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To evaluate the personal and community burdens of uncorrected presbyopia. We used multiple population-based surveys to estimate the global presbyopia prevalence, the spectacle coverage rate for presbyopia, and the community perception of vision impairment caused by uncorrected presbyopia. For planning purposes, the data were extrapolated for the future using population projections extracted from the International Data Base of the US Census Bureau. It is estimated that there were 1.04 billion people globally with presbyopia in 2005, 517 million of whom had no spectacles or inadequate spectacles. Of these, 410 million were prevented from performing near tasks in the way they required. Vision impairment from uncorrected presbyopia predominantly exists (94%) in the developing world. Uncorrected presbyopia causes widespread, avoidable vision impairment throughout the world. Alleviation of this problem requires a substantial increase in the number of personnel trained to deliver appropriate eye care together with the establishment of sustainable, affordable spectacle delivery systems in developing countries. In addition, given that people with presbyopia are at higher risk for permanently sight-threatening conditions such as glaucoma and diabetic eye disease, primary eye care should include refraction services as well as detection and appropriate referral for these and other such conditions.
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EPIDEMIOLOGY
Global Vision Impairment
Due to Uncorrected Presbyopia
Brien A. Holden, PhD, DSc; Timothy R. Fricke, MScOptom; S. May Ho, PhD; Reg Wong, MBA;
Gerhard Schlenther, MPH; Sonja Cronje´, MPhil(Optom); Anthea Burnett, BSc(Hons);
Eric Papas, PhD; Kovin S. Naidoo, OD, MPH; Kevin D. Frick, PhD
Objectives:To evaluate the personal and community
burdens of uncorrected presbyopia.
Methods:We used multiple population-based surveys to
estimate the global presbyopia prevalence, the spectacle cov-
erage rate for presbyopia, and the community perception
of vision impairment caused by uncorrected presbyopia.
For planning purposes, the data were extrapolated for the
future using population projections extracted from the In-
ternational Data Base of the US Census Bureau.
Results:It is estimated that there were 1.04 billion people
globally with presbyopia in 2005, 517 million of whom
had no spectacles or inadequate spectacles. Of these, 410
million were prevented from performing near tasks in the
way they required. Vision impairment from uncor-
rected presbyopia predominantly exists (94%) in the de-
veloping world.
Conclusions:Uncorrected presbyopia causes wide-
spread, avoidable vision impairment throughout the world.
Alleviation of this problem requires a substantial increase
in the number of personnel trained to deliver appropriate
eye care together with the establishment of sustainable, af-
fordable spectacle delivery systems in developing coun-
tries. In addition, given that people with presbyopia are at
higher risk for permanently sight-threatening conditions
such as glaucoma and diabetic eye disease, primary eye care
should include refraction services as well as detection and
appropriate referral for these and other such conditions.
Arch Ophthalmol. 2008;126(12):1731-1739
UNCORRECTED DISTANCE
refractive error is the
most common cause of
vision impairment and
the second most com-
mon cause of blindness in the world.1-4 Al-
though presbyopia creates refractive er-
ror affecting the near vision of older
people,5it is not included in the World
Health Organization reported prevalence
of uncorrected refractive error.4,6 How-
ever, the combination of the high preva-
lence in older adults and the low rates of
spectacle access in some communities
means that presbyopia has the potential to
cause a global burden of vision loss wor-
thy of attention.
Presbyopia is caused by age-related elas-
ticity changes in the crystalline lens and
its capsule.5To understand the progres-
sion, consider that the average 12-year-
old European child can accommodate by
12 diopters (D), allowing a nearest point
of clear vision of about 8 cm.7The aver-
age 48-year-old European adult can ac-
commodate by only 3 D, allowing a near-
est point of clear vision of about 33 cm.7
The average 60-year-old European adult
has minimal accommodation and relies on
depth of focus or artificial assistance such
as spectacles to enable clear and comfort-
able near vision.5,7 The exact age that near
vision spectacles are required depends on
a range of factors such as individual varia-
tion in accommodative ability,8distance
refraction,9,10 climate,11-15 geographic lo-
cation,12,16,17 demands and expecta-
tions,18 sex,17-21 and ethnicity.22-27 It has
been argued that studies of factors affect-
ing presbyopia are prone to the effects of
confounding variables,16,28 but there does
seem to be general acceptance of earlier
onset in people with higher melanin lev-
els in equatorial regions.
Although known physiology and popu-
lation demographics suggest that presby-
opia is common or nearly universal in
people older than 65 years,5,7 direct esti-
mates of prevalence are rare. This article pro-
vides an estimate of the global prevalence
of presbyopia by applying the results of a
systematic review of published population-
based surveys to population projections.
The total number of people with pres-
byopia is primarily of interest as a precur-
sor to the figures of greatest public health
Author Affiliations:
International Centre for Eyecare
Education (Drs Holden, Ho,
and Naidoo, Messrs Fricke,
Wong, and Schlenther, and
Mss Cronje´ and Burnett),
Institute for Eye Research
(Drs Holden and Papas and
Mr Wong), Vision Cooperative
Research Centre (Drs Holden
and Papas), and the School of
Optometry and Vision Science,
University of New South Wales
(Drs Holden and Papas),
Sydney, New South Wales,
Australia; Africa Vision
Research Institute, University of
KwaZulu-Natal, Durban,
KwaZulu-Natal, South Africa
(Dr Naidoo); and Johns
Hopkins Bloomberg School of
Public Health, Baltimore,
Maryland (Dr Frick).
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interest: the number of people with impaired vision due
to uncorrected or undercorrected presbyopia and the effect
on their lives. In the developed world, distance refrac-
tive errors and presbyopia are corrected with readily avail-
able spectacles, leaving the perception that uncorrected
refractive error does not create a significant sociomedi-
cal problem.15,29 However, underserviced areas of the world
have high levels of uncorrected and undercorrected dis-
tance refractive error,3and anecdotal observations sug-
gest that it is likely to be as bad for near vision impair-
ment. Access to spectacles in developing countries is
limited by insufficient numbers of health care profes-
sionals able to perform relevant eye examinations, a lack
of available, affordable spectacles, and a lack of ad-
equate public health support structures to help people
obtain spectacles.17,18,30-32 The worldwide effect of uncor-
rected presbyopia is determined by combining preva-
lence figures with spectacle coverage rates.
METHODS
POPULATION PROJECTIONS
AND CLASSIFICATIONS
The population projections used to estimate presbyopia preva-
lence and burden were extracted from the International Data
Base, a computerized database containing statistical tables of
demographic data for 228 countries and areas of the world pub-
lished by the US Census Bureau.33 The figures were obtained
from the August 24, 2006, release notes, which were current
at the time of writing. The International Data Base combines
data from country sources (especially censuses and surveys)
with the US Census Bureau’s International Programs Center es-
timates and projections to provide information dating back as
far as 1950 and projections as far forward as 2050.
