found 33 cases of RVO. The overall prevalence of RVO in the US was 0.50%. Age, per 10-year increase (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.31–2.92) and elevated diastolic blood pressure, per 10 mm Hg increase (OR 1.47; 95% CI, 1.10–2.12) were significant risk factors for RVO. Race, sex, glaucoma, elevated cholesterol, and self-reported history of diabetes, stroke, and heart disease were not significant risk factors. RVO is significantly associated with older age and elevated diastolic blood pressure. Our findings should alert clinicians to identify individuals at risk for RVO.

Retinal vein occlusion in patients with diabetes mellitus in a tertiary care teaching hospital

Retinal vein occlusion is an important cause of vision loss. Diabetes mellitus, hypertension and dyslipidemia increase the risk for endothelial damage or abnormal blood flow and thus associated with retinal vein occlusion. To access the prevalence of retinal vein occlusion in diabetic patients and its association with systemic illness in a tertiary care teaching hospital, Gorakhpur.A descriptive, observational study was done on diabetic patients attending the eye OPD. Consent was taken and patient underwent direct and indirect ophthalmoscopy, optical coherence tomography and fundus fluorescein angiography. Medical history regarding duration of diabetes, hypertension, hyperlipidemia, cerebro-vascular accidents were obtained.The study included 846 patients with type II diabetes mellitus. In this study 6.6% (n=56) patients detected with RVO in which 34(61%) were male and 22 (39%) were female. The mean age was 58 years.78.5% (n=44) of them had BRVO and 21% (n=12) had CRVO. The frequency of unilateral BRVO (n=34, 81%) was more common than bilateral BRVO (n=10, 71%). The frequency of unilateral CRVO was 19% (n=8) and bilateral CRVO was 28.5% (n=4). The duration of diabetes and uncontrolled diabetes affects the occurrence of RVO.Macula involving BRVO was found in 59% (n=26) of patients, suggesting that diabetic patients with RVO has greater risk of severe vision loss due to macular involvement in BRVO.Diabetic patients with history of hypertension, hyperlipidemia, CVA were significantly associated with RVO (p&amp;#60; 0.0001).Patients with type II diabetes mellitus carries risk for development of RVO.

Prevalence of Retinal Vein Occlusions and Estimated Cerebrospinal Fluid Pressure: The Kailuan Eye Study.

PurposeTo investigate the prevalence of retinal vein occlusions (RVOs) and associated factors in a Chinese population.Patients and MethodsThe cross-sectional community-based Kailuan Eye Study included individuals who participated in the Kailuan Study. RVOs were diagnosed on the fundus photographs. Estimated cerebrospinal fluid pressure (eCSFP) was calculated as “eCSFP=0.44*Body Mass Index+0.16*Diastolic Blood Pressure-0.18*Age”.ResultsThe study included 12,499 participants with a mean age of 52.9±13.1 years. The overall prevalence of RVO was 120/12,499 or 0.96%, with branch RVOs observed in 116/12,499 individuals and central RVOs in 4/12,499 individuals. RVOs started at the optic disc in 19 participants (15.8% of all RVOs), and in 101 (84.2%) individuals arterio-venous crossings outside the optic disc. In multivariable analysis, a higher RVO prevalence was associated with older age (P<0.001), higher eCSFP (P<0.001), and higher fasting serum glucose concentration (P<0.001). Differentiating between RVOs at arterio-venous crossings and RVOs at the optic disc revealed that the prevalence of both RVO types was associated with higher eCSFP (P<0.001 and P=0.004, respectively) after adjusting for age and fasting serum glucose concentration.ConclusionIn this adult Chinese population recruited on a community basis, the prevalence of any RVO (mean: 0.96) was associated with older age, higher eCSFP and higher fasting serum glucose concentration. Higher eCSFP may play an etiologic role in RVOs.

POSTERIOR FUNDUS HEMORRHAGES: Frequency and Associated Factors: The Beijing Eye Study.

