Prevalence and associations of cataract in a rural Chinese adult population: the Handan Eye Study.

BACKGROUND: Cataract remains the leading cause of blindness and visual impairment in the world and in China. However, data on the prevalence of cataract based on standardized lens grading protocols from mainland China are limited. This paper estimated the age- and gender-specific prevalence and risk factor for cataract METHODS: In a population-based Chinese sample, participants underwent a comprehensive ophthalmic examination, including assessment of cortical, nuclear, posterior subcapsular (PSC) and mixed lens opacities from slit-lamp grading using the Lens Opacities Classification System III. RESULTS: Of the 7,557 eligible subjects, 6,830 took part in the study (90.4% response rate), and 6,544 participants (95.8%, mean age 52.0 ± 11.8 years) had lens data for analyses. The prevalence of any cataract surgery in at least one eye was 0.8% (95% confidence interval [CI], 0.62, 1.06), with similar rates between men and women. The overall prevalence of any cataract or cataract surgery was 20.8% (95% CI, 19.8, 21.8), higher in women than in men after adjusting for age (23.6% vs 17.6%; OR: 1.78; 95% CI: 1.54-2.07). When distinct lens opacity was categorized in each eye as cortical, nuclear, PSC or mixed, based on one randomly selected eye, cortical cataract was the most common distinct subtype (12.3%), followed by mixed (3.2%), nuclear (1.7%), and PSC (0.2%) cataract. The prevalence of all lens opacities increased with age (P < 0.001). After excluding other causes for visual impairment, the proportion of people with best corrected visual acuity <20/60 was 21% among those with PSC, and 12% among those with mixed opacities in the better-seeing eye. In multivariable logistic regression models, myopia was associated with all cataract types, while higher fasting plasma glucose and diabetes were only associated with PSC cataract. CONCLUSIONS: Cataract affects 20% of the population aged 30 years and older living in rural China, with cortical cataract the most common subtype. Risk factors for cataract include myopia and diabetes.

Association of dilated retinal arteriolar caliber with early age-related macular degeneration: the Handan Eye Study.

BACKGROUND: To identify factors associated with early age-related macular degeneration (AMD) in a rural Chinese population, with emphasis on retinal vessel caliber. METHODS: The study population comprised the 6,830 participants of the Handan Eye Study. All participants underwent digital retinal photography of both eyes. Trained graders assessed the presence of AMD lesions. Arteriolar and venular diameters were measured with a specific computer-assisted program and were summarized as the central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). RESULTS: The data for the 199 individuals with evaluable retinal photographs and early AMD and 400 age-matched individuals randomly selected from the group without AMD were analyzed. After adjusting for participants' age, sex, smoking status, hypertension, diabetes, BMI, and CRVE, the multivariate adjusted model showed that a higher CRAE was significantly associated with early AMD (OR = 1.34; 95% CI: 1.05-1.71; p = 0.020) and the presence of soft distinct drusen (OR = 1.32 (95% CI: 1.02-1.71, p = 0.037). There were no significant associations between CRVE and early AMD. CONCLUSIONS: Dilated retinal arteriolar caliber is associated with early AMD and soft distinct drusen in this population. We found no significant associations between CRAE and other characteristics of the retina related to AMD or between retinal venal caliber and early AMD. More research is needed to determine whether the difference between these results and those previously published stem from the rural living conditions of the participants or other factors.

Prevalence and causes of amblyopia in a rural adult population of Chinese the Handan Eye Study.

OBJECTIVE: To determine the prevalence of and factors associated with amblyopia in a rural Chinese population. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Six thousand eight hundred thirty Han Chinese aged 30 years or more, recruited from Yongnian County, Handan, Hebei Province, China. METHODS: Thirteen villages in the Yongnian County of Handan were selected randomly, and residents of these selected villages 30 years of age or older were invited to participate in the Handan Eye Study. Participants underwent a comprehensive eye examination, including standardized visual acuity (VA) tests using logarithm of the minimum angle of resolution charts. Prevalence rates were age- and gender-standardized to the 2000 China census. MAIN OUTCOME MEASURES: The proportion of rural Chinese population aged 30 years or older with amblyopia. Unilateral amblyopia was diagnosed if best-corrected VA (BCVA) was 20/32 or worse in the amblyopic eye and was not attributable directly to any underlying structural abnormality of the eye or visual pathway. Bilateral amblyopia was diagnosed if BCVA was 20/32 or less in both eyes and if there was a history of form deprivation during the sensitive period of visual development, such as media opacities or high, uncorrected ametropia. RESULTS: Amblyopia was diagnosed in 205 participants, with an age- and gender-adjusted prevalence of 2.8%. Of these, 1.7% were unilateral cases and 1.1% were bilateral cases. Underlying causes included anisometropia (67.3%), strabismus (5.4%), mixed strabismus and anisometropia (4.4%), visual deprivation (9.8%), astigmatism association (9.8%), and other (3.4%). Of the amblyopia cases, 47.6% were hypermetropic. CONCLUSIONS: In this rural Chinese population, 2.8% of adults 30 to 80 years of age had amblyopia, a prevalence rate broadly consistent with that of most other studies. One third of the cases were bilateral, and anisometropia was the most common cause of this condition.

