Effects of an Aging Population and Racial Demographics on Eye Disease Prevalence: Projections for Georgia Through 2050

Journal Pre-proof Effects of an Aging Population and Racial Demographics on Eye Disease Prevalence: Projections for Georgia through 2050 Elaine Kelly, MD, MSc, Qing Wen, PhD, MSc, Danny Haddad, MD, Jacquelyn O’Banion, MD, MSc PII:

S0002-9394(19)30532-X

DOI:

https://doi.org/10.1016/j.ajo.2019.10.028

Reference:

AJOPHT 11121

To appear in:

American Journal of Ophthalmology

Received Date: 5 July 2019 Revised Date:

24 October 2019

Accepted Date: 25 October 2019

Please cite this article as: Kelly E, Wen Q, Haddad D, O’Banion J, Effects of an Aging Population and Racial Demographics on Eye Disease Prevalence: Projections for Georgia through 2050, American Journal of Ophthalmology (2019), doi: https://doi.org/10.1016/j.ajo.2019.10.028. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier Inc.

A Vision for Georgia: Prevalence of Disease in 2050

Effects of an Aging Population and Racial Demographics on Eye Disease Prevalence: Projections for Georgia through 2050 Authors: Elaine Kelly, MD, MSc Hofstra University School of Medicine1 Qing Wen, PhD, MSc Centre for Public Health School of Medicine, Dentistry and Biomedical Sciences Queen's University Belfast Danny Haddad, MD, Orbis International Corresponding Author: Jacquelyn O’Banion, MD, MSc Assistant Professor of Ophthalmology Emory University School of Medicine Department of Ophthalmology 1365 Clifton Rd NE Clinic Building B, Suite 2500 Atlanta, GA 30306 [email protected] 4703990004

Short Title: A Vision for Georgia: Prevalence of Disease in 2050

1

Dr. Kelly is now at Rush University Medical Center Department of Ophthalmology

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A Vision for Georgia: Prevalence of Disease in 2050

Introduction Visual impairment and blindness currently burden millions of Americans. As of 2012, Prevent Blindness America estimates that 2.91 million Americans visually impaired, with best corrected visual acuity worse than 20/40 but better than 20/200. An additional estimated 1.29 million are blind, with best corrected visual acuity equal to or worse than 20/200, or visual field extent less than 20 degrees in diameter.1 Visual impairment and blindness are associated with negative physical and mental effects. Numerous studies have shown an association between visual impairment and a reduced quality of life, difficulties performing activities of daily living, and higher rates of depression.2-6 Furthermore, visual impairment and blindness are a major economic burden, costing an estimated $16.2 billion in direct medical costs and $8 billion in productivity losses for adults in the United States.7 Due to the impact of visual impairment on quality of life, the economy, and health services, it is important to understand the current and future prevalence of visual impairment, blindness, and associated eye diseases. Current prevalence estimates have established disparities in vision loss among age groups, racial groups, and sex.8 The prevalence of these diseases is expected to outpace the rate of population growth due primarily to the aging population, shifting demographics, and increasing prevalence of diabetes.9 Current and future projections of visual impairment exist on a national level, but to our knowledge, there are currently very few, if any, state-based projections that delineate predictions by eye disease and demographic factors. These state-specific projections fill an important gap as states vary widely in their demographic makeup, predicted growth rate, and rate of obesity and diabetes, all of which directly affect projections for visual impairment. Specifically, states with larger African American populations, such as Georgia, will need to prepare for an increased burden of glaucoma and those faced with the growing obesity and diabetes epidemic, such as in the South, will have increased diabetic retinopathy10. Because of the racial demographics and the current and predicted high prevalence of diabetes, we expect the state of Georgia to be particularly affected by visual impairments and blindness in the future. Additionally, Georgia is demonstrating more rapid population growth than most other states and is in the top 10 fastest growing states in the country.11 This is primarily due to Georgia having a larger than average rate of birth (ranked 8th in 2018 census data) and net migration (ranked 7th)12. This paper aims to close that gap and provide approximate estimations for the state of Georgia that will enable appropriate planning and budgeting for the future. Additionally, we hope to make the case for and encourage other states to evaluate what the future of vision health looks like for their state and begin discussions on what will be needed to ensure a healthy, prospering population. We will include the current (2013) and projected future prevalence (2050) of visual impairment, blindness, primary open angle glaucoma (OAG), diabetic retinopathy (DR), cataract, age-related macular degeneration (AMD), and refractive error for the state of Georgia in this paper.