Economic development classifications used in the estima-
tion of burden were taken from the Population Database
(2006 revision) published by the Population Division of the
United Nations Department of Economics and Social Affairs.34
The United Nations has updated the Population Database
since we calculated burden; however, the changes, including
the graduation of Cape Verde (population, 570 000) from
least developed to less developed, were too minor to alter the
calculation.
LITERATURE SEARCH STRATEGY
The prevalence of presbyopia, the prevalence of uncorrected
or undercorrected presbyopia, and the effect of uncorrected or
undercorrected presbyopia on quality of life were assessed by
searching published population-based surveys using the guide-
lines for reporting meta-analyses suggested by the Meta-
analysis of Observational Studies in Epidemiology Group.35
STUDIES AND DATABASES SEARCHED
The PubMed literature database (National Library of Medi-
cine, initially accessed on July 9, 2007, and repeated on Octo-
ber 3, 2007) was searched for publications from January 1987
to September 2007 using the following medical subject head-
ing terms defined by the National Library of Medicine to en-
sure repeatability of the search: “presbyopia AND epidemiol-
ogy,” “QALY AND vision,” and “cost-utility AND vision.” The
search was performed on all available articles regardless of the
original language of publication. The aim of the literature search
was to locate relevant articles including the prevalence of pres-
byopia, the rate of correction or noncorrection of presbyopia,
methods of measuring near vision, the type of presbyopia mea-
sured, the effect of presbyopic vision impairment on the qual-
ity of life, and the net benefit of correcting presbyopia. The search
yielded 95 articles. The abstract of each publication was re-
viewed, and articles that were population-based surveys and
included 1 or more measurements of near vision, the preva-
lence of presbyopia, the prevalence of spectacle wear for pres-
byopia, the relevant quality-of-life findings, or a cost-utility analy-
sis were obtained from the journals. Two articles from the
PubMed search that were in a language other than English were
assessed on the basis of their English abstracts. One article was
not assessed as there was no English abstract available.36 No
additional articles on population-based surveys of presbyopia
published from 1987 onward were found in the reference lists
of the articles located through the PubMed search.
The following exclusion criteria were applied to the popu-
lation-based surveys on presbyopia: (1) participating sample
size of less than 1000; (2) unspecified number of eligible par-
ticipants or participation rate (as this limits generalization of
the data); (3) inclusion of only very specific age groups (eg, if
a study was restricted to ages 70-75 years, which excludes most
people with presbyopia because the age at onset is generally
much younger); (4) data from a specific population that could
not be generalized to the population as a whole (eg, institu-
tionalized nursing home population or only women who have
given birth); and (5) an unspecified method for determining
that reduced near vision was due to optical defocus rather than
cataract or ocular pathological abnormalities.
PRESBYOPIA DEFINITIONS
Two different presbyopia definitions were used in the articles
we found using these search methods. Functional presbyopia
is defined as needing a significant optical correction added to
the presenting distance refractive correction to achieve a near
visual acuity criterion (1 line of acuity improvement in one
case, J1 print in another, and N8 print in the other).18,21,37 Ob-
jective presbyopia is defined as needing a significant optical cor-
rection (ⱖ⫹1.00 D) added to the best distance optical correc-
tion to improve near vision to a near visual acuity criterion of
N8.17 Perhaps the key epidemiological consequence of the dif-
ference between functional and objective presbyopia is that
people with low to moderate uncorrected myopia never de-
velop functional presbyopia but are likely to develop objective
presbyopia. Both definitions were accepted, but the definition
used was noted because it is expected to have an epidemio-
logical effect.
RESULTS
PREVALENCE OF PRESBYOPIA
Four population-based surveys met the inclusion crite-
ria for assessing the prevalence of presbyopia (Table 1).
Three studies were cross-sectional surveys,17,18,21 and the
fourth was a rapid assessment survey.37,38 The preva-
lence estimates vary owing to differing definitions, mea-
surement methods, measurement conditions, popula-
tion age groups studied and other population
demographics such as ethnicity and urbanization, and
climate and geographic locations.17,18,21,37,38 Each of these
sources of variation will be discussed at relevant points
in our analysis and discussion. It is worth noting at this
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point that all of the articles taken into account in our analy-
sis had a method for differentiating presbyopia (re-
duced near vision due to optical defocus) from reduced
near vision due to other causes such as cataract or ocu-
lar pathological abnormalities.
Table 1 shows that the best epidemiological studies
of presbyopia provide a wide range of prevalence esti-
mates. Prevalence from the age at onset ranged from
43.8% (Timor-Leste) to 93.4% (India). The low preva-
lence of functional presbyopia was not addressed in the
Timorese articles, which focused on the correction of
refractive error and presbyopia.37,38 It should be noted,
however, that vision measurements in the Brazilian and
Indian studies were conducted under standard indoor
illumination, whereas the Tanzanian and Timorese
studies were conducted in prevailing outdoor illumina-
tion. As illumination affects contrast, pupil size, and,
consequently, depth of focus, it could contribute much
of the variation between results. Additionally, the
higher prevalence in the Indian study can be partly at-
tributed to the use of an objective presbyopia definition
(as compared with the functional definition used by the
other 3 studies).17,18,21,37,38 The authors of the Indian
study recognized that the objective definition of presby-
opia may overstate the number of services and spec-
tacles required.17
Another 4 studies contained data on the prevalence
of presbyopia but did not meet the inclusion criteria. The
results from these studies and the reasons for exclusion
are summarized in Table 2. These extra studies in-
crease confidence that the larger population-based data
are reasonable, but they were not used in our preva-
lence estimations because of their scientific limitations.
CALCULATION OF GLOBAL PREVALENCE
The outcome of the Brazilian study (conducted in the coun-
try’s far southern temperate region with 81% of the par-
Table 1. Summary Table of Findings From Presbyopia Population Studies in Tanzania, Brazil, India, and Timor-Leste
Characteristic Tanzania18 Brazil21 India17 Timor-Leste37,38
Participants, No. 1562 3007 5587 1414
Region Africa South America Asia Asia
Ethnicity African 81% White, 19% other Indian Austronesian
Participation rate, % 83 93.2 90 96
End-point N print size N8 N4 N8 N8
Method of measuring near vision Modified near low vision
screening E chart at 40 cm
Letter chart at 37 cm Unspecified near VA chart
at 40 cm
Modified near VA chart
at unspecified distance
Prevalence of presbyopia, %
Age, y
30-39 NA 10.7 22.9 NA
40-49 50.4 47.8 92.6 43.5
50-64 68.7 86.3 NA NA
50-69 NA NA 94.6 48.1
65 72.4 92.9 NA NA
70 NA NA 88.4 32.6
Overall 61.7 54.7 69.9 43.8
Presbyopia type Objective and functional Functional Objective Functional
Assumed age at onset, ya40 45 40 40
Prevalence of presbyopia from assumed
age at onset and older, %
Objective, 61.7; functional, 58.9 83.0b93.4 43.8
Abbreviations: NA, not applicable; VA, visual acuity.
aAssumptions are based on varying reports of the effect of climate, ethnicity, geographic location, and other variables on presbyopia.8-28
bThe prevalence of presbyopia in subjects aged 40 years and older is 72.3%.