To examine frequency and associations of retinal hemorrhages. The population-based Beijing Eye Study included 3,468 individuals. Monoscopic fundus photographs were examined for hemorrhages. Retinal hemorrhages were detected in 515 eyes (429 individuals) (prevalence: 7.6%; 95% confidence interval [CI]: 7.0-8.0 per eye; 12.7%; 95% CI: 11.7-13.7 per person). Higher prevalence of retinal hemorrhages was correlated (multivariate analysis) with higher systolic blood pressure (P < 0.001; odds ratio: 1.02; 95% CI: 1.01-1.03), higher prevalence of diabetic retinopathy (P < 0.001; odds ratio: 121; 95% CI: 61-240), and higher prevalence of retinal vein occlusions (P < 0.001; odds ratio: 27; 95% CI: 17-42). Retinal hemorrhages were due to diabetic retinopathy (189 [36.7%] eyes), retinal vein occlusions (n = 65 [12.6%]), posterior vitreous detachment (n = 23 [4.5%]), glaucoma (n = 14 [2.7%]), exudative age-related macular degeneration (n = 8 [1.6%]), hypertensive retinopathy (n = 10 [1.9%]), and exudative myopic maculopathy (n = 1 [0.2%]). Retinal hemorrhages without evident ocular cause ("NOH") were detected in 204 (3.0%) eyes (or 39.6% of all retinal hemorrhages). Higher prevalence of NOHs was correlated with higher systolic blood pressure (P < 0.001; odds ratio: 1.02; 95% CI: 1.01-1.03) after adjusting for blood glucose concentration and prevalence of cortical cataract. In a population-based recruited cohort of individuals aged 50+ years, prevalence of any fundus hemorrhage was about 8% per eye and 13% per individual. Approximately 60% of the hemorrhages were due to ocular reasons, mainly diabetic retinopathy, retinal vein occlusions, and posterior vitreous detachment, whereas 40% of the bleedings were not evidently associated with ophthalmologic causes but strongly with elevated systolic blood pressure.

Genetic polymorphisms associated with the prevalence of retinal vein occlusion in a Greek population.

To investigate possible associations of single-nucleotide polymorphisms (SNPs) from five genes with branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). A total of 69 patients with retinal vein occlusion-RVO (24 with BRVO and 45 with CRVO), and 82 controls, were enrolled in this study. All subjects were screened for hypertension, diabetes mellitus, hyperlipidemia, glaucoma, anticoagulant medication, smoking status and history of stroke. The genotyping of AGTR1-A1166C, adiponectin + 276 G/T, MMP2-1306C/T, Gpla/lla-C807T/G873A and VKORC1-G1639A polymorphisms was performed using restriction fragment length polymorphism or allele-specific polymerase chain reaction. The percentage of the AGTR1-A1166C C allele carriers and Gpla/lla-C807T/G873A T/A carriers was significantly higher in the CRVO patients than in the controls (P = 0.00001 and P = 0.0004, respectively). At the multiple logistic regression analysis, the AGTR1-A1166C C allele carrier status and the Gpla/lla-C807T/G873A T/A allele carrier status were found to be associated with an increased risk of CRVO. Moreover, adiponectin + 276 G/T T allele carriers had a significantly increased risk of RVO in subjects ≥ 75years old. There was no significant difference between the BRVO patients and controls concerning the genotype or the allele frequency distributions of these SNPs. The genotype distributions or allelic frequencies of the other evaluated polymorphisms did not significantly differ between the patients with RVO and the control subjects. AGTR1 A1166C and Gpla/lla C807T/G873A polymorphisms are likely to be risk factors for CRVO. Adiponectin + 276 G/T SNP is likely to predispose to RVO in older subjects.

Epidemiology, Prevalence, and Incidence in Central Retinal Vein Occlusion and Macular Edema

Retinal vein occlusion (RVO) is one of the most common causes of acquired retinal vascular anomalies in adults and is a common cause of visual loss. There is little data on the prevalence of RVO in the general population, although it is at least as early as 1855 and there are more than 3000 publications. The number of studies on the incidence of RVO is relatively small. Reduced vision in patients affected by RVO can result from retinal ischemia and/or accumulation of fluid in the center of the retina (macular edema). In this review, studies on epidemiology, prevalence, and incidence in central retinal vein occlusion and macular edema were summarized and evaluated.