Prevalence of age-related macular degeneration in a rural Chinese population: the Handan Eye Study.

PURPOSE: To describe the prevalence of age-related degeneration (AMD) in a rural Chinese population and to assess its associations with age, gender, and smoking. DESIGN: Population-based cross-sectional. PARTICIPANTS: Persons aged 30+ years, recruited between October 2006 and October 2007, from Yongnian County, Handan, Hebei Province, China. METHODS: All participants underwent a standardized interview and comprehensive eye examinations, including digital retinal photography of both eyes. Trained graders assessed the presence and severity of AMD lesions following the modified Wisconsin Age-related Maculopathy Grading System (WARMGS) used in the Blue Mountains Eye Study (BMES). Direct age standardization to the world population (year 2000) was performed to compare the prevalence across different populations. MAIN OUTCOME MEASURES: AMD and WARMGS. RESULTS: Of 6830 participates, fundus photographs were gradable for 6581 persons (96.4%), including 4049 aged 50+ years. Early and late AMD prevalence rates were 3.0% and 0.1%, respectively, among participants. The age-standardized prevalence rates among participants aged 50+ years were 4.7% and 0.2%, respectively. After controlling for age, men had a higher prevalence of early (3.9% vs. 2.3%, odds ratio [OR] 1.7; 95% confidence interval [CI], 1.3-2.2) and late AMD (0.1% vs. 0.03%; OR 3.5; CI, 0.4-33.4) compared with women. Older age (sex-adjusted OR 1.7; CI, 1.3-2.2 per decade of age) and current smoking (age-sex-adjusted OR 1.4; CI, 1.0-2.1) were significantly associated with early AMD prevalence. The proportion of current smokers was substantially higher in men (58.7%) than in women (0.3%). The attributable risk of early AMD from smoking among Chinese men was 24.2%. After controlling for current smoking, the excess prevalence of early AMD in men compared with women reduced by 50% (OR 1.4; 95% CI, 0.9-2.0). CONCLUSIONS: The prevalence of early AMD in this rural Chinese sample was similar to white persons in the BMES and Asian Malays in the Singapore Malay Eye Study. Late AMD prevalence, however, was lower. Higher prevalence rates for early and late AMD in men compared with women were largely attributed to substantially higher proportions of smokers in rural Chinese men than in women.

[Physical exercise and intraocular pressure].

In the 1960s, it had been observed that physical exercises could reduce the intraocular pressure (IOP) in patients with glaucoma. However, the effect of IOP reduction varied with exercise type and intensity, as well as the duration after exercise. Difference of lowering the IOP in glaucoma patients and healthy people were also observed. The mechanisms of reducing the IOP by exercise were very complicated and believed to be associated with the lower concentration of norepinephrine, the rising of colloid osmotic pressure, the co-action of nitric oxide and endothelin after exercise, and also related to the gene polymorphism of ß2-adrenergic receptor. Physical exercise, such as jogging, walking and bicycle riding, could be suggested as a complimentary therapy in addition to the pharmaceutical and surgical therapies available for glaucoma patients, even though the mechanism for lowering IOP is not clear enough.

[Alteration of anterior chamber and angle structure in eyes with primary angle closure after laser peripheral iridotomy].