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A Vision for Georgia: Prevalence of Disease in 2050

Methods Definitions Both visual impairment and blindness are defined using the US definitions. Specifically, visual impairment is defined as best corrected visual acuity worse than 20/40 but better than 20/200 in the better-seeing eye, and blindness is defined as best corrected visual acuity in the better-seeing eye of worse than or equal to 20/200, or a visual field extent of less than 20 degrees in diameter. For disease prevalence the definition included a single person meeting the diagnostic criteria in either eye. Refractive error is classified as myopia or hyperopia, including both corrected and uncorrected; myopia is defined as a spherical equivalent of -1.0 D or less, and hyperopia is defined as a spherical equivalent of +3.0 D or more. AMD is defined as either non-exudative AMD with geographic atrophy or exudative AMD with neovascularization. Prevalence estimates of cataract include a definition of cortical cataract that affect 25% or more of the lens, posterior sub-capsular cataract of 1 mm or larger, or nuclear cataract that is equal to or greater than the second highest grade in the utilized grading system (in the Lens Opacities Classification System II, commonly a grade of NII or NIII). Prevalence estimates of diabetic retinopathy include retinopathy of grade 14 or higher on the ETDRS final scale based on fundus photographs, involving macular edema, definite non-proliferative retinopathy, or proliferative changes. Primary open angle glaucoma was defined as cases that had optic nerve damage and/or reproducible visual field loss.1 Statistical methods To obtain projetions of an eye disease’s prevalence through 2050, the following statistical modelling strategy and methods were used: (1) We needed to obtain the joint race-gender-age distribution of the population through 2050; (2) For each specifc agerace-gender demographic, we needed to estimate/have the prevalence rate of the given eye disease for that specific group. For step 1, we modelled the joint race-gender-age distribution of population as a product of the marginal distribution of age with the joint race-gender distribution of the population. The marginal distribution of age in the population was based on the Georgia state population projections and demographic data as described below. And the joint race-gender distribution of population was based on the current population demographic stratifications. Population projections and demographic data were obtained from the Georgia Governor’s Office of Planning and Budget13. Per the Governor’s website the current population data comes from the U.S. Census and the projections were “prepared using the standard cohort component demographic methodology, relying upon recent historical fertility, migration, and age data”13. We used the population projections to 2050 stratified by age group to account for the aging population and applied the current population demographic stratifications to these projections, under the assumption that the race and gender stratifications will not significantly change between now and 2050

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A Vision for Georgia: Prevalence of Disease in 2050

in Georgia and that aging will affect different races and genders to the same extent. This assumption was necessary given the limitations of data available and unknown migration patterns. For step two we used Prevent Blindness America prevalence value for each eye disease within a specific age, race, and gender demographic to calculate the projected prevalence of visual impairment, blindness, open angle glaucoma, cataract, and age related macular degeneration, using the assumption that within each demographic category, the incidence of each disease would remain stable and not significantly change between now and 2050.14 To compare our results to the overall US data, we used the published data from Prevent Blindness America’s “The Future of Vision” report.15 For diabetic retinopathy: We used the 2017 International Diabetes Federation Atlas on the projected prevalence of diabetes (2015 and 2040) and applied this to our Georgia census data. We then used 2008 CDC data on the prevalence of diabetic retinopathy among those with diabetes, and applied age-specific diabetic retinopathy prevalence values to the corresponding age groups among those with diabetes in 2015 and 2040.16 These methods assume that the prevalence of diabetic retinopathy among those with diabetes would not significantly change between now and 2050. This captures the future prevalence of DR while accounting for the increase in diabetes prevalence as well as the aging population. Results Current estimates for the burden of eye disease in the state of Georgia in 2013 include 71,000 people with visual impairment, with an additional 32,000 blind individuals. The most common cause of visual impairment is presence of, ie both corrected and uncorrected, refractive error, affecting over 1.4 million people. Cataract is the next most common cause, with nearly 677,000 cases in the state in 2013. Glaucoma and AMD affect 100,000 and 43,000 people, respectively. Georgia’s Governer’s Office anticipates a 47% increase in the population by year 2050. In Georgia in 2050, there will be a projected 226,000 visually impaired persons, and nearly 100,000 will be blind. 65% of those who are visually impaired or blind will be aged 80 or older. There will be 1.7 million cases of cataract, and 2.3 million with refractive error. Additionally, there will be over 250,000 cases of glaucoma, and 117,000 cases of AMD. Full results for the projected cases of visual impairment, blindness, and its major causes are outlined in Table 1. Figure 1 demonstrates the growth rate that is expected for all causes of visual impairment in Georgia. There will be over a 280% projected increase in visual impairment in those 80 and older by 2050, and a 211% increase in those 70-79 years of age.