Table 2. Summary Table of Findings From Presbyopia Population Studies That Did Not Meet the Inclusion Criteria
Characteristic Nigeria39 Southwest Uganda39,40 Ghana27 Pakistan41
Participants, No. 510 182 1884 511
Age, y 18-49 13 50to70
Type of study Random survey Referred patients to eye clinic Retrospective study
of clinical records
Cross-sectional study
of non-vision-impairing
conditions
Assumed age at onset, ya40 40 40 40
Reason for exclusion from
global calculations
Too small, lack
of definitions
Too small, lack of definitions,
clinical population
Lack of definitions,
clinical population
Too small, lack
of definitions
Prevalence of presbyopia, % 83b80b82 b71.5c
aAssumptions are based on varying reports of the effect of climate, ethnicity, geographic location, and other variables on presbyopia.8-28
bFor ages 40 years and older.
cFor ages 30 years and older.
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ticipants being white) was chosen as representative of cooler
climates and a white population. Consequently, a pres-
byopia prevalence of 83.0% and an age at onset of 45 years
were used to calculate the number of people with pres-
byopia in Australia, New Zealand, North America, Eu-
rope, and western Asia.21 An age at onset of 40 years and
a functional presbyopia prevalence of 58.9% from the Tan-
zanian study were used for Africa, Latin America, the Ca-
ribbean, and the Pacific Islands.18,42 An age at onset of 40
years and a prevalence of 43.8% from the Timorese study
were used for Asia (except western Asia).37,38
These choices of representative data lead to the inter-
esting situation of using Timorese data rather than data
from Andhra Pradesh, India, for estimating the Indian
presbyopia prevalence. The result has been a far more
conservative estimate of global prevalence, but one that
we anticipate will prove more practical in reality. The con-
ventional understanding of physiology is that everyone
eventually develops objective presbyopia, and all of those
without low to moderate myopia develop functional pres-
byopia.5,7 In reality, individual variations in pupil size and,
consequently, depth of focus and accommodation abil-
ity create a difference between physiology-based expec-
tations and epidemiological findings. The low preva-
lence used for Asia provides an allowance for the high
rate of myopia in the region, which enables many of those
affected by objective presbyopia to be able to function at
near without optical correction. One study found that 32%
of Chinese adults in Singapore older than 40 years have
low myopia,43 although other studies show substantial
variation in myopia. A review of 6 large population stud-
ies covering the United States, western Europe, and Aus-
tralia found that 25.4%, 26.6%, and 16.4% of the respec-
tive populations aged 40 years or older have at least 1.00
D of myopia.44 An Indian population study showed that
around 5% of its population aged 40 to 49 years had low
myopia.45 By using the functional presbyopia preva-
lence from Timor-Leste (43.8%) rather than the objec-
tive presbyopia prevalence from Andhra Pradesh (93.4%),
we believe that we have provided a more practical esti-
mation of the number of people with vision impairment
from presbyopia.
Combining the prevalence data with the population
projections of the International Data Base gave an esti-
mate of 1.04 billion cases of functional presbyopia in 2005.
It is estimated that 67% of people (or 696 million people)
with presbyopia live in the less- and least-developed re-
gions of the world. This global prevalence of presbyopia
is predicted to increase to 1.4 billion by 2020 and to 1.8
billion by 2050. These estimates are summarized in
Table 3 and shown in the Figure.
BURDEN OF UNCORRECTED
AND UNDERCORRECTED PRESBYOPIA
Six population-based surveys met the criteria for assess-
ing the rate of correction of presbyopic vision impair-
ment. As expected, the percentage of people with pres-
Table 3. Estimate of Global Prevalence of Presbyopia
Region
Age at
Onseta
Prevalence of
Presbyopia, %
Population From Age
at Onset and Older
in Specified Year, No. in Millions
Population With Presbyopia
in Specified Year, No. in Millions
2005 2010 2020 2050 2005 2010 2020 2050
More-developed countries within regionsb
Australia and New Zealand 45 83.0 9.0 10.1 11.9 15.8 7.5 8.4 9.9 13.1
North America 45 83.0 74.8 85.2 108.4 145.1 62.1 70.7 89.9 120.5
Europe 45 83.0 299.5 315.7 338.3 341.6 248.6 262.0 280.8 283.5
Japan 40 43.8 68.7 72.0 75.9 78.0 30.1 31.5 34.2 31.1
Total 452.0 482.9 534.5 580.5 348.2 372.6 414.8 448.2
Less-developed countries within regionsb
Pacific Islands 40 58.9 1.6 1.9 2.5 5.1 0.9 1.1 1.5 3.0
Latin America and Caribbean 40 58.9 156.1 180.9 236.1 383.3 91.9 106.6 139.0 225.7
Africa 40 58.9 86.9 97.9 125.2 269.8 59.0 66.8 86.3 183.3
Eastern Asia, excluding Japan 40 43.8 505.6 593.3 669.2 714.9 221.5 259.9 293.1 313.1
South-central Asia 40 43.8 364.2 418.4 478.3 542.0 159.5 183.3 209.5 237.4
Southeastern Asia 40 43.8 133.7 156.3 179.8 205.0 58.6 68.5 78.8 89.8
Western Asia 45 83.0 35.5 42.8 51.0 60.6 29.5 35.5 42.3 50.3
Total 1283.7 1491.5 1742.1 2180.6 620.9 721.6 850.5 1102.7
Least-developed countries within regionsb
Pacific Islands 40 58.9 0.2 0.2 0.3 0.6 0.1 0.1 0.2 0.3
Latin America and Caribbean 40 58.9 1.6 1.8 2.3 5.1 1.0 1.1 1.4 3.0
Africa 40 58.9 74.5 84.3 112.1 299.9 45.6 51.7 68.8 182.6
South-central Asia 40 43.8 42.2 50.0 58.7 68.5 18.5 21.9 25.7 30.0
Southeastern Asia 40 43.8 17.6 20.4 23.6 26.8 7.7 8.9 10.3 11.7
Western Asia 45 83.0 2.4 2.9 3.4 4.0 2.0 2.4 2.8 3.3
Total 138.5 159.5 200.3 404.8 74.9 86.0 109.1 231.0
Global total 1874.2 2133.9 2476.9 3165.9 1043.9 1180.2 1374.4 1781.8
aAssumptions are based on varying reports of the effect of climate, ethnicity, geographic location, and other variables on presbyopia.8-28
bThe United Nations Department of Economics and Social Affairs classifies all countries in Europe and North America plus Australia, New Zealand, and Japan as more
developed, and all other countries are either less or least developed.34
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byopia who have adequate spectacles varies between
countries. In Tanzania, only 6% of people with presby-
opia had corrective near vision spectacles.42 In Brazil, 55%
of people with presbyopia had spectacles, but only 71%
of these corrections were adequate (ie, 39% of presby-
opic Brazilian individuals had adequate near optical
correction).21 Only 30% of people with presbyopia in In-
dia and 26% in Timor-Leste had appropriate corrective
near vision spectacles.17,37,38
In the Australian population-based study, 85% of
men and 87% of women older than 40 years wore spec-
tacles at their near vision assessment, and 98% were
able to read N8 print with those spectacles46—ie, 84%
had appropriate corrections. The Finnish study found
that 96% of individuals in a sample population older
than 30 years were able to read newsprint with their
current spectacles.47
This published evidence was used to calculate global
uncorrected or undercorrected presbyopia, matching
populations as closely as possible for geographic region
and level of development. Table 4 shows the calcula-
tion of the global percentage of people who do not have
adequate near vision spectacles. In a United Nations De-
partment of Economics and Social Affairs–defined least-
developed country, the likelihood of possessing appro-
priate near vision spectacles is only 6% to 26%. The
likelihood rises to 30% to 39% for less-developed coun-
tries and 84% to 96% for more-developed countries.