OBJECTIVE: To quantitatively evaluate the long-term changes in anterior segment morphology by using ultrasound biomicroscopy (UBM) after laser peripheral iridotomy (LPI) in eyes with primary angle closure (PAC). METHODS: This was a clinical case series study. A total of 54 eyes with PAC of 31 consecutive patients were enrolled. Routine ophthalmic and UBM examination were performed at visit one (before LPI), 2 weeks, 6, and 12 months after LPI. The parameters of anterior chamber were measured by UBM and calculated. Results of each follow-up time were analyzed using repeated measures analysis of variance. Parameters of UBM measurement at 750 µm anterior to the sclera spur and at 500 µm counterpart were compared using paired student t-test. RESULTS: Compared to before LPI, anterior chamber depth (ACD) was deepened by approximate 0.10 mm after LPI, however, it was not statistically significant (F = 3.50, P > 0.05). Angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) and trabecular-ciliary process distance (TCPD) were significantly increased at 2 weeks, 6 and 12 months after LPI compared with respective baseline [AOD750: (165.0 ± 70.3), (185.8 ± 68.5), (196.1 ± 77.7) µm vs (66.2 ± 51.6) µm, F = 92.60; TIA750: 14.1° ± 6.3°, 15.5° ± 6.2°, 16.4° ± 5.9° vs 6.4° ± 4.9°, F = 92.60; ARA: (0.058 ± 0.024), (0.065 ± 0.023), (0.068 ± 0.026) mm(2) vs (0.025 ± 0.017) mm(2), F = 92.60; TCPD: (647.1 ± 113.0), (701.8 ± 93.4), (670.1 ± 95.4) µm vs (571.0 ± 97.2) µm, F = 34.00; P < 0.05]. The parameters of UMB measurement at 750 µm were significantly increased more than that at 500 µm anterior to the sclera spur (AOD: t = 5.90, TIA750: t = 2.70, P < 0.05; ARA: t = 2.00, P = 0.05). CONCLUSIONS: LPI can significantly widen the peripheral anterior angle in eyes with PAC lasting for at least 1 year after LPI. Parameters detected by UBM at 750 µm anterior to the sclera spur appear to be more sensitive in evaluating the alternation of peripheral angle structure.

[Assess correlation between bleb morphology at long-term intraocular pressure effect in primary angle-closure glaucoma following trabeculectomy].

OBJECTIVE: To evaluate the correlation between morphologic appearance of blebs at 3 month and long-term intraocular pressure (IOP) effect in patients with primary angle-closure glaucoma (PACG) after trabeculectomy. METHODS: Multi-centered cases series. Data were collected from 176 patients aged ≥ 40 years with PACG who were participated in a randomized clinical trial that aimed at addressing the efficacy of augmented releasable sutures after trabeculectomy. The bleb morphology was graded using the Modified Indian Bleb Appearance Grading Scale (IBAGS) based on standard photos at 3 month after trabeculectomy. IOPs were measured with Goldmann applanation tonometer. The correlation between bleb components and other selected testing influencing factors and long-term IOP was tested by linear Logistic regression analysis. RESULTS: 150 patients (85.7%) completed 18 months of follow up. IOP was (15.6 ± 5.4) mm Hg at 18 month of post-operation. 135 eyes had an IOP ≤ 21 mm Hg without additional medications, 10 eyes ≥ 21 mm Hg, and the remaining 5 eyes required one or two medications to maintain normal IOP. Using IBAGS system, bleb was graded in 142 eyes as follows: H(0) in 3 eyes, H(1) in 45 eyes, H(2) in 90 eyes, and H(3) in 4 eyes, while V(0) was observed in 66 eyes, V(1-3) in 76 eyes. IOP at 18 months in bleb with microcysts was 2.77 mm Hg lower (ß = -2.77, 95%CI = -0.46 to -5.08) than those without microcysts and in bleb with non-vascular was 2.07 mm Hg lower (ß = -2.07, 95%CI = -0.15 to -3.98) than those with vascular at 3 months after surgery. IOP was significantly (ß = -1.20, 95%CI: -0.00 to -2.40) decreased by 1.2 mm Hg with 10 years of age increase (P < 0.05). CONCLUSIONS: Early filtering bleb with microcysts, vascular, and age are identified as important factors to predict long-term IOP effect in patients with PACG after trabeculectomy but not early morphological appearance of filtering bleb.

Retinopathy in persons without diabetes: the Handan Eye Study.

