PURPOSE. To examine projections of age-related eye diseases in the United States for health care planning. METHODS. Review of published scientific articles, census data, and unpublished research findings. RESULTS. The numbers of cases of all age-related eye diseases are expected to rise in the coming years. These projections are primarily based upon population projections, but give little consideration to changes in health behaviors, racial/ethnic differences, environmental exposures, and changes in health care practices that may influence estimates of costs of actual health care burden. CONCLUSIONS. Ongoing monitoring of trends in eye disease distribution is needed rather than projections based on old data that may be inadequate for generating reliable prediction models. There is a perpetual need to train new researchers with expertise in epidemiology, as the exigency for current prevalence estimates is crucial to maximize optimal visual health in the population

Barbara E K Klein

Ronald Klein

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Special Issue
Projected Prevalences of Age-Related Eye Diseases
Barbara E. K. Klein and Ronald Klein
Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison,
Wisconsin
Correspondence: Barbara E. K.
Klein, Department of Ophthalmolo-
gy and Visual Sciences, University of
Wisconsin School of Medicine and
Public Health, 610 N. Walnut Street,
409 WARF, Madison, WI 53726;
kleinb@epi.ophth.wisc.edu.
Submitted: July 9, 2013
Accepted: July 12, 2013
Citation: Klein BEK, Klein R. Projected
prevalences of age-related eye diseas-
es. Invest Ophthalmol Vis Sci.
2013;54:ORSF14–ORSF17.
DOI: 10.1167/iovs.13-12782
PURPOSE. To examine projections of age-related eye diseases in the United States for health
care planning.
METHODS. Review of published scientific articles, census data, and unpublished research
findings.
RESULTS. The numbers of cases of all age-related eye diseases are expected to rise in the
coming years. These projections are primarily based upon population projections, but give
little consideration to changes in health behaviors, racial/ethnic differences, environmental
exposures, and changes in health care practices that may influence estimates of costs of actual
health care burden.
CONCLUSIONS. Ongoing monitoring of trends in eye disease distribution is needed rather than
projections based on old data that may be inadequate for generating reliable prediction
models. There is a perpetual need to train new researchers with expertise in epidemiology, as
the exigency for current prevalence estimates is crucial to maximize optimal visual health in
the population.
Keywords: age-related eye diseases, prevalence, review
The prevalence of most eye diseases increases with age invirtually all populations. The Eye Diseases Prevalence
Research Group (EDPRG) reported on data from ten different
prevalence studies to estimate the prevalence of visual
impairment and several specific eye diseases in persons 40
years of age or older to estimate the burden of these conditions
in the United States (US) in 2000.1–6 These data and information
from the National Health and Nutrition Examination Survey
(NHANES) and other sources are compiled in another
publication in this volume. In order to plan for future eye
healthcare needs, projections for the future are desirable. It is
the purpose of this paper to briefly describe current
projections and potential limitations thereof.
MATERIALS AND METHODS
Study Population
Population projections to the year 2020 are from published
projections from the EDPRG. For POAG, the projections are
supplemented by information from 2011.7
Measurements
Estimates of prevalence were based on protocols that varied
among the studies. Errors and systematic differences among
studies are incorporated in the projections because there were
no attempts to adjust prevalence data to uniform criteria for
diagnostic labeling.
An example of the varying criteria for diagnostic labeling
was given for glaucoma. In the EDPRG, six different sets of
criteria were given for the studies.3 Some included disc
photography, cutpoints varied for cup/disc diagnostic crite-
ria, some studies included a cutpoint for IOP, each used
different techniques to assess visual fields, and some studies
had subjective evaluation of components of glaucoma-related
abnormalities, while others used a uniform set of criteria.
Statistical Analysis
The projected estimates from the EDPRG of the numbers and
percentages of persons with the conditions were generated by
applying the age, sex, and race/ethnicity of the prevalence
data estimated for 2000 to projected middle series population
projections for 2020.1–6 For the POAG estimates, Vajaranant
and colleagues used prevalence estimates from the Baltimore
Eye Survey, the Los Angeles Latino Eye Study, and the Tanjong
Pagar Survey and applied these to the US Census population
projections from 2011 to 2050 using middle series.7 Census
population projections for 2000 to 2050 as well as methods
for the 2012 updated projections were obtained from the US
Census Bureau.8,9 Figures in this paper are reproduced from
reports from the US Census Bureau8,10; the Table is a
summary of projections that appeared in papers from the
EDPRG.1–6
RESULTS
Predictions of disease prevalence depend upon projections
of population changes by age and sex to the same date as the
predictions aim for. For example, Figure 1 describes the
middle series projections of the population by age and sex
for 2012 to 2060 as calculated by the US Census Bureau.
The EDPRG projected prevalences of age-related eye
diseases and visual functions from the year 2000 to 2020
based on projections of the US population to 2020 (Table).
The estimated number of cases of each disorder was projected
to increase over the 20-year period. They made the
Copyright 2013 The Association for Research in Vision and Ophthalmology, Inc.
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assumption that prevalence would remain the same; the
projected increase in number is a reflection of the increase in
