Ya Xing Wang

Subfoveal choroidal thickness: the Beijing Eye Study.

PURPOSE To study subfoveal choroidal thickness (SFCT) in adult Chinese subjects and its correlation with ocular biometric parameters, refractive error, and age. DESIGN Population-based longitudinal study. PARTICIPANTS The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6±9.8 years (range, 50-93 years). METHODS A detailed ophthalmic examination was performed, including spectral-domain optical coherence tomography (SD-OCT) with enhanced depth imaging for measurement of SFCT. MAIN OUTCOME MEASURES Subfoveal choroidal thickness. RESULTS The SFCT measurements were available for 3233 subjects (93.2%). Mean SFCT was 253.8±107.4 μm (range, 8-854 μm). In multivariate analysis, SFCT increased with younger age (P<0.001; correlation coefficient r=4.12; beta coefficient=0.37), shorter axial length (P<0.001; r=44.7; beta coefficient=0.46), male gender (P<0.001; r=28.5; beta coefficient=-0.13), deeper anterior chamber depth (P<0.001; r=39.3; beta coefficient=0.13), thicker lens (P<0.001; r=26.8; beta coefficient=0.08), flatter cornea (P<0.001; r=46.0; beta coefficient=0.11), and better best-corrected visual acuity (BCVA) (logarithm of minimal angle of resolution; P=0.001; r=48.4; beta coefficient=0.06). In multivariate analysis, SFCT was not significantly associated with blood pressure, ocular perfusion pressure, intraocular pressure, cigarette smoking, alcohol consumption, serum concentrations of lipids and glucose, diabetes mellitus, and arterial hypertension. In the myopic refractive error range of more than -1 diopter (D), SFCT decreased by 15 μm (95% confidence interval [CI], 11.9-18.5) for every increase in myopic refractive error of 1 D, or by 32 μm (95% CI, 37.1-26.0) for every increase in axial length of 1 mm. For each year increase in age, the SFCT decreased by 4.1 μm (95% CI, 4.6-3.7) (multivariate analysis). CONCLUSIONS Subfoveal choroidal thickness with a mean of 254±107 μm in elderly subjects with a mean age of 65 years decreased with age (4 μm per year of age) and myopia (15 μm per diopter [D] of myopia). It was also associated with male gender and the ocular biometric parameters of a deeper anterior chamber and thicker lens. The association between SFCT and BCVA indicates a functional aspect of SFCT. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Anterior Chamber Depth and Chamber Angle and Their Associations with Ocular and General Parameters: The Beijing Eye Study

PURPOSE To investigate the normative data of anterior chamber depth (ACD) and angle width and their associations in Chinese adults. DESIGN Population-based study. METHODS The Beijing Eye Study 2006 included 3,251 subjects (73.3%) (aged 45+ years) out of 4,439 subjects who participated in the 2001 survey and who returned for reexamination. The subjects underwent an ophthalmologic examination including measurement of the anterior chamber dimensions by slit-lamp-based optical coherence tomography (OCT). RESULTS Out of the 3,251 subjects, OCT measurements were available for 2,985 subjects (91.8%). Mean ACD measured 2.42 +/- 0.34 mm and the mean anterior chamber angle (ACA) was 38.3 +/- 16.3 degrees. In multivariate analysis, a shallow chamber depth was significantly associated with age (P < .001), hyperopic refractive error (P < .001), female gender (P < .001), short body stature (P = .003), nuclear cataract (P = .03), central corneal thickness [CCT] (P < .001), large optic disk (P < .001), and presence of chronic angle-closure glaucoma (P < .001). Correspondingly, a narrow ACA was associated with age (P < .001), female gender (P < .001), hyperopia (P < .001), nuclear cataract (P < .001), short body stature (P = .001), large optic disk (P < .001), and angle-closure glaucoma (P < .001). Chamber depth and angle width were not associated with presence of age-related maculopathy and diabetic retinopathy. CONCLUSIONS A shallow anterior chamber and a narrow chamber angle in Chinese adults are associated with age, female gender, hyperopia, nuclear cataract, small optic disk, short body stature, CCT, and chronic angle-closure glaucoma. These data may be helpful to explain anatomic relationships of the anterior segment of the eye, and to elucidate risk factors of angle-closure glaucoma.