PURPOSE: To describe the prevalence and associations of retinopathy in a population-based nondiabetic sample of rural Chinese. DESIGN: Population-based cross-sectional study. PARTICIPANTS: We included 6830 Han Chinese aged > or =30 years from 13 villages of Yongnian County, Handan City, Hebei Province, China. METHODS: All participants underwent a standardized interview and extensive examinations including retinal photography, measurement of blood pressure (BP) and fasting plasma glucose (FPG). Diabetes mellitus was defined as either FPG > or = 7.0 mmol/l, use of diabetic medication or a physician diagnosis of diabetes. Photographic grading of retinopathy followed the modified Early Treatment Diabetic Retinopathy Study classification system. Logistic regression models were used to assess associations of retinopathy. MAIN OUTCOME MEASURES: Any retinopathy. RESULTS: The prevalence of retinopathy among participants without diabetes was 13.6% (95% confidence interval [CI], 12.6-14.6%). The age and gender standardized prevalence of retinopathy in the Chinese adult population (aged 30+ years) without diabetes was estimated to be 12.1% (95% CI 11.1-12.9%). Independent risk factors associated with retinopathy were age (odds ratio [OR], 1.02 ; 95% CI 1.01-1.03 per year increase), male gender (male vs. female, OR 1.27; 95% CI 1.08-1.49), higher FPG (OR 1.30; 95% CI 1.11-1.53 per mmol/l increase), higher systolic BP (OR 1.15; 95% CI 1.05-1.27 per 10 mmHg increase) and higher diastolic BP (OR 1.16; 95% CI 1.09-1.22 per 10 mmHg increase). CONCLUSIONS: Retinopathy was common among rural Chinese adults without diabetes. Its association with FPG and BP suggests that early microvascular damage is occurring at "high normal" levels of blood glucose and BP.

Normal macular thickness measurements using optical coherence tomography in healthy eyes of adult Chinese persons: the Handan Eye Study.

PURPOSE: To describe macular thickness measured by optical coherence tomography (OCT) in healthy eyes of adult Chinese persons. DESIGN: Population-based cross-sectional study. PARTICIPANTS: Chinese adults aged 30+ years who were residents of Handan, North China. METHODS: The Handan Eye Study is a population-based study of eye disease in Chinese persons. Eligible residents underwent a comprehensive ophthalmic examination including OCT (Stratus OCT, Carl Zeiss Meditec Inc., Jena, Germany). Fast macular thickness scans were performed over maculae within 6 mm in diameter, divided into 3 regions (central, inner, and outer, with a diameter of 1, 3, and 6 mm, respectively) and 9 quadrants (1 in the central region and 4 each in the inner and outer regions). Retinal thickness (means and standard deviations) was calculated by OCT mapping software, presented for foveal minimum, central macula (within 1 mm diameter), and inner and outer regions divided by 8 quadrants. MAIN OUTCOME MEASURES: Macular thickness measured by OCT. RESULTS: Of the 6830 participants (90.4% response rate) examined, 2230 eyes of healthy subjects with high-quality OCT scans were selected (32.7% of participants; mean age, 46.4+/-9.9 years, 58.4% were women). The mean foveal minimum, central, inner, and outer macular thicknesses were 150.3 (18.1) microm, 176.4 (17.5) microm, 255.3 (14.9) microm, and 237.7 (12.4) microm, respectively (overall differences, P<0.001). The mean foveal volume was 0.139 (0.014) mm(3), and the mean total macular volume was 6.761 (0.516) mm(3). In the inner region, the nasal quadrant was thinner than the superior and inferior quadrants, and in the outer region, the nasal quadrant was the thickest (P<0.001). Age was positively correlated with foveal (beta coefficient = 3.582) and central macular (beta coefficient = 2.422) thicknesses. The foveal minimum, central, inner, and outer macular thicknesses were significantly greater in men than in women. Fasting plasma glucose was negatively correlated with central macular thickness (2.416 mm reduction per millimole/liter increase in glucose), and axial length was positively correlated with central macular thickness (2.138 mm increase per millimeter increase in axial length). CONCLUSIONS: Normal macular thickness measurements using OCT in a large population-based sample of adult Chinese persons aged 30 to 85 years were generally thinner in the foveal and central macular areas than measurements reported in other populations. Age and axial length were positively correlated with macular thickness.

Refractive errors in a rural Chinese adult population the Handan eye study.

