Chunyi Hsu

Visual Impairment and Blindness in Adults in the United States: Demographic and Geographic Variations From 2015 to 2050

IMPORTANCE The number of individuals with visual impairment (VI) and blindness is increasing in the United States and around the globe as a result of shifting demographics and aging populations. Tracking the number and characteristics of individuals with VI and blindness is especially important given the negative effect of these conditions on physical and mental health. OBJECTIVES To determine the demographic and geographic variations in VI and blindness in adults in the US population in 2015 and to estimate the projected prevalence through 2050. DESIGN, SETTING, AND PARTICIPANTS In this population-based, cross-sectional study, data were pooled from adults 40 years and older from 6 major population-based studies on VI and blindness in the United States. Prevalence of VI and blindness were reported by age, sex, race/ethnicity, and per capita prevalence by state using the US Census projections (January 1, 2015, through December 31, 2050). MAIN OUTCOMES AND MEASURES Prevalence of VI and blindness. RESULTS In 2015, a total of 1.02 million people were blind, and approximately 3.22 million people in the United States had VI (best-corrected visual acuity in the better-seeing eye), whereas up to 8.2 million people had VI due to uncorrected refractive error. By 2050, the numbers of these conditions are projected to double to approximately 2.01 million people with blindness, 6.95 million people with VI, and 16.4 million with VI due to uncorrected refractive error. The highest numbers of these conditions in 2015 were among non-Hispanic white individuals (2.28 million), women (1.84 million), and older adults (1.61 million), and these groups will remain the most affected through 2050. However, African American individuals experience the highest prevalence of visual impairment and blindness. By 2050, the highest prevalence of VI among minorities will shift from African American individuals (15.2% in 2015 to 16.3% in 2050) to Hispanic individuals (9.9% in 2015 to 20.3% in 2050). From 2015 to 2050, the states projected to have the highest per capita prevalence of VI are Florida (2.56% in 2015 to 3.98% in 2050) and Hawaii (2.35% in 2015 and 3.93% in 2050), and the states projected to have the highest projected per capita prevalence of blindness are Mississippi (0.83% in 2015 to 1.25% in 2050) and Louisiana (0.79% in 2015 to 1.20% in 2050). CONCLUSIONS AND RELEVANCE These data suggest that vision screening for refractive error and early eye disease may reduce or prevent a high proportion of individuals from experiencing unnecessary vision loss and blindness, decrease associated costs to the US economy for medical services and lost productivity, and contribute to better quality of life. Targeted education and screening programs for non-Hispanic white women and minorities should become increasingly important because of the projected growth of these populations and their relative contribution to the overall numbers of these conditions.

The Chinese American Eye Study: Design and Methods

Abstract Purpose: To summarize the study design, operational strategies and procedures of the Chinese American Eye Study (CHES), a population-based assessment of the prevalence of visual impairment, ocular disease, and visual functioning in Chinese Americans. Methods: This population-based, cross-sectional study included 4570 Chinese participants aged 50 years and older, residing in the city of Monterey Park, California. Each eligible participant completed a detailed interview and eye examination. The interview included an assessment of demographic, behavioral and ocular risk factors and health-related and vision-related quality of life. The eye examination included measurements of visual acuity, intraocular pressure, visual fields, fundus and optic disc photography, a detailed anterior and posterior segment examination, and measurements of blood pressure, glycosylated hemoglobin levels, and blood glucose levels. Results: The objectives of the CHES are to obtain prevalence estimates of visual impairment, refractive error, diabetic retinopathy, open-angle and angle-closure glaucoma, lens opacities, and age-related macular degeneration in Chinese Americans. In addition, outcomes include effect estimates for risk factors associated with eye diseases. Lastly, CHES will investigate the genetic determinants of myopia and glaucoma. Conclusion: The CHES will provide information about the prevalence and risk factors of ocular diseases in one of the fastest growing minority groups in the United States.

Prevalence and Causes of Visual Impairment and Blindness in Chinese American Adults: The Chinese American Eye Study.