An important part of the question related to the bur-
den of uncorrected presbyopia is the significance of the
level of impairment caused by presbyopia, taking into ac-
count socioeconomic, geographic, and cultural issues.
Measures of the impairment caused by presbyopia show
that 70% of rural Tanzanian individuals, 58% of Brazil-
ian individuals, and 53% of Indian individuals with func-
tional presbyopia experience difficulty with relevant near
tasks when using their habitual spectacles.17,21,42 In more-
developed countries, the only near vision disability mea-
sure investigated by any study was whether people can
see to read. The assumption is that everyone is literate
and no other activities of daily living are generally in-
vestigated. For example, a Finnish study found that 93%
of its sample population felt capable of seeing for read-
ing, and 96% of the same sample were able to read news-
print with their current spectacles.47 This evidence was
used to estimate the global number of individuals feel-
ing disabled by uncorrected presbyopia, using local defi-
nitions of feeling disabled. Estimates are shown in
Table 5.
COMMENT
MAGNITUDE AND IMPORTANCE
OF THE PROBLEM
We estimate that there were 517 million people without
adequate correction for functional presbyopia in 2005
(Table 4). However, not every one of these people with
uncorrected or undercorrected functional presbyopia
would require a pair of spectacles for near tasks. Some
people have minimal or no near-point vision require-
ments. Using local definitions of disability, the best es-
timate of the number of individuals experiencing dis-
ability caused by uncorrected presbyopia was 410 million
people in 2005, of whom 386 million (94%) live in less-
and least-developed countries (Table 5).
Without intervention to make spectacles more acces-
sible, the global number of individuals who will have a
disability associated with uncorrected presbyopia is pre-
dicted to grow to 563 million people by 2020 (Table 5).
CAVEAT ON FUTURE PREDICTIONS
Many developments are likely to affect future predictions
of the burden of uncorrected presbyopia. Fixed demand
for and availability of spectacles have been assumed, nei-
ther of which are likely to be true. Economic develop-
ment generally brings a greater reliance on literacy and other
acuity-related near activities, which are likely to increase
the demand for near vision spectacles. Economic develop-
ment is also likely to increase the supply of and access to
spectacles. We have made no attempt to predict the influ-
ence of these factors in our estimates.
MORE STUDIES NEEDED
The studies on which we have based our global esti-
mates had the strengths of large participating sample sizes,
clearly stated participation rates, appropriate age ranges
with good spread between ages, population-based re-
cruitment, and clear methods for excluding near vision
impairment due to presbyopia from other causes such
as cataract or ocular pathological abnormalities. A more
precise estimate of the global prevalence of presbyopia
would require this quality of data from as many indi-
vidual countries as possible. This would decrease the in-
fluence of confounding factors such as ethnicity, geo-
graphic location, climate, distance refraction, visual
demand, and personal expectation. However, only a lim-
ited number of high-quality population-based studies have
been completed at this time.
The available studies were generalized as carefully as
possible based on ethnicity, location, and climate. For
example, the functional presbyopia prevalence figure of
2000
1800
1600
1400
1200
1000
800
600
400
200
0
2005 2010 2020 2050
Year
Population, No. in Millions
More-developed countries
Less- and least-developed countries
Global total
Figure. The predicted number of people with presbyopia from 2005 to 2050.
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43.8% used for Asia was generalized from the Timor-
Leste study.37,38 Even though the Timorese prevalence fig-
ure seems low, it was felt that this conservative estimate
should be used to avoid overstating the need. The alter-
native for Asia would be to use the objective presbyopia
prevalence figure of 93.4% from the Andhra Pradesh Eye
Disease Study in India.17 Although the Andhra Pradesh
study had a more thorough and robust method, use of
the objective presbyopia definition will include people
with myopia who do not have near vision impairment
and do not require spectacles for near tasks. Given the
prevalence of myopia in many countries in Asia, we elected
to use the most appropriate functional presbyopia preva-
lence figure, thus excluding people with low to moder-
ate myopia from the estimate.
Variations in methods explain some of the preva-
lence differences across the studies reported here. Meth-
odological variations included the type of near visual acu-
ity chart, working distance (predetermined or patient
preference), type of illumination or test conditions (in-
doors or outdoors), and the survey method used. Pupil
miosis increases depth of focus, assisting near vision par-
ticularly in bright sunlight5; this effect partly accounts
for the lower prevalence of functional presbyopia in the
Tanzanian and Timorese studies that were performed out-
doors18,37,38 compared with the Brazilian and Indian stud-
ies that were performed indoors.17,21
More epidemiological research in presbyopia is needed
to decrease the assumptions and generalizations re-
quired for a better global estimate. As more data be-
come available, an increasingly accurate picture of the
burden of presbyopia will emerge.
Future studies of presbyopia should follow standard-
ized definitions, protocols, and measurement methods
similar to those developed by the Refractive Error Study
in Children protocol for the World Health Organiza-
tion’s Prevention of Blindness and Deafness Program.48
We propose using functional presbyopia with a cutoff at
0.4 logMAR (N8 at 40 cm) as it is the most practical di-
rect measure of habitual near vision impairment.