Prevalence of Glaucoma in North China: The Beijing Eye Study

PURPOSE To assess the prevalence of glaucoma in adult Chinese. DESIGN Population-based study. METHODS The Beijing Eye Study in 2001 included 4439 subjects with an age of 40+ years. Glaucoma was determined using the ISGEO (International Society of Geographical and Epidemiological Ophthalmology) classification scheme. RESULTS Glaucoma was detected in 158 subjects (3.7%, 95% confidence interval [CI] 3.1%-4.2%), in which open-angle glaucoma (OAG), primary angle-closure glaucoma (PACG), and secondary glaucoma (SG) accounted for 2.6% (95% CI 2.1%-3.0%), 1.0% (95% CI 0.7%-1.3%), and 0.07% (95% CI 0%-0.1%), respectively. The overall glaucoma prevalence for the age groups of 40 to 49 years, 50 to 59 years, 60 to 69 years, and 70+ years was 2.2%, 2.5%, 4.4%, and 9.5%, respectively. Glaucoma prevalence increased significantly with age (P = .001), myopic refractive error (P < .001), and intraocular pressure (P < .001). The age-standardized prevalence of OAG, PACG, and SG was 2.5%, 1.0%, and 0.1%, respectively. Prevalence of glaucoma-related bilateral blindness or unilateral blindness was significantly (P = .02 and P = .03) higher in PACG than in OAG. Frequency of glaucoma-associated blindness and low vision was significantly higher in the rural area than in the urban region (6/62 vs 2/96, P = .04). CONCLUSIONS In the adult population of Greater Beijing, glaucoma prevalence was 3.6% and increased with age, myopic refractive error, and intraocular pressure. Glaucoma prevalence of 3.6% was comparable with figures from Caucasian populations. The ratio of OAG to PACG of 2.6:1 agrees with recent other studies from East Asia. Glaucoma-related blindness and low vision occurred significantly more often in PACG than in OAG.

Genome-wide analysis of multi-ancestry cohorts identifies new loci influencing intraocular pressure and susceptibility to glaucoma

Elevated intraocular pressure (IOP) is an important risk factor in developing glaucoma, and variability in IOP might herald glaucomatous development or progression. We report the results of a genome-wide association study meta-analysis of 18 population cohorts from the International Glaucoma Genetics Consortium (IGGC), comprising 35,296 multi-ancestry participants for IOP. We confirm genetic association of known loci for IOP and primary open-angle glaucoma (POAG) and identify four new IOP-associated loci located on chromosome 3q25.31 within the FNDC3B gene (P = 4.19 × 10−8 for rs6445055), two on chromosome 9 (P = 2.80 × 10−11 for rs2472493 near ABCA1 and P = 6.39 × 10−11 for rs8176693 within ABO) and one on chromosome 11p11.2 (best P = 1.04 × 10−11 for rs747782). Separate meta-analyses of 4 independent POAG cohorts, totaling 4,284 cases and 95,560 controls, showed that 3 of these loci for IOP were also associated with POAG.