Prevalence of Retinal Vein Occlusion in Europe: A Systematic Review and Meta-Analysis

Purpose: The aim of this study was to examine the prevalence and incidence of retinal vein occlusions (RVO) in Europe. Methods: A systematic review and meta-analysis of the prevalence and incidence of RVO in Europe according to the Meta-Analyses of Observational Studies in Epidemiology (MOOSE) guidelines was performed in the databases PubMed, Embase and Web of Science. Based on Eurostat data, the total number of affected individuals in the EU was calculated and projected to the year 2050. Results: The random-effects pooled prevalence of RVO in Europe was 0.7% (95% CI: 0.5–0.9%) in persons aged 55 years and older based on the examination of 25,002 individuals from 4 prevalence studies. No European incidence studies were identified. The total number of affected individuals in the EU was estimated to rise by almost 20% from 900,000 today to 1.1 million in 2050. Conclusion: Published articles on the prevalence and incidence of RVO in Europe are limited. With the expected increase in affected persons, further epidemiological research is warranted for adequate healthcare planning.

Prevalence of retinal vein occlusion in the Australian National Eye Health Survey.

In Australia, knowledge of the epidemiology of retinal vein occlusion remains scarce because of a paucity of recent population-based data. The National Eye Health Survey (2015-2016) provides an up-to-date estimate of the prevalence of retinal vein occlusion in non-Indigenous and Indigenous Australian adults. To determine the prevalence and associations of retinal vein occlusion in a national sample of Indigenous and non-Indigenous Australian adults. Population-based cross-sectional study. A total of 3098 non-Indigenous Australians (aged 50-98years) and 1738 Indigenous Australians (aged 40-92years) living in 30 randomly selected sites, stratified by remoteness. Retinal vein occlusions were graded from retinal photographs using standardized protocols and recorded as central retinal vein occlusion or branch retinal vein occlusion. Prevalence of retinal vein occlusion. In the non-Indigenous population, the sampling weight adjusted prevalence of any retinal vein occlusion was 0.96% (95% confidence interval: 0.59, 1.6), with branch retinal vein occlusion observed in 0.72% (95% confidence interval: 0.41, 1.2) and central retinal vein occlusion in 0.24% (95% confidence interval: 0.13, 0.47). Any retinal vein occlusion was found in 0.91% (95% confidence interval: 0.47, 1.7) of Indigenous Australians aged 40years and over, with branch retinal vein occlusion observed in 0.83% (95% confidence interval: 0.40, 1.7) and central retinal vein occlusion in 0.07% (95% confidence interval: 0.02, 0.32). Older age (odds ratio=1.64 per 10years, P=0.006) and the presence of self-reported diabetes (odds ratio=3.24, P=0.006) were associated with any retinal vein occlusion after multivariable adjustments. Retinal vein occlusion was attributed as the cause of monocular vision loss (<6/12) in seven (0.25%) non-Indigenous and six (0.36%) Indigenous participants. These data suggest that retinal vein occlusion is relatively uncommon in the non-Indigenous Australians aged 50years and over and Indigenous Australians aged 40years and over. Similar to previous Australian and international reports, the prevalence of retinal vein occlusion rose sharply with age.

Retinal Vein Occlusion in a Multi-Ethnic Asian Population: The Singapore Epidemiology of Eye Disease Study