Table 4. Estimate of Global Uncorrected and Undercorrected Presbyopia
Region
Population
Without Adequate
Optical Correction, %
Population Without Adequate Optical Correction
in Specified Year, No. in Millions
2005 2010 2020 2050
More-developed countries within regionsa
Australia and New Zealand 16 1.2 1.3 1.6 2.1
North America 16 9.9 11.3 14.4 19.3
Europe 4 9.9 10.5 11.2 11.3
Japan 16 4.8 5.0 5.5 5.0
Total 25.9 28.2 32.7 37.7
Less-developed countries within regionsa
Melanesia 61 0.5 0.6 0.8 1.7
Micronesia 61 0.0 0.0 0.0 0.1
Polynesia 61 0.0 0.0 0.1 0.1
Caribbean 61 3.7 4.2 5.0 6.2
Central America 61 12.8 15.4 21.6 37.8
South America 61 39.5 45.4 58.3 93.7
Eastern Africa 70 3.4 3.7 4.9 12.9
Middle Africa 70 1.6 1.8 2.2 5.3
Northern Africa 70 18.7 22.1 30.2 58.9
Southern Africa 70 5.3 5.5 5.6 7.7
Western Africa 70 12.4 13.7 17.5 43.7
Eastern Asia, excluding Japan 70 155.0 181.9 205.2 219.2
South-central Asia 70 111.7 128.3 146.6 166.2
Southeastern Asia 70 41.0 47.9 55.1 62.9
Western Asia 70 20.6 24.8 29.6 35.2
Total 426.2 495.4 582.7 751.3
Least-developed countries within regionsa
Melanesia 74 0.1 0.1 0.1 0.2
Caribbean 74 0.7 0.8 1.0 2.2
Eastern Africa 94 21.4 24.0 31.6 84.5
Middle Africa 94 7.5 8.4 11.1 30.6
Northern Africa 94 5.6 6.6 8.9 19.3
Southern Africa 94 0.2 0.2 0.2 0.2
Western Africa 94 8.2 9.4 12.9 37.0
South-central Asia 74 13.7 16.2 19.0 22.2
Southeastern Asia 74 5.7 6.6 7.6 8.7
Western Asia 74 1.5 1.8 2.1 2.5
Total 64.5 74.0 94.5 207.4
Global total 516.6 597.6 709.9 996.4
aThe United Nations Department of Economics and Social Affairs classifies all countries in Europe and North America plus Australia, New Zealand, and Japan as
more developed, and all other countries are either less or least developed.34
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PRESBYOPIC CORRECTION
IN AN EYE CARE SYSTEM
Presbyopic correction can play an important role in the
development of an integrated eye care system. The need
for spectacles for presbyopia is already a major driver
encouraging people to seek eye care,40,49-51 especially in
developing countries.51 Visiting an eye care practitioner
enables the detection of potentially permanently blind-
ing diseases such as cataract, diabetes, and glaucoma at
the same time if the eye care personnel are suitably
trained.50 Having the capacity to provide a solution to
presbyopic problems will encourage even more people
to seek care, and it allows for a more integrated model
of eye care than vertical approaches such as those using
cataract case finders.
However, it is also important to recognize that while
spectacles provide an easy answer to the need for pres-
byopic correction, the mere handing out of spectacles
without an appropriate eye examination biases against
quality eye care for everyone regardless of socioeco-
nomic status, sex, or geographic circumstance. Cou-
pling spectacle distribution to meaningful eye care is an
important link in the blindness prevention chain from
community to hospital.2,37 Random spectacle distribu-
tion breaks the chain of patient care and is counter-
productive.
ECONOMICS
The economics of correcting presbyopia are also impor-
tant to consider. Correction of refractive errors via an eye
examination and provision of spectacles has been dem-
onstrated to be one of the simplest and most cost-
effective blindness prevention interventions.49 While the
monetary value of the burden related to presbyopia is un-
known, presbyopia is particularly suited to correction with
low-cost ready-made spectacles.31,52,53
Primary eye care consistently struggles for sustain-
ability in countries without universal health care (indi-
Table 5. Estimate of Global Disability Caused by Uncorrected Presbyopia
Region
Population Feeling
Disabled by Reduced
Near Vision, %
Population Feeling Disabled by Reduced Near Vision
in Specified Year, No. in Millions
2005 2010 2020 2050
More-developed countries within regionsa
Australia and New Zealand 7 0.5 0.6 0.7 0.9
North America 7 4.3 4.9 6.3 8.4
Europe 7 17.4 18.3 19.7 19.8
Japan 7 2.1 2.2 2.4 2.2
Total 24.4 26.1 29.0 31.4
Less-developed countries within regionsa
Melanesia 58 0.5 0.6 0.8 1.6
Micronesia 58 0.0 0.0 0.0 0.1
Polynesia 58 0.0 0.0 0.0 0.1
Caribbean 58 3.5 4.0 4.7 5.9
Central America 58 12.2 14.6 20.5 36.0
South America 58 37.6 43.2 55.4 89.1
Eastern Africa 53 2.5 2.8 3.7 9.8
Middle Africa 53 1.2 1.3 1.7 4.0
Northern Africa 53 14.2 16.8 22.9 44.6
Southern Africa 53 4.0 4.2 4.3 5.8
Western Africa 53 9.4 10.4 13.2 33.1
Eastern Asia, excluding Japan 53 117.4 137.7 155.4 166.0
South-central Asia 53 84.5 97.1 111.0 125.8
Southeastern Asia 53 31.0 36.3 41.7 47.6
Western Asia 53 15.6 18.8 22.4 26.6
Total 333.7 387.8 457.8 595.8
Least-developed countries within regionsa
Melanesia 70 0.0 0.1 0.1 0.2
Caribbean 70 0.7 0.7 1.0 2.1
Eastern Africa 70 15.9 17.9 23.5 62.9
Middle Africa 70 5.6 6.3 8.3 22.8
Northern Africa 70 4.2 4.9 6.6 14.4
Southern Africa 70 0.1 0.1 0.1 0.2
Western Africa 70 6.1 7.0 9.6 27.5
South-central Asia 70 12.9 15.3 18.0 21.0
Southeastern Asia 70 5.4 6.3 7.2 8.2
Western Asia 70 1.4 1.7 2.0 2.3
Total 52.4 60.2 76.4 161.7
Global total 410.5 474.1 563.2 788.9
aThe United Nations Department of Economics and Social Affairs classifies all countries in Europe and North America plus Australia, New Zealand, and Japan as
more developed, and all other countries are either less or least developed.34
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cating a government’s lack of willingness to pay) or a
wealthy population base (where there is no community-
based ability to pay). If linked in a constructive way with
primary eye care, a global low-cost spectacle delivery sys-
tem can contribute to the economic sustainability of pri-
mary eye care. A link between primary eye care, refrac-
tion, and dispensing will facilitate the development of a
system to finance these services.