PURPOSE: To describe the prevalence of and risk factors for myopia and other refractive errors in a rural, adult, Chinese population. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A clustered, random sampling procedure was used to select 7557 Chinese people aged >or=30 years from Handan, China. METHODS: All eligible subjects were invited to undergo a comprehensive eye examination, including standardized refraction. Myopia, high myopia, and hyperopia were defined as a spherical equivalent (SE) in the right eye of more than -0.5 diopter (D), less than -5.0 D, and 0.5 D or more, respectively. Astigmatism was less than -0.5 D of cylinder. Anisometropia was defined as a difference in SE of >1.0 D between the 2 eyes. Only phakic eyes were analyzed. MAIN OUTCOME MEASURES: Myopia and other refractive errors. RESULTS: We included 6491 (85.9% participation rate) eligible subjects in this study. Adjusted to the 2000 China population census, the prevalence rate of myopia was 26.7% (95% confidence interval [CI], 25.6-27.8), hyperopia 15.9 % (95% CI, 15.0-16.8), astigmatism 24.5% (95% CI, 23.5-25.5), and anisometropia 7.7% (95% CI, 7.0-8.4). The prevalence of high myopia was 1.8% (95% CI, 1.5-2.1). Using a multivariate regression model, current smoking (odds ratio [OR], 0.7, 95% CI, 0.5-0.9), hours of reading (OR, 1.2; 95% CI, 1.1-1.4), diabetes (OR, 8.4; 95% CI, 2.2-32.5), and number of family members with myopia (OR, 1.3; 95% CI, 1.1-1.7, for each family member) were associated with myopia in younger persons (30-49 years). High school or higher education (OR, 1.8; 95% CI, 1.1-3.1), diabetes (OR, 1.6; 95% CI, 1.2-2.7), nuclear opacity (OR, 1.7; 95% CI, 1.2-2.3), and number of family members with myopia (OR, 1.5; 95% CI, 1.2-1.9) were risk factors in persons >or=50 years of age. CONCLUSIONS: Myopia affects more than one quarter of rural Chinese persons >or=30 years of age. Myopia is more common in younger people and is associated with different risk factors than in older people.

Prevalence of diabetic retinopathy in rural China: the Handan Eye Study.

PURPOSE: To describe the age- and gender-specific prevalence, characteristics, and severity of diabetic retinopathy (DR) in a rural population in northern China. DESIGN: A population-based cross-sectional study. PARTICIPANTS: A total of 6830 Han Chinese aged 30 years and older from 13 villages of Yongnian County, Handan City, Hebei Province, China. METHODS: All participants underwent a standardized interview, a comprehensive eye examination, and fasting blood glucose testing according to the American Diabetes Association diagnostic criteria (fasting plasma glucose >or=7.0 mmol/l). Retinal photographs obtained after pupil dilation were graded for the presence and severity of DR according to the modified Early Treatment Diabetic Retinopathy Study classification system. MAIN OUTCOME MEASURES: Any DR, retinopathy grades, macular edema, or vision-threatening retinopathy. RESULTS: Of the 6830 eligible individuals participating in the study, 5597 (81.9%) had fasting blood glucose results available. Of these, 387 participants (6.9%) were diagnosed with diabetes mellitus, including 247 subjects with new diabetes mellitus (NDM) and 140 subjects with known diabetes mellitus (KDM). For these, gradable photographs were available for 368 subjects (95.1%). The overall prevalence of DR was 43.1% (95% confidence interval, 38.1-48.4) and was higher in persons with KDM (65.2%) than NDM (33.5%). The prevalence of proliferative DR, macular edema, and vision-threatening retinopathy was 1.6%, 5.2%, and 6.3%, respectively, with 12.1% with KDM having untreated vision-threatening DR. No age- or gender-related differences were present. The prevalence of DR was strongly related to duration of disease. CONCLUSIONS: Our study reports a high prevalence of DR among adults 30 years and older with diabetes in rural China. On the basis of estimates obtained from our study, we projected that in rural China, 21.1 million persons aged 30+ years have diabetes and 9.2 million have DR, including 1.3 million with vision-threatening DR. There is a pressing need for appropriate screening and management of diabetes and its complications in rural China.

Distributions of angiogenesis and lymphangiogenesis in gastrointestinal intramucosal tumors.

BACKGROUND: Although angiogenesis and lymphangiogenesis in gastrointestinal cancers has been investigated in many studies, their distribution characteristics in gastrointestinal intramucosal tumors have not been well addressed. METHODS: We evaluated the blood microvessel density (BMVD) and lymphatic microvessel density (LMVD) by immunostaining with monoclonal antibodies of CD34 and D2-40 in 37 patients with stomach intramucosal carcinoma and 28 patients with colorectal intramucosal neoplasia. Microvessels with endothelial cells labeled by CD34 but not by D2-40 were recognized as blood microvessels; and microvessels with endothelial cells labeled by both CD34 and D2-40 were recognized as lymphatic vessels. Furthermore, the relationships between expression of vascular endothelial growth factor (VEGF), VEGF-C, and BMVD, LMVD were investigated as well. RESULTS: The LMVD was significantly higher in peritumoral tissues than in corresponding normal tissues in gastrointestinal intramucosal tumors (20.87 versus 14.56, P = 0.003). However, there was no significant difference in the BMVD between peritumoral tissues and corresponding normal tissues (P = 0.166). The BMVD in peritumoral tissues was higher in patients with lymph node metastases than in patients without lymph nodes metastases (P = 0.047). Our results did not show significant association between VEGF, VEGF-C and BMVD, LMVD. CONCLUSIONS: Our results suggested that the increase of lymphangiogenesis seems superior to the increase of angiogenesis in gastrointestinal intramucosal tumors.

