Bruce Burkemper

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.

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.

Quantitative microvascular analysis of retinal venous occlusions by spectral domain optical coherence tomography angiography

Purpose To quantitatively evaluate the retinal microvasculature in human subjects with retinal venous occlusions (RVO) using optical coherence tomography angiography (OCTA). Design Retrospective, cross-sectional, observational case series. Participants Sixty subjects (84 eyes) were included (20 BRVO, 14 CRVO, 24 unaffected fellow eyes, and 26 controls). Methods OCTA was performed on a prototype, spectral domain-OCTA system in the 3x3mm central macular region. Custom software was used to quantify morphology and density of retinal capillaries using four quantitative parameters. The vasculature of the segmented retinal layers and nonsegmented whole retina were analyzed. Main outcome measures Fractal dimension (FD), vessel density (VD), skeletal density (SD), and vessel diameter index (VDI) within the segmented retinal layers and nonsegmented whole retina vasculature. Results Nonsegmented analysis of RVO eyes demonstrated significantly lower FD (1.64±0.01 vs 1.715±0.002; p<0.001), VD (0.32±0.01 vs 0.432±0.002; p<0.001), and SD (0.073±0.004 vs 0.099±0.001; p<0.001) compared to controls. Compared to the fellow eye, FD, VD and SD were lower (p<0.001), and VDI was higher (p<0.001). FD, VD, and SD progressively decreased as the extent (or type) of RVO increased (control vs BRVO vs CRVO; p<0.001). In the unaffected fellow eye FD, VD and SD showed significant differences when compared to control eyes or affected RVO eyes (p<0.001). Conclusions Quantitative OCTA of the central 3x3mm macular region demonstrates significant differences in capillary density and morphology among subjects with BRVO and CRVO compared to controls or unaffected fellow eyes in all vascular layers. The unaffected fellow eyes also demonstrate significant differences when compared to controls. OCTA allows for noninvasive, layer-specific, quantitative evaluation of RVO-associated microvascular changes.

Factors Associated with Prevalent Diabetic Retinopathy in Chinese Americans: The Chinese American Eye Study

Objective To identify factors associated with prevalent diabetic retinopathy (DR) among Chinese American adults with type 2 diabetes mellitus (T2DM), and to compare these factors to ones previously described for a population-based sample of Latinos with a higher DR prevalence. Design Population-based cross-sectional study. Participants 4582 Chinese Americans aged 50 or older residing in Monterey Park, California. Methods Participants completed an in-home questionnaire on socio-demographic status and medical history, and a comprehensive clinical eye examination, using the same protocol implemented in the Los Angeles Latino Eye Study. Fundus photographs from 7 Early Treatment Diabetic Retinopathy fields were graded in a masked manner using a modified Airlie House grading system to assess presence and severity of DR. Logistic regression analyses based on a conceptual model of DR risk identified factors associated with prevalent DR. Main Outcome Measures Odds ratios (ORs) and 95% confidence intervals (CIs) for factors associated with DR and vision-threatening DR (VTDR). Results In total, 238 participants were diagnosed with any DR; 27 of these were classified as having VTDR. Both, any DR and VTDR showed statistically significant positive associations with T2DM duration (OR5-9 years = 1.24, OR10-14 years = 2.07, OR15+years = 3.99), glycosylated hemoglobin (HbA1c) (OR6.5-6.9% = 1.33, OR7-7.9% = 1.86, OR8%+ = 3.22), systolic blood pressure (SBP) (ORper 10mmHg+ = 1.19), and insulin treatment (ORinsulin+ = 2.44). For VTDR, we also found novel associations with antihypertensive drugs (OR: 0.18; 95% CI: 0.06-0.61) and statins (OR: 4.96; 95% CI: 1.60-16.41). Chinese Americans and Latinos had a nearly identical DR probability based on HbA1c and SBP. However, Latinos had a higher DR probability at every year of duration of T2DM (≥ 5 years). Conclusions While we observed an overall lower DR prevalence in Chinese Americans than in Latinos (35.8% of individuals with TD2M in Chinese Americans versus 42.0% in Latinos), our data indicate that the impact of increasing HbA1c and SBP on DR probability is incrementally the same in both populations. However, increasing T2DM duration is associated with higher DR probability in Latinos than Chinese Americans, even after controlling for other known predictors. Novel factors associated with VTDR include antihypertensive drugs and statins. However, to determine if these drugs impact VTDR susceptibility, we need longitudinal data and more cases.