CONCLUSIONS
Functional presbyopia, experienced by people who
cannot see clearly at near, affects more than 1 billion
people, 517 million of whom do not have adequate near
vision correction. Significant near vision disability is
experienced by 410 million people. Access to spectacles
for correction of presbyopia is not equal across the
world—67% of people with presbyopia and 94% of
people with significant near vision disability due to un-
corrected presbyopia live in less- or least-developed
countries. When the number of people with significant
near vision impairment due to near uncorrected refrac-
tive error (410 million) is added to those with blindness
or impaired vision due to distance uncorrected refrac-
tive error (153 million),4the number of people who
would benefit from spectacles is an estimated 563 mil-
lion. If the goal of Vision 2020 to eliminate unnecessary
blindness and impaired vision, in this case due to un-
corrected refractive error, is to be achieved, planning
will have to include the provision of human resources,
affordable spectacles, and systems of delivery for these
half-billion people in need.
Submitted for Publication: March 28, 2008; final revi-
sion received July 6, 2008; accepted August 19, 2008.
Correspondence: Brien A. Holden, PhD, DSc, Interna-
tional Centre for Eyecare Education, Level 4, North Wing,
Rupert Myers Bldg, Gate 14, Barker Street, The Univer-
sity of New South Wales, Sydney, NSW 2052, Australia
(b.holden@ier.org.au).
Financial Disclosure: None reported.
Author Contributions: Drs Holden and Ho and Messrs
Fricke and Wong had full access to all of the data in the
study and take responsibility for the integrity of the data
and the accuracy of the data analysis.
Funding/Support: This work was supported by a public
health grant from the Institute for Eye Research.
Additional Contributions: Judith Stern, BOptom, Thomas
Naduvilath, PhD, and Nerida Cole, PhD, helped with the
manuscript.
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Ophthalmological Ephemera
In 1795, Dr Isaac Thompson concocted an eye water of zinc sulfate, saffron, camphor, and rose water. It was sold as late
as 1939. This is 1 of a series of 32 medical trade cards advertising the product from 1875 through 1895.
Courtesy of: Daniel M. Albert, MD, MS
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... The global presbyopic population has been estimated to have grown to one billion, and thus the demand for presbyopic correction has steadily grown over time [1]. Multifocal contact lenses (CLs) have demonstrated significant efficacy in facilitating optimal visual acuity across various distances, ranging from near to far, thereby obviating the need for spectacles among presbyopic subjects. ...
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Background/Objectives: The objective was to assess visual performance and the overall satisfaction of extended-depth-of-focus (EDOF) contact lenses (CLs) in a presbyopic population. Methods: We prospectively investigated visual acuity at all distances (0.3, 0.4, 0.5, 0.7, 1, and 5 m), higher-order aberrations (HOAs), contrast sensitivity function, and overall satisfaction score, before and during EDOF CL wear in 42 eyes of 21 presbyopic subjects (1 man and 20 women). Results: Binocular visual acuity at 0.3, 0.5, 0.7, 1, 2, 3, and 5 m when wearing EDOF CLs was 0.01 ± 0.14, −0.08 ± 0.02, −0.08 ± 0.02, −0.08 ± 0.00, −0.08 ± 0.00, −0.08 ± 0.02, and −0.07 ± 0.02, respectively. We found a significant improvement at near to intermediate distances (0.3, and 0.5 m), but no significant change at intermediate to far distances (0.7, 1, 2, 3, and 5 m) between before and during CL wear. The area under the log contrast sensitivity function was not significantly changed under photopic nor mesopic conditions (p = 0.099, and p = 0.689). Ocular third-order aberrations, fourth-order aberrations, or total HOAs for a 4 mm pupil significantly increased. The overall satisfaction score significantly improved by wearing EDOF CLs. Conclusions: EDOF CLs significantly improved visual acuity at near to intermediate distances, while maintaining far vision, and the effect of contrast sensitivity was minimal, suggesting the viability of presbyopic correction in such candidates.
... It is well established that the accommodative tuning range of focal length declines steadily with age. A significant loss of accommodative ability, known as presbyopia, typically occurs around the age of 45, with accommodation being completely lost by the age of 65 [7,8]. Presbyopia is primarily attributed to age-related stiffening and thickening of crystalline lens tissues [9,10]. ...
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Lens tension is essential for accommodative vision but remains challenging to measure with precision. Here, we present an optical coherence elastography (OCE) technique that quantifies both the tension and elastic modulus of lens tissue and capsule. This method derives mechanical parameters from surface wave dispersion across a critical frequency range of 1-30 kHz. Using isolated lenses from six-month-old pigs, we measured intrinsic anterior capsular tensions of 0-20 kPa and posterior capsular tensions of 40-50 kPa, induced by intra-lenticular pressure at the cortical surface. Young's modulus (E) was 1.9 MPa for anterior capsules and 1.2 MPa for posterior capsules. Tensions in cortical tissue (E ~ 10 kPa) were below 1 kPa. Biaxial zonular stretching (~4% strain) increased anterior capsular tension from near zero to 64 kPa. This acousto-optical method holds significant promise for diagnosing and managing accommodative dysfunctions through lens mechanics assessment in clinical settings.
... Refractive error and presbyopia are two of the most common visual impairments globally, affecting millions of people across all age groups. In Bangladesh, these conditions remain a significant public health concern due to limited access to quality eye care services and widespread poverty [1][2][3]. Refractive errors, such as myopia, hyperopia, and astigmatism, are caused by irregularities in the shape of the eye, leading to blurred vision. Presbyopia, on the other hand, is an age-related condition that impairs near vision, typically affecting individuals over 40 years of age [4][5][6][7]. ...
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Background: Refractive error and presbyopia are among the most common visual impairments globally, with Bangladesh facing high prevalence rates due to limited access to eye care and widespread poverty. While corrective glasses are an effective solution, awareness and access remain significant barriers, particularly in rural areas. Objective: This study aims to assess the prevalence of refractive error, visual impairment, and presbyopia in Bangladesh, and to identify the challenges in meeting the visual needs of the population. Method: A cross-sectional descriptive study was conducted from January 2021 to January 2024, in Southern Medical College & Hospital, Chattagram. A random sample of 1,000 individuals aged 15-49 years was selected. Data collection included structured interviews and clinical eye examinations to assess visual acuity, refractive errors, and presbyopia, with subsequent statistical analysis of prevalence rates and unmet needs. Results: The study found that refractive error and presbyopia increased with age, with 16.5% of participants experiencing refractive error and 62% affected by presbyopia. Spectacle coverage was low (13.3% for refractive error and 3.2% for presbyopia), with significant gender differences in unmet need, particularly among females (90.6%). A lack of awareness was the primary reason for not using optical services, affecting 92.8% of those with refractive error and 95.9% of those with presbyopia. Conclusion: The study highlights the substantial burden of uncorrected refractive error and presbyopia in Bangladesh, with low spectacle coverage and high unmet need. The main barrier to vision correction is a lack of awareness rather than financial constraints. Interventions are needed to increase awareness, improve access to affordable spectacles, and address gender disparities in eye care.