ABSTRACTPurpose: To describe the prevalence of retinal vein occlusion (RVO) and its risk factors in a multi-ethnic Asian population.Methods: This population-based study of 10,033 participants (75.7% response rate) included Chinese, Indian and Malay persons aged 40 years and older. A comprehensive ophthalmic examination, standardized interviews and laboratory blood tests were performed. Digital fundus photographs were assessed for presence of RVO following the definitions used in the Blue Mountains Eye Study. Regression analysis models were constructed to study the relationship between ocular and systemic factors and RVO. Age-specific prevalence rates of RVO were applied to project the number of people affected in Asia from 2013 to 2040.Results: The overall crude prevalence of RVO was 0.72% (n = 71; 95% confidence interval, CI, 0.54–0.87%). The crude prevalence of RVO was similar in Chinese, Indian and Malay participants (p = 0.865). In multivariable regression models, significant risk factors of RVO included increased age (odds ratio, OR, 1.03, 95% CI 1.01–1.06), hypertension (OR 3.65, 95% CI 1.61–8.31), increased serum creatinine (OR 1.04, 95% CI 1.01–1.06, per 10 mmol/L increase), history of heart attack (OR 2.25, 95% CI 1.11–4.54) and increased total cholesterol (OR 1.31, 95% CI 1.07–1.59, per 1 mmol/L increase). None of the ocular parameters were associated with RVO. RVO is estimated to affect up to 16 and 21 million people in Asia by 2020 and 2040, respectively.Conclusion: RVO was detected in 0.72% of a multi-ethnic Asian population aged 40–80 years in Singapore. The significant systemic risk factors of RVO are consistent with studies in white populations.

Changes in hemostasis-related parameters of blood and lacrimal fluid in patients with retinal vein occlusion

High prevalence of retinal vein occlusion in young people as well as treatment complexity and inadequate control of hemostatic parameters of blood and lacrimal fluid determine the significance of relevant research in patients with retinal vascular pathology. The data thus obtained may be useful for disease prognosis, severity evaluation and therapy control. This review is aimed to study hemostasis-related parameters of blood and lacrimal fluid in such patients.

Direct medical costs and resource use for treating central and branch retinal vein occlusion in commercially insured working-age and Medicare populations.

To quantify the burden of illness for incident branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO) in a commercially insured working-age (commercial) and Medicare US population. Retrospective cohort analysis of health care claims from 2003 through 2008 from commercial and Medicare patients with ≥2 outpatient diagnoses for BRVO or CRVO. The index date was the first retinal vein occlusion diagnosis. Patients with medical and pharmacy benefits were followed ≥1 year preindex and then between 1 year and 3 years postindex. Incidence and prevalence of retinal vein occlusion was determined. Burden of illness was compared with matched control subjects without retinal vein occlusion. The commercial sample comprised 1,188 CRVO and 2,252 BRVO cases, whereas the Medicare sample had 2,739 CRVO and 4,573 BRVO cases. Adjusted ratio of case-to-control, all-cause expenditures for commercial patients at 1 year and 3 years postindex were 1.88 and 1.68, respectively, for BRVO and 1.42 and 1.36, respectively, for CRVO. For Medicare patients, these were 1.29 and 1.13, respectively, for BRVO and 1.23 and 1.14, respectively, for CRVO. All comparisons were significant (P < 0.001). Health care utilization and expenditures for commercially insured working-age and Medicare patients with BRVO or CRVO were significantly greater than those for control subjects. Retinal vein occlusion development may be a marker for the increased severity of systemic vascular disease.