Subfoveal Choroidal Thickness in Diabetes and Diabetic Retinopathy

PURPOSE To examine subfoveal choroidal thickness (SFCT) in patients with diabetes mellitus and patients with diabetic retinopathy. DESIGN Population-based, cross-sectional study. PARTICIPANTS The population-based Beijing Eye Study 2011 included 3468 individuals with a mean age of 64.6 ± 9.8 years (range, 50-93 years). METHODS A detailed ophthalmic examination was performed including spectral-domain optical coherence tomography (OCT) with enhanced depth imaging for measurement of SFCT and fundus photography for the assessment of diabetic retinopathy. MAIN OUTCOME MEASURES Subfoveal choroidal thickness. RESULTS Fasting blood samples, fundus photographs, and choroidal OCT images were available for 2041 subjects (58.8%), with 246 subjects (12.1 ± 0.7%) fulfilling the diagnosis of diabetes mellitus and 23 subjects having diabetic retinopathy. Mean SFCT did not differ significantly between patients with diabetes mellitus and nondiabetic subjects (266 ± 108 vs. 261 ± 103 μm; P=0.43) nor between patients with diabetic retinopathy and subjects without retinopathy (249 ± 86 vs. 262 ± 104 μm; P = 0.56). After adjustment for age, sex, axial length, lens thickness, anterior chamber depth, corneal curvature radius, and best-corrected visual acuity, SFCT was associated with a higher glycosylated hemoglobin (HbA1c) value (P<0.001; regression coefficient B, 8.18; 95% confidence interval [CI], 4.02-12.3); standardized coefficient β, 0.08) or with the presence of diabetes mellitus (P = 0.001; B, 21.3; 95% CI, 9.12-33.5) but not with presence of diabetic retinopathy (P = 0.61) or stage of diabetic retinopathy (P = 0.14). As a corollary, after adjusting for age, region of habitation, body mass index, systolic and diastolic blood pressure, and level of education, diabetes mellitus was associated with a thicker SFCT (P<0.001). In contrast, neither presence of diabetic retinopathy (P = 0.61) nor stage of diabetic retinopathy (P = 0.09) were associated significantly with SFCT after adjusting for body mass index, diastolic and systolic blood pressure, and level of education and after adjusting for blood glucose concentrations, HbA1c value, diagnosis of diabetes mellitus, and systolic and diastolic blood pressure, respectively. CONCLUSIONS Patients with diabetes mellitus had a slightly, but statistically significantly, thicker subfoveal choroid, whereas presence and stage of diabetic retinopathy were not associated additionally with an abnormal SFCT. Whereas diabetes mellitus as a systemic disease leads to a slight thickening of the choroid, diabetic retinopathy as an ocular disorder was not associated with choroidal thickness abnormalities after adjusting for the presence of diabetes mellitus. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Reproducibility of subfoveal choroidal thickness measurements with enhanced depth imaging by spectral-domain optical coherence tomography.

PURPOSE To measure the interobserver reproducibility and intra-observer reproducibility of subfoveal choroidal thickness measurements performed by enhanced depth imaging of spectral-domain optical coherence tomography (EDI-OCT) in a population-based setting. METHODS The Beijing Eye Study 2011 was a population-based study performed in rural and urban regions of Greater Beijing. The study included 3468 individuals with a mean age of 64.6 ± 9.8 years (range, 50-93 years). The participants underwent EDI-OCT and the subfoveal choroidal thickness (SFCT) was measured. To examine the interobserver variability, all images were assessed by two examiners independently of each other within 2 months. To examine the intra-observer reproducibility, a smaller study sample consisting of 21 eyes of 21 healthy subjects from the Tongren Eye Center was included in the study. These latter subjects were scanned 10 times with 1 minute breaks between each examination. The SFCT was measured by the same observer within 2 weeks. The intrasession within subject SD, the coefficient of variation, and the intraclass correlation coefficient (ICC) were calculated. RESULTS EDI-OCTs were performed for 3233 subjects. Mean SFCT measured by grader one and grader two were 254.6 ± 107.3 μm and 253.8 ± 107.4 μm, respectively, with a mean difference of 3.14 ± 13.1 μm (95% confidence interval, 0.0, 24.0). Bland-Altman plot showed 1.9% (61/3233) points outside the 95% limits of agreement. For the assessment of the intra-observer reproducibility, the ICC was 1.00 (P < 0.001, and the mean coefficient of variation was 0.85% ± 1.48%). CONCLUSIONS Under routine examination conditions, SFCT measurements by EDI-OCT showed a high intra-observer reproducibility and interobserver reproducibility.

Dry eye disease, dry eye symptoms and depression: the Beijing Eye Study

Aim To investigate the association between dry eye symptoms and depression in an adult population. Methods In this population-based cross-sectional study, a random sample of 1957 subjects from the Beijing Eye Study was examined for dry eye disease (DED) in 2006. All patients completed an interviewer-assisted questionnaire on dry eye symptoms and underwent measurement of tear break-up time (TBUT), slit-lamp evaluation of corneal staining and meibomian gland dysfunction (MGD), and the Schirmer test. In 2011, 1456 subjects from this sample were evaluated for depression using a depression scale. The association between depression symptoms and dry eye clinical tests was evaluated. Results Definite depression was more prevalent in patients with DED than in subjects without DED (13.7±0.4% vs 8.6±0.3%, p=0.02). The depression score was correlated with dry eye symptoms (correlation coefficient r=0.07; p=0.013) but not with TBUT (p=0.18), the Schirmer test (p=0.37), corneal staining (p=0.30) and MGD evaluation (p=0.93). In multivariate regression analysis, the risk of definite depression remained significantly associated with dry eye symptoms (p=0.028) after adjusting for lower cognitive status (p=0.01), rural region of habitation (p=0.023) and lower body weight (p=0.05). Conclusions In an older population from Beijing, depression was associated with DED and in particular with dry eye symptoms.