... It is well established that the accommodative tuning range of focal length declines steadily with age. A significant loss of accommodative ability, known as presbyopia, typically occurs around the age of 45, with accommodation being completely lost by the age of 65 [7,8]. Presbyopia is primarily attributed to age-related stiffening and thickening of crystalline lens tissues [9,10]. ...
Preprint
Full-text available
Lens tension is essential for accommodative vision but remains challenging to measure with precision. Here, we present an optical coherence elastography (OCE) technique that quantifies both the tension and elastic modulus of lens tissue and capsule. This method derives mechanical parameters from surface wave dispersion across a critical frequency range of 1-30 kHz. Using isolated lenses from six-month-old pigs, we measured intrinsic anterior capsular tensions of 0-20 kPa and posterior capsular tensions of 40-50 kPa, induced by intra-lenticular pressure at the cortical surface. Young's modulus (E) was 1.9 MPa for anterior capsules and 1.2 MPa for posterior capsules. Tensions in cortical tissue (E ~ 10 kPa) were below 1 kPa. Biaxial zonular stretching (~4% strain) increased anterior capsular tension from near zero to 64 kPa. This acousto-optical method holds significant promise for diagnosing and managing accommodative dysfunctions through lens mechanics assessment in clinical settings.
... In 2018, approximately 1.09 billion people worldwide lived with functional presbyopia, 1 826 million of whom are uncorrected or undercorrected. 2 Low-and middle-income countries (LMICs) bear 90% of this burden, 3 but the correction rate is as low as 10%. 4 5 Substantial evidence [6][7][8][9] has shown that uncorrected presbyopia can reduce work performance at close distances. Furthermore, one recent cohort study of female textile workers in Bangladesh showed that uncorrected presbyopia is associated with earning $6.51 less per month than those with correction and no vision loss. ...
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Objective To understand if presbyopia correction could empower older craftswomen entrepreneurs living in Zanzibar. Design Mixed-method, before-after intervention study. Setting Unguja and Pemba islands, Zanzibar. Participants 209 craftswomen (weaving, tailoring and sewing, pottery and producing oil and making soaps) 40 years and older with correctable presbyopia, with no other ocular morbidities. Intervention Eye health assessment and near vision spectacle correction for 6 months. Primary and secondary outcomes Change in economic, social, psychological and political empowerment (4-point Likert scale responses) before and after correction. Odds ratios were calculated to determine the likelihood of upward movement on the Likert scale. Five focus group interviews were conducted to explore the craftswomen’s daily experiences concerning vision correction and empowerment, and subsequently, narrative analysis was conducted. Results Of the 209 craftswomen who completed the baseline survey from 4 to 21 April 2022, 157 (75.1%) were successfully followed up from 6 to 27 October 2022. Craftswomen reported significantly greater economic, social, psychological and political empowerment in 14 out of 18 statements (77.8%) (p<0.05). Qualitative responses showed that after correction, craftswomen reported having greater autonomy in running the business and improved income, better decision-making power for their business and children, greater independence and confidence and greater participation in problem-solving for the community and appointing leaders. We did not observe a significant change in the following: ability to make decisions for their family, understanding their capabilities, ability to be elected as a leader and ability to advise government leaders. Conclusion The correlation between presbyopia correction and empowerment among older Zanzibari craftswomen is mostly positive. Some aspects of empowerment require further investigation with an extended timeframe.
Article
Background A pilot eyecare programme aimed to address the urgent eye health needs of older Zanzibari craftswomen. We investigated the impact of correcting presbyopia on their subjective well-being (SWB) 6 months post-correction and assessed the cost-effectiveness of a women-targeted presbyopia correction programme. Methods This study involved Zanzibari craftswomen aged 40 and older with presenting and corrected distance visual acuity better than 6/12 in both eyes and were presbyopic. Using a before–after method, we assessed SWB on a 10-point scale before and after providing free spectacles. Mean SWB scores and differences pre-correction and post-correction were calculated. Programme costs were analysed to determine the cost per SWB score gained and the monthly cost for each SWB score improvement. Additionally, scenario analysis estimated costs for 12 approaches. Results Of 282 craftswomen, 209 met the eligibility criteria. SWB scores significantly increased from 3.34 to 8.14 post correction (p<0.001). Screening costs totalled US12885.84,withanaveragecostofUS12 885.84, with an average cost of US45.69 per craftswoman screened and US61.66perpresbyopiaidentification.ThetotalprogrammecostwasUS61.66 per presbyopia identification. The total programme cost was US14,574.69. One hundred fifty-four craftswomen experienced increased SWB, with a total of 747 score gains. Achieving one SWB score improvement cost an average of US19.50,withamonthlyaveragecostofUS19.50, with a monthly average cost of US3.40 per improvement. Utilising woman screeners, organised transport and ready-made spectacles appeared to be the most cost-effective approach. Conclusion Correcting presbyopia through a targeted eyecare programme significantly enhanced SWB among craftswomen. While the programme seems cost-effective, further research is warranted to explore long-term economic benefits and definitively assess cost-effectiveness in larger studies.
Chapter
Cataracts, an inevitable consequence of aging, affect people worldwide [1]. This age-related condition is accompanied by another visual problem, presbyopia, the gradual decline in near vision [2]. Projections estimate that the global prevalence of presbyopia will reach approximately 1.8 billion people by 2050 [3]. While eyeglasses serve as the traditional solution for presbyopia, a growing number of people are seeking a more comprehensive solution.