PREVALENCE AND ASSOCIATIONS OF RETINAL VEIN OCCLUSIONS

To determine the prevalence of retinal vein occlusions (RVOs) in rural central India. The population-based Central India Eye and Medical Study was performed in rural central India and included 4,711 subjects (30 years and older). Using fundus photographs, we assessed the prevalence of branch retinal vein occlusions and central retinal vein occlusions. An RVO was detected in 38 eyes (0.42 ± 0.07%; 95% confidence interval: 0.29-0.56) of 35 subjects (0.76 ± 0.13%; 95% confidence interval: 0.50-1.01). Prevalence of branch retinal vein occlusions was 0.66% ± 0.12% per subject (95% confidence interval: 0.42%-0.90%) and of central retinal vein occlusions was 0.11% ± 0.05% per subject (95% confidence interval: 0.01%-0.21%). In binary logistic analysis, presence of RVOs was associated with higher age (P = 0.007), systolic blood pressure (P < 0.001), blood concentration of urea (P = 0.02), and narrower anterior chamber angle (P < 0.03). The RVO prevalence was not significantly (all Ps > 0.10) associated with body mass index; blood concentrations of glucose, cholesterol, high-density lipoproteins, and creatinine; presence of diabetes mellitus, tuberculosis and malaria; nutritional parameters; alcohol consumption; refractive error; and optic disk size. The age-specific prevalence rates of RVOs were 0.18% ± 0.13%, 0.29% ± 0.15%, 0.89% ± 0.34%, 1.07% ± 0.36%, 2.72% ± 0.85%, and 3.64% ± 2.55%, respectively, for decadal age groups. In two (5%) eyes, RVO had caused low vision (visual acuity <20/60 and ≥20/400). In the rural agrarian low-income population of Central India, RVOs were detected in 0.8% of adults, with branch retinal vein occlusions being approximately seven times more common than central retinal vein occlusions. Main associated factors were higher age, blood pressure, urea blood concentration, and narrow chamber angle. RVOs were no major reason for visual impairment.

Impact of Arterial Hypertension on the Eye

Systemic hypertension has been linked to a wide range of major eye diseases. High arterial blood pressure (BP) decreases choroidal circulatory flow, increases intraocular pressure, and is associated with retinal microvascular abnormalities and prevalence of retinal vein occlusion (RVO) and retinopathy. This review offers a comprehensive overview of ocular diseases associated with hypertension and emphasizes their importance as predictors to future cardiovascular events. It also gives evidence-based clinical data for the therapeutic approach of eye disease in hypertensive patients.

Prevalence and Systemic Risk Factors for Retinal Vein Occlusion in a General Japanese Population: The Hisayama Study

To examine the prevalence of retinal vein occlusion (RVO) and its systemic relevant factors in a general Japanese population aged 40 years or older. In 1998, 1775 Hisayama residents consented to participate in the study. Each participant underwent a comprehensive examination that included ophthalmic testing. RVO was determined by grading color fundus photographs. Logistic regression analysis was performed to determine risk factors for RVO. Of the 1775 subjects examined, 38 had RVO. The prevalence of RVO was 2.1% (2.0% for branch RVO and 0.2% for central RVO). After adjustment for age and sex, it was found that systolic and diastolic blood pressures, hypertension, and hematocrit were significantly associated with RVO. In multivariate analysis, age (per 10 years; odds ratio [OR], 1.47; 95% confidence interval [CI], 1.04-2.08), hypertension (OR, 4.25; 95% CI, 1.82-9.94), and hematocrit (per 10%; OR, 3.09; 95% CI, 1.10-1.22) remained independently significant risk factors for RVO. Both high-normal blood pressure and hypertension were significantly associated with RVO. Furthermore, compared with normotensive subjects without high hematocrit, the likelihood of RVO was markedly high in subjects having both high blood pressure and high hematocrit (age- and sex-adjusted OR, 36.0; 95% CI, 4.43-292). The findings suggest that the prevalence of RVO is higher in the Japanese than in other Asians or Caucasians and that older age, higher hematocrit, and both hypertension and high-normal blood pressure are significant risk factors for RVO in the Japanese.

The Prevalence of Retinal Vein Occlusion: Pooled Data from Population Studies from the United States, Europe, Asia, and Australia