Prevalence and causes of low vision and blindness in a rural chinese adult population: the Handan Eye Study.

PURPOSE: To describe the prevalence and causes of low vision and blindness in a rural population in Northern China. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A study of 6830 Han Chinese aged 30 years and older was conducted between October 2006 and October 2007 in rural Yongnian County in Handan, Northern China. METHODS: Clustered samples of adults aged 30 years or more residing in 13 residential villages were selected randomly and were invited to participate the Handan Eye Study. Participants underwent a comprehensive eye examination, including standardized visual acuity (VA) tests using logarithm of the minimum angle resolution charts. Prevalence was age- and gender-standardized to the 2000 China Census. MAIN OUTCOME MEASURES: Low vision was defined as VA <20/60 but >/=20/400, and blindness was defined as VA <20/400 following the Modified World Health Organization (WHO) definitions. Primary causes of low vision and blindness were determined by study ophthalmologists according to WHO definitions. RESULTS: Six thousand eight hundred thirty (90.4%) of 7577 eligible individuals participated in the study, and 6799 (89.7%) had VA data available. Population-weighted prevalence of presenting bilateral blindness was 0.6% and bilateral low vision was 4.7% for persons 30 years of age and older. Based on best-corrected visual acuity (BCVA), the corresponding prevalence of blindness was 0.5% and that of low vision was 1.0%. Blindness and low vision were strongly age related (P<0.05). Cataract was the predominant cause of presenting bilateral blindness (36.6%), whereas undercorrected refractive error was the predominant cause of presenting low vision (78.4%). After refractive correction, cataract became the first leading cause of blindness (41.9%), and low vision (48.2%), myopic retinopathy (16.1%), glaucoma (9.7%), and corneal opacity (9.7%) were other common causes of blindness defined using BCVA. CONCLUSIONS: A higher prevalence of blindness and low vision was seen in this rural Chinese sample than has been reported from urban Chinese populations. The estimated numbers with BCVA-defined low vision and blindness in 2020, based on best-corrected vision in rural Chinese adults aged 30 years or more, is expected to be 12.4 million and 2.9 million, respectively. Predominant causes of low vision and blindness in China are treatable.

A Population-Based Assessment of 24-Hour Ocular Perfusion Pressure Among Patients With Primary Open Angle Glaucoma: The Handan Eye Study.

PURPOSE: To compare the 24-hour ocular perfusion pressure (OPP) among patients with primary open angle glaucoma (POAG) and those with suspected POAG identified in a population-based study in China. METHODS: Forty-seven patients with POAG and 35 with suspected POAG attended the 24-hour OPP study. Intraocular pressure (IOP) and blood pressure (BP) were measured at 2, 6, and 10 AM and 2, 6, and 10 PM. Subjects were not taking any medications to lower IOP, which was measured with Goldmann applanation in an upright sitting position. Blood pressure was measured in a supine position using a digital automatic BP monitor (OMRON, model HEM-907). Mean arterial pressure was calculated as diastolic BP + 1[Fraction Slash]3 × (systolic BP - diastolic BP). Mean OPP (MOPP) was defined as 2[Fraction Slash]3 × mean arterial pressure - IOP, systolic OPP (SOPP) was defined as 2[Fraction Slash]3 × systolic BP - IOP, and diastolic OPP (DOPP) was defined as 2[Fraction Slash]3 × diastolic BP - IOP. RESULTS: After adjustment for age, sex, and IOP, the maximum, mean, and minimum SOPP, DOPP, and MOPP were statistically significantly lower in subjects with POAG than in those with suspected POAG (P < 0.05). The minimum MOPP, SOPP, and DOPP occurred from 10 AM to 2 PM in approximately 60% of eyes with POAG and between 20% and 30% of minimum MOPP, SOPP, and DOPP occurred around 10 PM. CONCLUSIONS: Systolic OPP, DOPP, and MOPP were consistently lower in eyes with POAG than in those with suspected POAG, providing further evidence that OPP plays a role in the development of glaucoma.

Rationale, design, and demographic characteristics of the Handan Offspring Myopia Study.