IMPORTANCE Visual impairment (VI) and blindness continue to be major public health problems worldwide. Despite previously published studies on VI in Chinese and other racial/ethnic populations, there are no data specific to Chinese American adults. OBJECTIVES To determine the age- and sex-specific prevalence and causes of VI and blindness in adult Chinese Americans and to compare the prevalence to other racial/ethnic groups. DESIGN, SETTING, AND PARTICIPANTS In this population-based, cross-sectional study of 10 US Census tracts in the city of Monterey Park, California, 4582 Chinese American adults 50 years and older underwent complete ophthalmologic examinations, including measurement of presenting and best-corrected visual acuity (BCVA) for distance using the Early Treatment Diabetic Retinopathy Study protocol from February 1, 2010, through October 31, 2013. MAIN OUTCOMES AND MEASURES Age-specific prevalence and causes of VI and blindness for presenting and BCVA. RESULTS Of the 5782 eligible adults, 4582 (79.2%) completed an in-clinic eye examination. Of the 4582 participants, most were born in China (3149 [68.7%]), female (2901 [63.3%]), and married (3458 [75.5%]). The mean (SD) age was 61 (9) years. The prevalence of presenting VI was 3.0% (95% CI, 2.5%-3.5%), with 60.0% of this prevalence being attributed to uncorrected refractive error. The overall age-adjusted prevalence for VI (BCVA of ≤20/40 in the better eye) was 1.2% (95% CI, 0.9%-1.5%). The overall age-adjusted prevalence of blindness (BCVA of ≤20/200 in the better-seeing eye) was 0.07% (95% CI, 0%-0.2%). The prevalence of VI and blindness was higher in older Chinese Americans compared with younger. The primary causes of VI were cataracts and myopic retinopathy; the primary cause of blindness was myopic retinopathy. CONCLUSIONS AND RELEVANCE The prevalence of VI in Chinese Americans is similar to that of non-Hispanic white and Latino individuals in the United States and similar to or lower than the prevalence previously reported for Chinese adults from non-US studies. The prevalence of blindness is lower than that noted in other US or non-US studies. Myopic retinopathy is a frequent cause of VI and blindness in Chinese Americans that has not been commonly observed in other racial/ethnic groups. Because myopia frequently develops at a young age, Chinese Americans should be educated regarding the importance of regular screening of preschool and school-aged children to reduce the development and progression of myopia.

Prevalence of Diabetic Retinopathy in Adult Chinese American Individuals: The Chinese American Eye Study.

Importance Chinese American individuals are a fast-growing segment of people in the United States, but the burden and effect of diabetic complications on this group of people is not fully understood. Objective To determine the age- and sex-specific prevalence of diabetic retinopathy (DR) overall and by severity, duration of diabetes, and treatment history in adult Chinese American individuals. Design, Setting, and Participants The Chinese American Eye Study (CHES), a population-based, cross-sectional study, was conducted from February 2010 to October 2013 for 10 census tracts in Monterey Park, California. This analysis, conducted between February 16, 2010, and October 9, 2013, included 4582 Chinese residents 50 years and older. Main Outcomes and Measures Prevalence of nonproliferative DR, proliferative DR, and macular edema, as well as stereoscopic fundus photography of 7 standard Early Treatment Diabetic Retinopathy Study fields. Results Of the 4582 survey participants, most were first-generation immigrants from China (68.7%) and female (63%). In total, 736 participants (16.1%) were identified as having type 2 diabetes. Fundus photographs were gradable for 665 (90.4%) of these participants. The reproducibility of DR grading was evaluated throughout study and showed moderate to excellent agreement (weighted κ = 0.78-0.97). Diabetic retinopathy was present in 35.8% of people with diabetes (95% CI, 32.1%-39.6%). The estimated prevalence of severe nonproliferative DR and proliferative DR was 1.7% (95% CI, 0.8%-2.9%) and 2.4% (95% CI, 1.4%-3.9%), respectively. Macular edema was observed among 4.5% of people with diabetes (95% CI, 3.0%-6.4%), and clinically significant macular edema was observed among 2.0% (95% CI, 1.1%-3.3%). The prevalence of DR was higher (56%) among participants with a longer duration of diabetes (≥15 years; P < .001). The prevalence of visual impairment (best-corrected visual acuity worse than 20/40 in the better-seeing eye) among participants with diabetes was higher than those without diabetes (6.7% vs 2.2% = difference of 4.5%; 95% CI, 3.9%-5.1%). The primary causes of visual impairment in participants with diabetes were cataracts (38% of participants; 95% CI, 36.6%-39.4%) followed by macular edema (7% of participants; 95% CI, 6.3%-7.7%). Conclusions and Relevance Data from CHES and this study indicate that the prevalence of DR in the Chinese American Eye Study Group is relatively lower than studies of Chinese individuals residing in rural northern China or Latino individuals from Los Angeles County, California.

Prevalence of age-related macular degeneration in Chinese American Adults: The Chinese American eye study