To summarize the prevalence of retinal vein occlusion (RVO) from studies in the United States, Europe, Asia, and Australia. Pooled analysis using individual population-based data. Individual participant data from population-based studies around the world that had ascertained RVO from fundus photographs. Each study provided data on branch RVO and central RVO by age, sex, and ethnicity. Prevalence rates were directly age and sex standardized to the 2008 world population aged 30 years and older. Estimates were calculated by study and, after pooling, by ethnicity. Summary estimates included studies in which RVO was assessed from fundus photographs on >or=2 fields of both eyes. Any RVO, CRVO, or BRVO. The combined pooled data contained 68,751 individuals from 15 studies, with participants' ages ranging from 30 to 101 years. In analyses of 11 studies that assessed >or=2 fundus fields of both eyes (n=49,869), the age- and sex-standardized prevalence was 5.20 per 1000 (confidence interval [CI], 4.40-5.99) for any RVO, 4.42 per 1000 (CI, 3.65-5.19) for BRVO, and 0.80 per 1000 (CI, 0.61-0.99) for CRVO. Prevalence varied by race/ethnicity and increased with age, but did not differ by gender. The age- and sex-standardized prevalence of any RVO was 3.7 per 1000 (CI, 2.8-4.6) in whites (5 studies), 3.9 per 1000 (CI, 1.8-6.0) in blacks (1 study), 5.7 per 1000 (CI, 4.5-6.8) in Asians (6 studies), and 6.9 per 1000 (CI, 5.7-8.3) in Hispanics (3 studies). Prevalence for CRVO was lower than BRVO in all ethnic populations. On the basis of these data, an estimated 16.4 million (CI, 13.9-18.9) adults are affected by RVO, with 2.5 million (CI, 1.9-3.1) affected by CRVO and 13.9 million (CI, 11.5-16.4) affected by BRVO. Study limitations include non-uniform sampling frames in identifying study participants and in acquisition and grading of RVO data. Our study provides summary data on the prevalence of RVO and suggests that approximately 16 million people may have this condition. Research on preventive and treatment strategies for this sight-threatening eye disease is needed.

Smoking and retinal vein occlusions. The Beijing Eye Study

Dear Editor, One of the most common ocular vascular diseases is retinal vein occlusion, the prevalence of which has been estimated to range from 0.3% to 1.6% in recent populationbased studies, such as the Blue Mountains Eye Study [1], the Beaver Dam Eye Study [2], a combined analysis of the Atherosclerosis Risk in Communities and Cardiovascular Health Studies [3], and the Singapore Malay Eye Study [4]. Considering that smoking is generally one of the major risk factors for vascular diseases, we addressed in our study whether smoking is associated with the prevalence of retinal vein occlusions. The Beijing Eye Study is a population-based study, which was first performed in 2001 and included 4,439 subjects (response rate: 83.4%) out of 5,324 subjects invited to participate, with an age of 40+ years. The study was repeated in 2006, with 3,251 subjects participating (response rate: 73.2%). The Medical Ethics Committee of the Beijing Tongren Hospital had approved the study protocol. The study has been described in detail recently [5]. Using fundus photographs (fundus camera: CR6-45NM, Canon Inc., USA), the prevalence of retinal vein occlusions was determined [5]. Recent retinal vein occlusions were characterized by the presence of retinal edema, optic disc hyperemia or edema, scattered superficial or deep hemorrhages, and venous dilatation. Old retinal vein occlusions were characterized by occluded and sheathed retinal veins. Additionally, we measured the systolic and diastolic blood pressure, and body height and body weight. Fasting blood samples were biochemically examined, and information was obtained about smoking habits. Glaucoma was defined by the appearance of the optic nerve head, as described in detail recently [5]. The study sample consisted of 3,214 subjects with a mean age of 55.3±10.0 years (range: 40–84 years) and a mean refractive error of −0.36±2.22 diopters (−20.1 diopters to +7.50 diopters). A retinal vein occlusion was detected in 37 subjects (1.2%). Out of the 3,214 subjects, 1,042 participants (32.4%) were current smokers (n=725; 16.3 % of the study population) or former smokers (n=317; 7.1% of the study population). In univariate analysis, prevalence of retinal vein occlusions was significantly associated with higher age (P<0.001), body mass index (P=0.001), mean arterial blood pressure (P=0.002), presence of glaucomatous optic nerve damage (P<0.001), and former smoking (P=0.002). In univariate analysis, retinal vein occlusions were not significantly associated with smoking as a whole group [P=0.16; odds ratio (OR): 1.60; 95% confidence interval (CI): 0.83, 3.07], nor with current smoking (P=0.43; OR: 0.66; 95% CI: 0.28, 1.59), level of education (P=0.15), gender (P=0.68), urban versus rural region (P=0.77), fasting blood levels of glucose Proprietary interest none