the population size. However, projections should also account
for shifting demographics of the population, as these may
affect disease estimates. The US Census Bureau provided
estimates by region of origin of foreign-born immigrants (Fig.
2).
The US Census Bureau projected that the non-Hispanic,
white population will peak in 2024 and then fall by nearly 20.6
million to approximately 179 million by 2060, while the
Hispanic population will increase to approximately 128.8
million, the black population will increase to approximately
61.8 million, and the Asian population will increase to
approximately 34.4 million.11 Members of other racial/ethnic
groups including American Indians, Alaskan Natives, Native
Hawaiians, and other Pacific Islanders as well as those who
identify themselves as being of two or more races/ethnicities
will also increase. The older population will still be primarily
non-Hispanic white in 2060 but this will change in subsequent
years as the increasing numbers of persons of other races/
ethnicities age.
Attempting to adjust for racial/ethnic shifts in demography,
Vajaranant and colleagues7 projected the burden of POAG in
2050 based on the estimated prevalence in 2011. Their
assumption was that more recent population projections
accounting for shifts in race/ethnicity, especially for Hispanics
and Asians, would improve upon the estimates made by the
EDPRG. They estimated that there were 2.71 million persons
with POAG in 2011 and that this number would increase to
7.32 million by 2050. However, population projections tend to
be imperfect and the longer the time period in the forecast,
the less accurate it tends to be.12 A comparison of US
population projections made in 2008 and again in 2012 to the
year 2050 illustrates this problem (Fig. 3). The estimated
population projections differ by nearly 10%. Those data will be
reflected in different predictions of estimates of disease
prevalence.
There are other factors that predictions based solely on
projected differences in population by demographic changes
do not account for. There are temporal changes in the
distribution of risk factors (e.g., changes in care of persons
with diabetes, increasingly frequent cataract surgery,13,14
changes in socioeconomic status,15 access to care,16 and
changes in environmental exposures, such as exposure to UV-
B light).17 In addition, there appear to be temporal patterns in
disease incidence, which are also likely to affect prevalence in
FIGURE 1. Middle series projections of the population of the US by age and sex, 2012 to 2060 (in millions).8
TABLE. Eye Diseases Prevalence Research Group1–6 Estimates of Age-
Related Eye Disease Prevalences in 2000 and Projections to 2020 in
Persons Aged 40 Years and Older
Eye Disease
2000 2020
N in Millions (%) N in Millions
Cataract* 20.5 (17.2) 30.1
Pseudophakia† 6.1 (5.1) 9.5
Diabetic retinopathy 4.1 (3.4) 6.1
Vision-threatening diabetic
retinopathy 0.9 (0.8) 1.4
Open-angle glaucoma 2.2 (1.9) 3.4
Late age-related macular
degeneration 1.8 (1.5) 3.0
Large drusen 7.3 (6.1) 13.7
Blindness 0.9 (0.8) 1.6
Low vision 2.4 (2.0) 3.9
* Omits Mexican Americans.
† Includes Mexican Americans.
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the future. For example, Klein and colleagues18 found a
decrease in early AMD in more recent birth cohorts, which to
date is not known to reflect decreases in risk factors.
DISCUSSION
Current projections of eye disease prevalence have been based
largely on data that were collected many years ago and are
restricted to a few eye conditions that are considered to be
responsible for either visual loss (visual acuity poorer than 20/
40 in the better seeing eye) or legal blindness (visual acuity
poorer than 20/200 in the better seeing eye). These projections
have been made for at best a handful of eye conditions. There
are no known population projections for prevalence of dry eye,
retinal vein occlusions, or many corneal conditions, which
seem to be as prevalent as those for which projections have
FIGURE 2. Middle series projections of foreign-born immigration to the US by sending region: 2012 to 2060 (in thousands).8
FIGURE 3. Projected population of the US: 2012 and 2050.10
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been made. These conditions should be considered when
projecting disability from and remediation of age-related eye
conditions.
Accurate estimates of prevalence and projections for future
health care needs depend upon inclusion of all subgroups in
the population. This implies systematic inclusion of samples of
all persons including those currently undercounted and
underserved. Access to care is likely to be improved by the
Patient Protection and Affordable Care Act and the Health Care
and Education Reconciliation Act. In addition, information
about such improved access as well as education about the
benefits of using such care needs to be implemented.
In summary, projections of prevalence are critical for
planning for preventive and health care services with implica-
tions for function, quality of life, and costs; accurate projections
are difficult to make and should be time-limited; every effort
must be made to consider factors that the census does and any
important known risk and preventive factors as well as
temporal changes in them; frequent reassessment of outcomes
and risk/protective factors is essential; and funding and
encouragement for training of ocular epidemiologists is
imperative to optimize planning for public health priorities to
prevent or diminish the toll of age-related eye disease.
Acknowledgments
Supported by grants from the National Institutes of Health
(EY06594 and EY016379) as well as an unrestricted grant from
Research to Prevent Blindness, New York, New York.
Disclosure: B.E.K. Klein, None; R. Klein, None
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Projected Prevalences of Age-Related Eye Diseases

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Projected Prevalences of Age-Related Eye Diseases

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