Importance Population-based prevalence estimates of age-related macular degeneration (AMD) need to be determined to assess its burden among Chinese Americans, the fastest growing racial group in the United States. Objective To determine the age- and sex- specific prevalence of AMD among Chinese Americans. Design The Chinese American Eye Study (CHES) was conducted in a general urban community of 10 census tracts in Monterey Park, California. A total of 4582 Chinese American adults aged 50 years or older participated in this population-based, cross-sectional study from February 16, 2010, through October 9, 2013, and underwent an interview as well as comprehensive clinical and eye examinations, including detailed retinal photography of both eyes. Fundus photographs were graded for drusen and retinal pigment epithelium abnormalities and were evaluated for AMD. Main Outcomes and Measures The prevalence of early and advanced AMD, drusen, geographic atrophy, and neovascular AMD were determined by using a modified Wisconsin Age-Related Maculopathy Grading Scale (a 6-level scale: 10, no AMD; 60, advanced AMD). Results Of the 4582 participants completing both the home survey and clinical examination, 4172 individuals (91.1%) had at least 1 gradable photograph. A total of 1526 (36.6%) participants were men, and the mean (SD) age was 61.2 (8.8) years. When examined by 10-year age groups, the prevalence of early AMD ranged from 5.8% (n = 119) in participants aged 50 to 59 years to 17.6% (n = 37) in those 80 years or older, retinal pigment epithelium abnormalities from 4.1% (n = 85) to 7.2% (n = 16), large drusen (≥125 µm) from 9.8% to 32.4%, soft drusen from 27.6% (n = 567) to 58.6% (n = 123), and soft indistinct drusen from 3.7% (n = 76) to 15.2% (n = 32). The prevalence of advanced AMD ranged from 0.2% (n = 3) in participants aged 50 to 59 years to 1.0% (n = 2) in those 80 years or older. Of the 14 cases of advanced AMD, 85.7% (95% CI, 57.2%-98.2%; n = 12) were neovascular AMD and 14.3% (95% CI, 2.0%-42.8%; n = 2) were geographic atrophy. Acute macular degeneration was more common in men (10.9% [9.3%-12.5%]; n = 166) than women (5.8% [4.9%-6.7%]; n = 154) in this cohort. Conclusions and Relevance Data from CHES suggest that Chinese Americans have a lower prevalence of early and advanced AMD compared with non-Hispanic white individuals. The prevalence of early AMD, advanced AMD, and large drusen was higher among Chinese Americans in CHES than among the Chinese population living in urban/rural China but lower than that in urban-dwelling Taiwanese.

Prevalence and Characteristics of Myopic Degeneration in an Adult Chinese American Population: The Chinese American Eye Study

PURPOSE To characterize and provide population-based prevalence estimates of myopic degeneration (MD) among Chinese Americans, the fastest-growing minority population in the United States in the last decade. DESIGN Population-based, cross-sectional study. METHODS A total of 1523 Chinese-American adults with myopia, aged 50 years and older, residing in the city of Monterey Park, California, underwent an interview and comprehensive eye examination, including subjective and objective refraction and stereoscopic fundus photography. For each participant, the eye with the worse myopic refractive error was included in this analysis. MD was assessed in a masked manner by an expert grader. RESULTS The prevalence of any MD was 44.9% among myopic subjects, based on the presence of any degenerative lesion secondary to myopia. The prevalence was 32.2% when MD was defined by a modified version of the Meta-Analysis for Pathologic Myopia. The prevalence of specific lesions included tessellation (31.7%), tilted disc (28.1%), peripapillary atrophy (7.0%), staphyloma (5.7%), diffuse atrophy (6.4%), lacquer cracks (2.6%), intrachoroidal cavitation (2.2%), patchy atrophy (0.9%), and end-stage MD (0.2%). The prevalence of MD was higher among older myopic subjects and among participants with more severe myopia and longer axial length (P < .001). CONCLUSIONS These data provide the first population-based estimates of MD in Chinese Americans and indicate that a high proportion of Chinese Americans might be at risk for MD and associated visual complications. Prevalence of MD in this cohort of Chinese Americans was higher than that observed in other East Asian populations and in people of other ethnicities.

Prevalence of Lens Opacities in Adult Chinese Americans: The Chinese American Eye Study (CHES)

Purpose We determined the age- and sex-specific prevalence of posterior subcapsular (PSC), nuclear, cortical, and mixed lens opacities in a population-based sample of Chinese-American adults. Methods A population-based sample of Chinese-Americans 50 years and older, from 10 census tracts in Monterey Park, CA, USA, underwent a detailed interview and a comprehensive clinical examination that included assessment of different types of lens opacities by the slit-lamp–based Lens Opacities Classification System II (LOCS II). All lens changes (including pseudophakia/aphakia), PSC, nuclear, and/or cortical opacities, were evaluated and graded. Results Of the 5782 eligible subjects, 4582 (79.2%) Chinese Americans aged 50 years and older completed a comprehensive eye examination. Of the participants with LOCS II grading (n = 4234/4582, 92%), 3.0% had PSC opacities, 38.1% had nuclear opacities, and 23.4% had cortical opacities. The prevalence of all lens changes was 48.0% for all age groups and was higher by 10-year increasing age groups (P < 0.0001). The prevalence of visual impairment in the better-seeing eye with cortical only, nuclear only, PSC only, and mixed opacities was 3.9%, 5.0%, 14.3%, and 9.4%, respectively. A total of 454 (9.9%) individuals had undergone cataract extraction in at least one eye. Conclusions Chinese Americans have a high prevalence of visual impairment associated with lens opacities, and a high prevalence of nuclear opacities. Public health policies and programs designed to improve cataract detection and treatment could help reduce the burden of visual impairment in Chinese Americans.