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SIGNIFICANCE Evaluating the visual challenges and refractive correction solutions of presbyopic orienteers identifies features of relevance to optometric management of the visual needs of active presbyopes. PURPOSE Orienteering is a unique sport requiring visual clarity at a range of viewing distances and has a high proportion of presbyopic participants. This study evaluates the vision corrections used by presbyopic orienteers, specifically aiming to characterize the prevalence of different vision correction options used and to explore the strengths and limitations of different vision correction solutions. METHODS Orienteers 40 years or older completed an online questionnaire consisting of multiple-choice questions covering personal demographics, orienteering participation, and visual corrections worn in everyday life and for orienteering. Free-text questions asked for further information about the corrections used and advice received from eye care practitioners were analyzed using content analysis. RESULTS There were 469 respondents (195 women, 274 men; median age category, 55 to 59 years). For the 187 people without distance refractive correction, the most frequent corrections for orienteering were “off the shelf” reading spectacles (n = 95) or use of a compass magnifier (n = 24), and for the 277 people with distance refractive correction, they were progressive addition spectacles (n = 96) and monovision contact lenses (n = 63). The main visual challenges faced by orienteers were seeing map detail, lens obstruction from fogging and rain, and difficulty orienteering in low light in the daytime. An ideal correction needed to provide visual clarity for both map and terrain. No visual correction type consistently addressed all challenges. Orienteers valued personalized discussion with eye care practitioners to address their needs. CONCLUSIONS Optimal visual corrections for presbyopic orienteers are individual, but higher reading additions to clarify map detail, contact lenses to avoid lens obstruction, additional light, and solutions that provide clear vision at all viewing distances while avoiding the reading add blurring the ground at the orienteer's feet should be considered. Personalized care is necessary to optimize visual correction solutions.
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Because of the pressure for timely, informed decisions in public health and clinical practice and the explosion of information in the scientific literature, research results must be synthesized. Meta-analyses are increasingly used to address this problem, and they often evaluate observational studies. A workshop was held in Atlanta, Ga, in April 1997, to examine the reporting of meta-analyses of observational studies and to make recommendations to aid authors, reviewers, editors, and readers. Twenty-seven participants were selected by a steering committee, based on expertise in clinical practice, trials, statistics, epidemiology, social sciences, and biomedical editing. Deliberations of the workshop were open to other interested scientists. Funding for this activity was provided by the Centers for Disease Control and Prevention. We conducted a systematic review of the published literature on the conduct and reporting of meta-analyses in observational studies using MEDLINE, Educational Research Information Center (ERIC), PsycLIT, and the Current Index to Statistics. We also examined reference lists of the 32 studies retrieved and contacted experts in the field. Participants were assigned to small-group discussions on the subjects of bias, searching and abstracting, heterogeneity, study categorization, and statistical methods. From the material presented at the workshop, the authors developed a checklist summarizing recommendations for reporting meta-analyses of observational studies. The checklist and supporting evidence were circulated to all conference attendees and additional experts. All suggestions for revisions were addressed. The proposed checklist contains specifications for reporting of meta-analyses of observational studies in epidemiology, including background, search strategy, methods, results, discussion, and conclusion. Use of the checklist should improve the usefulness of meta-analyses for authors, reviewers, editors, readers, and decision makers. An evaluation plan is suggested and research areas are explored.
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The global initiative, Vision 2020: The Right to Sight, established by the World Health Organization (WHO) and the International Agency for the Prevention of Blindness, has created valuable and effective collaborations of organisations involved in a wide range of eyecare and community healthcare activities aimed at the elimination of avoidable blindness and impaired vision.
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Este artigo teve como objetivo estimar a prevalência de presbiopia em adultos com trinta anos ou mais e explorar características associadas, como variáveis demográficas, sócio-econômicas e individuais. Realizou-se um estudo transversal de base populacional com 3.007 adultos acima de trinta anos em Pelotas, Rio Grande do Sul, Brasil. Avaliou-se a acuidade visual para perto com a tabela de Jaeger e as outras variáveis foram investigadas através de questionários padronizados e pré-codificados. Encontrou-se uma prevalência de 54,7% de presbiopia na amostra estudada. Quando a acuidade visual foi medida utilizando meios de correção visual, a prevalência encontrada foi de 29,3%. As variáveis idade e sexo feminino se mostraram associadas com o desfecho, controlando-se para fatores de confusão. Cerca de 42,4% da amostra referiram não necessitar da visão de perto nas suas tarefas habituais. Concluiu-se que a presbiopia tem elevada prevalência na população adulta e se relaciona diretamente com o aumento da idade (especialmente após os 45 anos) manifestando-se mais precocemente nas mulheres. Em 30% dos usuários de correção visual a mesma não é adequada para visão de perto.
Article
AIMS To assess the feasibility of providing a stock of ready made spectacles for correction of refractive error in the general population. METHODS Data were collected in the Visual Impairment Project, a population based survey of Victorian residents aged 40 years or older in randomly selected urban and rural sample areas. This included a refractive eye examination and the proportion of subjects with hypermetropia, emmetropia (defined as −1.0 to +1.0D spherical equivalent), and myopia documented in the 40–60 year age group. RESULTS 2595 (54.8%) participants were aged between 40 and 60 years. Those with a best corrected visual acuity of less than 6/12, astigmatism of more than 1.25D, and anisometropia of more than 0.5D were excluded. 516 participants had refractive error which was deemed suitable for correction by “off the shelf” spectacles. This represents 19.9% of all participants between 40 and 60 years of age. Provision of spectacles in 0.5D increments would provide suitable stock spectacles for 85.5% of a −3.0 to +3.0D range or 89.2% of a −3.50 to +3.50D range. CONCLUSIONS Ready made “off the shelf” spectacles could significantly alleviate visual morbidity due to refractive error in up to 20% of an urban population in Australia. This approach may also be useful in developing countries with poor access to optometric services.
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The 2004 tsunami focused unprecedented international aid and resources on Sri Lanka. Among other responses, a program delivered by volunteer optometrists enabled many local people to access eye examinations and spectacles for the first time. The data collected from the eye-care delivery program during 2005 are summarised in this report, as an evidence base for planning future eye-care interventions in these provinces or similar areas. A total of 96 eye clinics were conducted by visiting volunteer optometrists in the northern and eastern provinces of Sri Lanka, at which 20,090 people were examined. Clinical records were reviewed for conditions causing visual impairment, conditions that could cause impaired vision in future if left untreated, eye-care outcomes and barriers to seeking care. Complete records were available for 14,669 people. Seventy-nine per cent of this clinical population had never had an eye examination. Uncorrected refractive error including presbyopia caused visual impairment for 78 per cent (11,388) of people who presented for an eye examination. Cataract caused impaired vision for 15 per cent (2,180) of people and was the main reason for referral beyond primary eye-care, although only five per cent (695) of people presenting were referred for cataract surgery, as local capacity constraints set a visual acuity requirement of 6/36 or worse. The gender and age profiles of people attending the clinics were not consistent with equitable blindness prevention. The high proportion of people who had not previously had an eye examination, particularly those with significant uncorrected refractive error, provides evidence for the acute need for further development and support of community-level eye-care services in the regions visited. Women and older people should be targeted by future programs to achieve equity of blindness prevention.
Article
Samples from the files of two optometrists, one from Ghana and one from Fiji, show that the bifocal additions from two ethnic groups residing in each of these areas differ by about a half diopter throughout the presbyopia transition period of life. These differences seem to be attributable to other factors than differences in age of onset of presbyopia.