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A Vision for Georgia: Prevalence of Disease in 2050

To highlight the additional burden of visual impairment, blindness, and its causes that Georgia can expect in 2050, Figure 2 demonstrates the additional cases of each eye disease, subtracting current estimated cases (2013) from the predicted cases in 2050. Diabetic Retinopathy The total caseload of DR in adults age 40 and older is expected to increase from 287,000 to 435,000 between 2015 and 2040, approximately a 52% growth rate, compared to a calculated 45% growth rate for the general US population over the same time period.15 Table 2. Comparing Georgia’s growth in disease prevalence to USA projections A comparison of Georgia’s disease projections (as listed above) to the projections published by Prevent Blindness America for the overall USA population to 2050 is shown in Figure 3. Georgia’s projections used the same stratification-specific prevalence values, but were applied to the projected population growth specific for Georgia. A greater increase in every eye disease is expected in Georgia as compared to the USA projections.

Discussion Our forecasts for the future prevalence of visual impairment, blindness, and its major causes show a striking growth by the year 2050 in Georgia. The growth rate of visual impairment between 2013 and 2050 is nearly 220% for adults age 40 and older in the state of Georgia. There will be over 324,000 people with visual impairment or blindness in Georgia in 2050. These striking results demonstrate the significant need for eye care services that is expected over the next 30 years. As the population ages and the needs for eye care expand, our access to care and care delivery methods must be able to adjust to meet these needs. Research has shown that an investment in eye care services over the last 20 years has resulted in a decrease in age-standardised prevalences for most eye diseases despite the increase in raw number of cases.17,18 The additional burden of cataract is the most striking volume of additional eye disease. There will be a total of over 1.7 million cases of cataract, which is over 1 million more cases than what Georgia is facing today. Current estimates of the number of eye care providers in the state of Georgia today approximates that there are 970 eye care offices, 272 of which are ophthalmology offices.19 If all patients with cataract desire surgical consultations, these 272 offices each must accommodate on average 1,250 cataract patients a year for 5 years to address the projected need. Of note this does not include additional cases in those 5 years which can be expected nor does it take into consideration that not all ophthalmologists perform cataract surgery. This number would likely overwhelm the current amount and distribution of eye care offices and providers in Georgia.

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A Vision for Georgia: Prevalence of Disease in 2050

Our projections show a higher growth rate than those published in The Future of Vision report by Prevent Blindness America. Prevent Blindness America reported a projected growth rate for visual impairment of 151%, and while this is still a remarkable growth rate, it is notably smaller than our projected 219% growth rate. The additional growth in the state of Georgia as compared to the US as a whole is multifactorial, but among the strongest reasons is that Georgia is among the top ten fastest growing states in the country, and thus will be more greatly affected by the additional burden in eye disease.11 The growth rate of visual impairment between 2013 and 2050 is more striking in the older demographics, with those aged 80 and older having a predicted 350% increase in visual impairment. Because our methods assume a constant prevalence of visual impairment within each age stratification, the additional cases in the elderly is a reflection of the aging population. This is not unique to Georgia but does exemplify a strong need for increased eye care services to meet the growing demand. Racial demographic differences between Georgia and the US also affect these projections and contribute to variations in data. Georgia has a higher proportion of black Americans than the average state in the US.20 Certain eye diseases are affected by race; most notably, the prevalence of OAG is higher across all age groups among blacks than any other racial groups. On average, 2.2% of whites aged 40 and above have glaucoma, while 5.7% of blacks in that same age group have glaucoma.14 Because of Georgia’s current racial demographics, we expect that Georgia will be more significantly impacted by OAG than some other states in the US. This is reflected in the estimated growth rate of OAG in Georgia, which is over 153%, in comparison to the average US growth rate, which is 103%. Unlike cataract, OAG has an earlier age of onset and requires frequent evaluation and follow up which will quickly overburden the system. We also highlighted the current and future prevalence of diabetic retinopathy. The predicted increase in diabetes, caused in part by the obesity epidemic, is expected to drive up the prevalence of diabetic retinopathy across all age groups. All diabetics are recommended to have yearly eye exams to evaluate for the presence of diabetic retinopathy. The burden of diabetic retinopathy is predicted to grow to over 435,000 cases in Georgia by 2040. Patients with diabetic retinopathy need at least yearly evaluations and thus need to utilize a significant share of available eye care services. Furthermore, a proportion of these patients will need monthly exams for visionthreatening diabetic retinopathy, estimated at 8% of all diabetics.21 This will likely result in well over 500,000 visits per year in the state of Georgia for diabetic retinopathy care alone. Currently, there are 970 eye care offices in the state of Georgia, 28% of which are ophthalmology offices. If all 970 current offices have the capacity to care for diabetic retinopathy patients, each office would still have to see at least 515 diabetic retinopathy patients per year in 2050.