A Population-Based Assessment of the Agreement Between Grading of Goniophotographic Images and Gonioscopy in the Chinese-American Eye Study (CHES)

Purpose To compare grading of goniophotographic images and gonioscopy in assessing the iridocorneal angle. Methods In a population-based, cross-sectional study, participants underwent gonioscopy and goniophotographic imaging during the same visit. The iridocorneal angle was classified as closed if the posterior trabecular meshwork could not be seen. A single masked observer graded the goniophotographic images, and each eye was classified as having angle closure based on the number of closed quadrants. Agreement between the methods was analyzed by calculating kappa (κ) and first-order agreement coefficient (AC1) statistics and comparison of area under receiver operating characteristic curves (AUC). Results A total of 4149 Chinese Americans (3994 eyes) were included in this study. The agreement for angle closure diagnosis between gonioscopy and EyeCam was moderate to excellent (κ = 0.60, AC1 0.90, AUC 0.76–0.80). Conclusions Detection of iridocorneal angle closure based on goniophotographic imaging shows moderate to very good agreement with angle closure assessment using gonioscopy.

The African American Eye Disease Study: Design and Methods

ABSTRACT Purpose: To describe the study design, operational and recruitment strategies, procedures, and baseline characteristics of the African American Eye Disease Study (AFEDS), a population-based assement of the prevalence of visual impairment, ocular disease, visual function, and health-related quality of life in African Americans. Methods: This population-based, cross-sectional study included over 6000 African Americans 40 years and older residing in and around Inglewood, California. A detailed interview and eye examination was performed on each eligible participant. 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 AFEDS cohort includes more than 6000 participants that have completed a home questionnaire and a comprehensive eye examination. The majority of participants were female (63%), the average (± standard deviation) overall age was 60.9 (±11.3). Participants are mostly working (40%) or retired (41%), non-smoking (57%), partial drinking (54%), and with at least some college education (38%). A trust-development recruitment strategy was refined in order to overcome challenges in study participation. Conclusion: The AFEDS is the largest epidemiologic eye study among African Americans to date. The AFEDS cohort will provide information about the prevalence and risk factors of ocular disease in the largest ophthalmologic study population of African Americans in the United States.

Comparison of surgical outcomes of trabeculectomy, Ahmed shunt, and Baerveldt shunt in uveitic glaucoma

BackgroundUveitis is defined as a collection of syndromes involving intraocular inflammation which can lead to pain, tissue damage, and vision loss. Ophthalmic surgery in uveitis patients can be challenging due to inflammation-induced fibrosis and scarring. Trabeculectomy and implantation of glaucoma drainage devices (aqueous shunts) have been used in surgical management of uveitic glaucoma, however there is a paucity of literature examining the comparative results of these entities in this unique setting. The purpose of this retrospective comparative study is to compare clinical outcomes of trabeculectomy with MMC, Ahmed shunt, and Baerveldt shunt surgery specifically in uveitic glaucoma.ResultsMedian IOP, IOP reduction, glaucoma medication use, and visual acuity at 6- and 12-month follow-up were similar across groups. Postoperative hypotony rate was significantly different across trabeculectomy (53%), Baerveldt (24%), and Ahmed (18%) groups (p = 0.027); other complication rates were similar. Baerveldt eyes had a lower failure rate compared to trabeculectomy (p = 0.0054) and Ahmed (p = 0.0008) eyes.ConclusionsWhile there was no difference in IOP reduction between trabeculectomy, Ahmed, and Baerveldt, Baerveldt eyes had the lowest failure rate.