PURPOSE: The Handan Offspring Myopia Study (HOMS) aims to investigate the familial associations of myopia between parents and their offspring. METHODS: Children aged 6-18 years, residing in 6 villages where all people aged ≥30 years had participated in The Handan Eye Study in 2006-2007, were selected for the current eye study between March and June 2010. A mobile clinic was set up in the 6 villages for comprehensive eye examinations, including visual acuity, ocular biometry, cycloplegic autorefraction and retinal photography. RESULTS: Of 1238 eligible individuals, 878 children (70.2%; 52.6% male) from 541 families were recruited. Mean age of the children was 10.5 ± 2.5 years. The prevalence of myopia (spherical equivalent refraction <-0.5 diopter) was 23.5% (males 16.8%, females 30.8%). The prevalence of low vision (presenting visual acuity ≥20/400 but <20/60) in the better eye was 7.1%. A higher number of females had low vision at the time of presentation (9.2%) compared to males (5.2%, p = 0.02). The prevalence of low vision in the worse eye was 10.6% (males 6.7%, females 14.9%, p < 0.001). The majority of visual impairment in the better-seeing (56/62, 90.3%) as well as the worse-seeing (84/93, 90.3%) eye was correctable. CONCLUSIONS: The HOMS examined about 70% of eligible Han Chinese offspring of Handan Eye Study participants in a rural region of northern China. Results from the HOMS will provide key information about the prevalence of refractive errors and eye diseases in rural Chinese children.

Eye care use among rural adults in China: the Handan Eye Study.

PURPOSE: To assess the use of eye care services in a rural population in North China and to analyze the factors associated with underuse of these services. METHODS: In a cross-sectional population-based study, demographic, health and vision-related information including use of eye care services were determined during a face-to-face interview. A single visit to an eye care provider qualified as "use" of eye care services. RESULTS: Of 6612 participants, 754 (11.4%, 95% confidence interval, CI, 8.7-14.1%) had used eye care services. The most common reason cited for not seeing an eye care provider was "no need" (n = 5754). Of the 5754 who thought that there was no need to see an ophthalmologist, 3458 (60.1%) were found to have one or more type of eye disease, including glaucoma (56, 1.0%), cataract (1056, 18.4%), age-related macular degeneration (AMD; 164, 2.9%) and refractive error (3048, 53.0%). Also, 74 (1.3%) and 409 (7.1%) of the 5754 participants had visual impairment (<20/60) according to best-corrected visual acuity and presenting visual acuity, respectively. In a multiple regression model, participants who had glaucoma (adjusted odds ratio, OR, 4.0, 95% CI 3.0-5.4), AMD (adjusted OR 1.6, 95% CI 1.2-2.3) or refractive error (adjusted OR 1.4, 95% CI 1.1-1.8), were more likely to visit an eye care provider. CONCLUSION: A high proportion of the Chinese rural population had never used eye care services although three fifths had eye diseases. Further efforts towards better education of the general population about common eye problems as well as increasing the number of ocular health providers would be necessary in future.

The prevalence of and risk factors associated with pterygium in a rural adult Chinese population: the Handan Eye Study.

PURPOSE: To describe the prevalence and risk factors for pterygium in a rural adult Chinese population. METHODS: A total of 7557 people aged 30 years and over were randomly selected from 13 villages in a rural county, Yongnian, within Handan district, Hebei Province of China. All eligible subjects were invited to undergo a comprehensive eye examination. A slit-lamp was used to examine the anterior segment for evidence of pterygium. Pterygium was graded for severity (G1 to G3) by visibility of episcleral vessels. RESULTS: Of 6685 participants (88.5% of 7557) included in this study, pterygium was present in 401 (6.0%). Using direct standardization to the 2000 China population census for rural residents, the prevalence of pterygium was 7.1% (95% confidence interval [CI], 6.5-7.8%) among subjects aged 40+ years, and 4.8% (95% CI 4.3-5.3%) when including those aged 30-39 years. Pterygium was more common in men than in women (age-adjusted odds ratio [OR] 2.0, 95% CI 1.4-2.8). Prevalence increased with age (OR 1.8, 95% CI 1.6-2.1 per decade increase in age). Current smoking appeared to be protective (OR 0.5, 95% CI 0.4-0.7). Of eyes with any pterygium, 4.6% (95% CI 1.9-7.3%) had low vision. CONCLUSION: Approximately one in ten adults had pterygium in this rural Chinese population. Age and male sex were positively, and current smoking negatively associated with the prevalence of pterygium.

Intraocular pressure and its relationship to ocular and systemic factors in a healthy Chinese rural population: the Handan Eye Study.