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A Vision for Georgia: Prevalence of Disease in 2050

There are a number of limitations in this report. Our projections required several assumptions to be made surrounding our data. We assumed that the rate of visual impairment, blindness, OAG, cataract, AMD, DR, and refractive error would stay constant across all groups. However, shifts in access to or utilization of medical care and changes in technology could impact the prevalence of vision problems across subgroups. Additionally, this study assumes a static work force in the state of Georgia in some of our conclusions. While the work force is expected to increase we did not feel that it would be a statistically significant amount as many eye care providers are also expected to retire. Furthermore, our projections do not capture the shifting racial demographics that are predicted in the state of Georgia. Our projections assume that the current racial demographics will stay constant through 2050. However, these projections likely underestimate the burden of visual impairment and its causes, particularly glaucoma, because the black population is predicted to be growing in the state of Georgia over the next 30 years, not staying constant.22 Despite these limitations, these estimates provide guidance to predict the public health burden of eye disease and plan for future needs. The aging population and racial demographics impact projections for future eye disease burden, causing state-level projections to vary from national levels. These results are critical to understand and utilize in future planning for eye care delivery in the state of Georgia, as it is for all states across the U.S.. There is not “one size fits all” model for eye care. As the demand for eye services increases, states must have individualized projections to enable tailored preparations for service delivery, educational campaigns, and advocacy that reflect the specific needs of each individual state.

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A Vision for Georgia: Prevalence of Disease in 2050

Acknowledgements

A: The study was partially supported by an unrestricted grant from Research to Prevent Blindness to the Emory University Department of Ophthalmology B: Jacquelyn O’Banion: no financial disclosures Elaine Kelly: no financial disclosures Qing Wen: Danny Haddad: Orbis International C: Other Acknowledgements: none

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A Vision for Georgia: Prevalence of Disease in 2050

References 1. 2. 3.

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Friedman DS. Vision Problems in the U.S. In. Vol 2019. Fifth Edition ed. Prevent Blindness America. 2012. Renaud J, Bedard E. Depression in the elderly with visual impairment and its association with quality of life. Clin Interv Aging. 2013;8:931-943. Li Y, Crews JE, Elam-Evans LD, et al. Visual impairment and health-related quality of life among elderly adults with age-related eye diseases. Qual Life Res. 2011;20(6):845-852. Khil L, Wellmann J, Berger K. Impact of combined sensory impairments on healthrelated quality of life. Qual Life Res. 2015;24(9):2099-2103. Zhang X, Bullard KM, Cotch MF, et al. Association between depression and functional vision loss in persons 20 years of age or older in the United States, NHANES 20052008. JAMA Ophthalmol. 2013;131(5):573-581. Crews JE, Campbell VA. Vision impairment and hearing loss among communitydwelling older Americans: implications for health and functioning. Am J Public Health. 2004;94(5):823-829. Rein DB, Zhang P, Wirth KE, et al. The economic burden of major adult visual disorders in the United States. Arch Ophthalmol. 2006;124(12):1754-1760. Varma R, Vajaranant TS, Burkemper B, et al. Visual Impairment and Blindness in Adults in the United States: Demographic and Geographic Variations From 2015 to 2050. JAMA Ophthalmol. 2016;134(7):802-809. Boyle JP, Thompson TJ, Gregg EW, Barker LE, Williamson DF. Projection of the year 2050 burden of diabetes in the US adult population: dynamic modeling of incidence, mortality, and prediabetes prevalence. Popul Health Metr. 2010;8:29. Prevention CfDCa. National Diabetes Statistics Report, 2017. In: Services USDoHaH, ed 2017. 2018 National and State Population Estimates. In. US Census Bureau 2018. Bureau USC. 2018 National and State Population Estimates. https://www.census.gov/newsroom/press-kits/2018/pop-estimates-nationalstate.html. Published 2018. Accessed August 20, 2019. Census Data and Population Projections. https://opb.georgia.gov/. Accessed June 1 2016. Prevent Blindness America Data Downloads: Vision Problems in the US. Accessed June 1 2016. Wittenborn JR, David. The Future of Vision: Forecasting the Prevalence and Costs of Vision Problems. Prevent Blindness 2014. US Diabetes Surveillance System - GIS and CDC. 2016. Bourne RRA, Flaxman SR, Braithwaite T, et al. Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis. The Lancet Glob health. 2017;5(9):e888-e897. Bourne RRA, Jonas JB, Bron AM, et al. Prevalence and causes of vision loss in highincome countries and in Eastern and Central Europe in 2015: magnitude, temporal trends and projections. Br J Ophthalmol. 2018;102(5):575-585.