Industry sponsored anti-smoking ads and adolescent reactance: test of a boomerang effect

Objective: To examine whether adolescents’ exposure to youth smoking prevention ads sponsored by tobacco companies promotes intentions to smoke, curiosity about smoking, and positive attitudes toward the tobacco industry. Design: A randomised controlled experiment compared adolescents’ responses to five smoking prevention ads sponsored by a tobacco company (Philip Morris or Lorillard), or to five smoking prevention ads sponsored by a non-profit organisation (the American Legacy Foundation), or to five ads about preventing drunk driving. Setting: A large public high school in California’s central valley. Subjects: A convenience sample of 9th and 10th graders (n  =  832) ages 14–17 years. Main outcome measures: Perceptions of ad effectiveness, intention to smoke, and attitudes toward tobacco companies measured immediately after exposure. Results: As predicted, adolescents rated Philip Morris and Lorillard ads less favourably than the other youth smoking prevention ads. Adolescents’ intention to smoke did not differ as a function of ad exposure. However, exposure to Philip Morris and Lorillard ads engendered more favourable attitudes toward tobacco companies. Conclusions: This study demonstrates that industry sponsored anti-smoking ads do more to promote corporate image than to prevent youth smoking. By cultivating public opinion that is more sympathetic toward tobacco companies, the effect of such advertising is likely to be more harmful than helpful to youth.

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

PURPOSE To assess the relationship of hypertension with major eye diseases and other ocular parameters. DESIGN Population-based study. PARTICIPANTS 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. METHODS 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. MAIN OUTCOME MEASURES Blood pressure and ocular parameters, including intraocular pressure and prevalence of major ophthalmic diseases. 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 (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). CONCLUSIONS 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.

Prevalence and Associated Factors of Dyslipidemia in the Adult Chinese Population

To determine the prevalence, associated factors, awareness and control of dyslipidemia in Chinese living in Greater Beijing, we measured the serum cholesterol concentration in 3251 Chinese adults (age: 45 to 89 years) as participants of the population-based Beijing Eye Study 2006. Additional information on treatment of dyslipidemia was obtained using a standard questionnaire. The mean concentrations of total, HDL cholesterol, LDL cholesterol and triglycerides were 4.92±1.01 mmol/L, 1.61±0.36 mmol/L, 2.88±0.85 mmol/L, and 1.76±1.29 mmol/L, respectively. Prevalence of dyslipidemia was 56.1±0.9%%. Presence of dyslipidemia was significantly associated with increasing age (odds ratio (OR):1.02; 95% confidence interval (CI): 1.01, 1.03), female gender (OR:1.51; 95%CI: 1.25, 1.83), urban region (OR:1.82; 95%CI: 1.30, 2.55), body mass index (OR:1.13; 95%CI: 1.10, 1.15), income (OR:1.11; 95%CI:1.02, 1.21), blood glucose concentration (OR:1.10; 95%CI:1.05, 1.16), diastolic blood pressure (OR:1.02; 95%CI: 1.01, 1.03), and smoking (OR:1.23; 1.01, 1.51). Among those who had dyslipidemia, the proportion of subjects who were aware, treated and controlled was 50.9%, 23.8%, and 39.91%, respectively. The awareness rate was associated with urban region (P = 0.001; OR: 6.50), body mass index (P = 0.001; OR:1.06), and income (P = 0.02; OR:1.14). The data suggest that dyslipidemia may be present in about 56% of the population aged 45+ years in Greater Beijing. Factors likely associated with dyslipidemia were higher age, female gender, urban region, higher body mass index, higher income, higher blood concentration of glucose, higher diastolic blood pressure, and smoking. In the examined study population, treatment rate was 24% with about 60% of the treated subjects still having uncontrolled dyslipidemia.