PURPOSE: To describe the distribution of and factors related to intraocular pressure (IOP) in a healthy adult rural Chinese population in northern China. METHODS: The Handan Eye Study is a cross-sectional, population-based study of eye diseases among 6,830 (90.4% response rate) rural Chinese persons aged 30+ years. Participants underwent an interviewer-administered questionnaire and a complete ocular examination, including standardized measurement of IOP with Perkins applanation tonometry. RESULTS: After excluding persons with glaucoma, or those with diseases that have a marked effect on IOP or that preclude accurate IOP measurement, 6,101 persons were included in the current analysis. Mean IOP (mean ± standard deviation) of the study population was 15.0 ± 2.8 mmHg. Men had lower IOP than women (14.6 ± 2.8 mmHg versus 15.4 ± 2.7 mmHg, t = -8.37, P < 0.001). In the multivariate analysis younger age, female sex, presence of diabetes mellitus, higher blood pressure, higher body mass index, thicker central cornea and higher myopia were associated with higher IOP. CONCLUSIONS: Mean IOP among persons living in rural northern China was similar to that recently reported in southern China. IOP appeared to be lower with increasing age in Chinese subjects, which contrasts with results in white populations.

Prevalence and characteristics of primary angle-closure diseases in a rural adult Chinese population: the Handan Eye Study.

PURPOSE: To investigate the prevalence and characteristics of primary angle-closure suspect (PACS), primary angle closure (PAC), and primary angle-closure glaucoma (PACG) in a rural population in China. METHODS: In all, 6716 Han Chinese 30 years of age and older (5480 subjects 40 years of age and older) from 13 villages in Handan were randomly selected and completed an ophthalmologic examination, including visual acuity, intraocular pressure (IOP), slit-lamp examination, gonioscopy and stereoscopic photography, and visual field. PACS was defined as present if either eye had the posterior trabecular meshwork not visible for 180° or more on gonioscopy. PAC was present in an eye with PACS and peripheral anterior synechiae (PAS) and/or IOP ≥ 21 mm Hg, but without glaucomatous neuropathy (GON). PACG was defined as PAC with evidence of GON. RESULTS: The standardized prevalences of PACG, PAC, and PACS were 0.5% (95% confidence interval [CI]: 0.3-0.7%), 1.5% (95% CI: 1.2-1.8%), and 10.4% (95% CI: 9.6-11.2%) in those 40 years of age and older. The prevalence of all three conditions increased with age (P < 0.001). Females had much higher rates of PACS, PAC, and PACG (P < 0.05); 21 persons with PACG (65%) were blind in at least one eye: 13 were due to glaucoma and the other 8 likely had other causes. CONCLUSIONS: The prevalence of PACS, PAC, and PACG in this rural population is similar to what was previously reported in urban Chinese residents. Two thirds of those with PACG were blind in at least one eye. Strategies to detect and treat this preventable disease in rural China are needed.

Prevalence of primary open angle glaucoma in a rural adult Chinese population: the Handan eye study.

PURPOSE: To estimate the prevalence and associations of primary open angle glaucoma (POAG) in a rural population of northern China. METHODS: In a rural county in Handan, China, 6716 adults residing in 13 villages were randomly selected and participated in the study. All participants completed a comprehensive eye examination, including intraocular pressure (IOP), slit-lamp examination, and fundus evaluation. Visual fields were obtained with on glaucoma suspects. RESULTS: Sixty-five persons (1.2%) had POAG, with an adjusted prevalence of 1.0% (95% confidence interval [CI], 0.7% -1.3%) in those aged 40 years and older. Sex was not significantly associated with POAG (P > 0.05). Age (odds ratio [OR], 1.9; 95% CI, 1.4-2.5, for each 10-year increase), IOP (OR, 1.5; 95% CI 1.2-2.0 for each 5-mm Hg increase), axial length (OR, 1.3; 95% CI, 1.1-1.6), and moderate myopia (3.1-6.0 D; OR, 4.7; 95% CI, 1.6-13.5) increased the risk for POAG in multivariate analysis. The mean IOP of persons with POAG was 16.3 ± 3.5 mm Hg, and 90% of them presented with an IOP ≤ 21 mm Hg. Of those with POAG, 4.5% were blind from glaucoma in at least one eye. CONCLUSIONS: Approximately 1% of adults aged 40 years and older living in rural China have POAG. As seen in other populations, increasing age, higher IOP, greater axial length, and having myopia were associated with POAG. Given the rapid aging and myopic shift (acquired myopia) in China's population, POAG is likely to increase in prevalence in the coming decades.