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A Vision for Georgia: Prevalence of Disease in 2050

19. 20.

21. 22.

Williams A. Through the Lens of Spacial Access to Care: The State of Georgia’s Vision: Environmental Health, Emory University Rollins School of Public Health; 2019. Race and Ethnicity in Georgia. US Census Bureau. https://statisticalatlas.com/state/Georgia/Race-and-Ethnicity. Published 2018. Accessed August 1 2019. Eye Disease Prevalence Group. The prevalence of diabetic retinopathy among adults in the United States. Arch Ophthalmol. 2004;122:552-563. Datar S. Map: Demographic patterns in every Georgia county, 1990-2050. https://www.ajc.com/news/state--regional/map-watch-georgia-racial-and-ethnicchanges-unfold/UWVTVqmkLK9wU9DC6jv6KL/. Published 2019. Accessed August 1 2019.

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A Vision for Georgia: Prevalence of Disease in 2050

Captions: Table 1: Projected Cases of Eye Disease in Georgia in 2050 exemplifying the number of expected cases of blindness, vision impairment, Age Related Macular Degeneration, glaucoma and cataract based on the expected population growth and demographics of Georgia in 2050 Figure 1: Growth rates of all causes of visual impairment by age group (data indexed to 2013). This graph visualizes the increase in vision loss by age group that is expected by year 2050. The significant burden of disease in the 70-79 years and 80+years age group is most noticeable. Figure 2: Additional burden of Eye Disease. This graph shows the increase in case load by subtracting the current number of cases (in 2013) from the expected (in 2050) which highlights the increased burden in addition to the current backlog or caseload. Table 2: Current and Projected Cases of Diabetic Retinopathy which is expected to nearly double by 2050. Standard deviations are given within parenthesis for the projected data. Figure 3: Comparing Georgia’s growth to Prevent Blindness America USA Projections. Comparing the rate of growth ([projected number of cases – current number of cases]/current number of cases * 100%) of disease in the Georgia population to that of the overall US population allows providers to see how eye care in Georgia will differ from the general population and allow providers to plan services accordingly.

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Table 1: Projected Cases of Eye Disease in Georgia in 2050

Age Group

Blindness (SD)

Visual Impairment (SD)

AMD (SD)

Glaucoma (SD)

Cataract (SD)

40-49 50-59

2,553 (50) 4,270 (65)

3,037 (55) 7,001 (83)

N/A 9,128 (95)

15,694 (125) 28,312 (167)

60-69

8,750 (93)

19,277 (138)

14,183 (119)

48,745 (216)

70-79

18,603 (135)

50,483 (220)

26,626 (161)

69,612 (255)

80+

64,318 (244)

67,353 (245)

91,683 (288)

Total

98,494 (306)

146,601 (353) 226,350 (449)

117,291 (330)

254,047 (488)

46,630 (213) 144,410 (364) 346,616 (523) 556,012 (571) 619,940 (483) 1,713,608 (1,006)

Table 2: Current and Projected Cases of Diabetic Retinopathy Age (years) Year

Sex

40-49

50-64

65-74

75+

2015

Women

22,847

60,492

37,440

11,525

Men

33,597

70,595

39,050

11,605

Total

56,444

131,088

76,490

23,130

287,152

Women

26,895 (138) 39,780 (154) 66,675 (207)

78,285 (228) 94,262 (244) 172,547 (335)

66,270 29,368 (204) (136) 70,051(215) 30,224 (144) 136,321 59,592 (297) (198)

435,135 (531)

2040

Men Total

Total

Figure 1: Growth rates of all causes of visual impairment by age group (data indexed to 2013)

Growth Rates of Visual Impairment in Georgia 300%

80+ 250%

70-79 200%

150%

60-69 100%

50-59 50%

40-49

0% 2013

2015

2020

2025

2030

2035

2040

2045

2050

Figure 2: Additional burden of Eye Disease

Additional Burden of Eye Disease (2050-2013) 12,00,000 10,00,000 8,00,000 6,00,000 4,00,000 2,00,000 Visual Impairment

Blindness

OAG

AMD

Cataract

Figure 3: Comparing Georgia’s growth to Prevent Blindness America USA Projections

Comparing Georgia's Growth to USA Projections 250% 200% 150% 100% 50% 0% Visual impairment

Blindness

OAG Georgia

USA

AMD

Cataract