Major Eye Diseases and Risk Factors Associated with Systemic Hypertension in an Adult Chinese Population: The Beijing Eye Study

To assess the relationship of hypertension with major eye diseases and other ocular parameters. Population-based study. The Beijing Eye Study is a population-based study that included 4439 Chinese subjects examined at the baseline examination in 2001; there was a follow-up examination in 2006, in which 3251 subjects participated, of whom 3222 had blood pressure measurements. All participants underwent an ophthalmic examination, anthropometric measurements, and blood pressure measurement. Hypertension was defined as a systolic blood pressure >or=140 mmHg and/or diastolic blood pressure >or=90 mmHg, and/or self-reported current treatment for hypertension with antihypertensive medication. Blood pressure and ocular parameters, including intraocular pressure and prevalence of major ophthalmic diseases. Mean age of participants in the present study was 60.4+/-10.0 years. Hypertension was present in 1500 (46.6%) of the 3222 subjects who had their blood pressure measured. In multiple regression analysis, hypertension was associated with higher intraocular pressure (beta = 0.39; 95% confidence interval [CI], 0.12-0.66; P = 0.005), focal arteriolar narrowing (odds ratio [OR], 1.78; 95% CI, 1.34-2.36; P<0.001), arteriovenous nicking (OR, 1.50; 95% CI, 1.11-2.04; P = 0.009), generalized retinal arteriolar narrowing (OR, 1.65; 95% CI, 1.30-2.09; P<0.001), retinal vein occlusions (OR, 2.86; 95% CI, 1.21-6.80; P = 0.02), and diabetic retinopathy (OR, 1.90; 95% CI, 1.08-3.31; P = 0.02). Hypertension was not significantly associated with the prevalence of open-angle glaucoma (P = 0.19), angle-closure glaucoma (P = 0.15), age-related macular degeneration (AMD) (P = 0.73), nuclear cataract (P = 0.88), posterior subcapsular cataract (P = 0.30), cortical cataract (P = 0.10), or area of alpha zone (P = 0.05) or beta zone of parapapillary atrophy (P = 0.95). In Chinese persons, while controlling for other systemic parameters, hypertension was associated with increased intraocular pressure, retinal microvascular abnormalities, and prevalence of retinal vein occlusion and diabetic retinopathy. Hypertension was not associated significantly with AMD, age-related cataract, or glaucoma.

Major eye diseases and risk factors associated with systemic hypertension in an adult chinese population: the Beijing Eye Study

Abstract Purpose To assess the relationship of hypertension with major eye diseases and other ocular parameters. Methods The Beijing Eye Study is a population‐based study. Examination at baseline in 2001; follow‐up examination in 2006; 3222 subjects had blood pressure measurements.All participants underwent a thourough ophthalmic examination and blood pressure measurement. Hypertension was defined as a systolic blood pressure ≥140 mm Hg and/or a diastolic blood pressure ≥90 mm Hg, and/or self‐reported current treatment for hypertension with antihypertensive medication. Results Mean age of participants in the present study was 60.4±10.0 years. Hypertension was present in 1500 (46.6%) of the 3222 subjects who had their blood pressure measured. In multiple regression analysis, hypertension was associated with higher intraocular pressure (P = 0.005), arterio‐venous nicking (P = 0.009),retinal vein occlusions (P = 0.02), and diabetic retinopathy (P = 0.02). Hypertension was not significantly associated with the prevalence of open‐angle glaucoma (P = 0.19) or angle‐closure glaucoma (P = 0.15), age‐related macular degeneration (P = 0.73), nuclear cataract (P = 0.88), posterior subcapsular cataract (P = 0.30), cortical cataract (P = 0.10), or area of alpha zone (P=0.05) or beta zone of parapapillary atrophy (P = 0.95). Conclusion In Chinese persons, while controlling for other systemic parameters, hypertension was associated with increased intraocular pressure, retinal microvascular abnormalities, and prevalence of retinal vein occlusion and diabetic retinopathy. Hypertension was not associated significantly with age‐related macular degeneration, age‐related cataract, or glaucoma