Global cost of correcting vision impairment from uncorrected refractive error

Abstract

Objective:
To estimate the global cost of establishing and operating the educational and refractive care facilities required to provide care to all individuals who currently have vision impairment resulting from uncorrected refractive error (URE).

Methods:
The global cost of correcting URE was estimated using data on the population, the prevalence of URE and the number of existing refractive care practitioners in individual countries, the cost of establishing and operating educational programmes for practitioners and the cost of establishing and operating refractive care facilities. The assumptions made ensured that costs were not underestimated and an upper limit to the costs was derived using the most expensive extreme for each assumption.

Findings:
There were an estimated 158 million cases of distance vision impairment and 544 million cases of near vision impairment caused by URE worldwide in 2007. Approximately 47 000 additional full-time functional clinical refractionists and 18 000 ophthalmic dispensers would be required to provide refractive care services for these individuals. The global cost of educating the additional personnel and of establishing, maintaining and operating the refractive care facilities needed was estimated to be around 20 000 million United States dollars (US$) and the upper-limit cost was US$ 28 000 million. The estimated loss in global gross domestic product due to distance vision impairment caused by URE was US$ 202 000 million annually.

Conclusion:
The cost of establishing and operating the educational and refractive care facilities required to deal with vision impairment resulting from URE was a small proportion of the global loss in productivity associated with that vision impairment.

Full text

Bull World Health Organ 2012;90:728–738 | doi:10.2471/BLT.12.104034
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728
Global cost of correcting vision impairment from uncorrected
refractive error
TR Fricke,a BA Holden,b DA Wilson,a G Schlenther,a KS Naidoo,a S Resnikoffa & KD Frickc
Introduction
Uncorrected refractive error (URE) is the most common
cause of vision impairment worldwide and the second most
common cause of blindness.1,2 The aim of this paper was to
estimate the global cost of establishing and operating health-
delivery systems that are capable of providing refractive care
to all individuals who currently have vision impairment
resulting from URE. The estimated cost can be compared
to a previously published estimate of the annual cost of the
productivity lost due to refractive vision impairment world-
wide, of 269 000 million international dollars, equivalent to
202 United States dollars (US$).3 The comparison provides
an indication of the economic return that society might
expect from the investment required to make refractive
care accessible to all. We present an idealized account of the
actions needed to solve the problem of URE globally, which
can serve as a guide and provide an incentive for action. In
reality, uncontrollable socioeconomic, cultural and political
factors complicate the process and make the cost of eliminat-
ing URE unpredictable.
Methods
For this analysis, we used the current World Health Orga-
nization (WHO) denition of distance vision impairment: a
visual acuity worse than 6/18 in the better eye.4 For near vision
impairment, since WHO has not specied a standard, we used
the denition suggested by the International Agency for the
Prevention of Blindness: “vision at the individual’s required
working distance worse than N8 in the better eye”.5
As it has been reported that URE cannot be dealt with by
existing eye care workers,5 we have estimated the extra sta
needed. In doing so, we adhered as closely as possible to each
country’s expectations of the specic personnel required to
provide the various elements of refractive care.
Given the large number of individuals with URE, it was
logical to assume that refractive care should be delivered in
primary-care settings.6 Moreover, WHO noted that, when
refractive care is provided in primary care, the opportunity
should also be taken to identify those who need treatment
for eye disease.7 Consequently, we based our costing of the
infrastructure needed on a vision centre model that provides
both refractive care and screening for ocular disease at the
primary-care level.8,9
We combined data from several sources. Population data
were mostly based on estimates for the middle of 2007 obtained
from the International Data Base, a computerized database
established by the United States Census Bureau that contains
statistical tables of demographic data for 228 countries and
areas of the world.10,11 In doing this, we used the same popu-
lation data as Smith et al.,3 which enabled us to compare our
ndings with estimates of the cost of the productivity lost due
to vision impairment made by those authors. Economic data
included price level indices from the International Compari-
son Program of the World Bank12 and the Asian Development
Bank13 and data on wage levels and resource use in health
care were taken from WHO CHOICE databases.14 Data on
the prevalence of distance and near vision impairment due to
URE in each country were obtained from the publications of
Resniko et al.1 and Holden et al.,2 respectively. e number
of cases of vision impairment in each country was derived
Objective To estimate the global cost of establishing and operating the educational and refractive care facilities required to provide care
to all individuals who currently have vision impairment resulting from uncorrected refractive error (URE).
Methods The global cost of correcting URE was estimated using data on the population, the prevalence of URE and the number of existing
refractive care practitioners in individual countries, the cost of establishing and operating educational programmes for practitioners and
the cost of establishing and operating refractive care facilities. The assumptions made ensured that costs were not underestimated and an
upper limit to the costs was derived using the most expensive extreme for each assumption.
Findings There were an estimated 158 million cases of distance vision impairment and 544 million cases of near vision impairment caused
by URE worldwide in 2007. Approximately 47 000 additional full-time functional clinical refractionists and 18 000 ophthalmic dispensers
would be required to provide refractive care services for these individuals. The global cost of educating the additional personnel and of
establishing, maintaining and operating the refractive care facilities needed was estimated to be around 20 000 million United States
dollars (US$) and the upper-limit cost was US$ 28 000 million. The estimated loss in global gross domestic product due to distance vision
impairment caused by URE was US$ 202 000 million annually.
Conclusion The cost of establishing and operating the educational and refractive care facilities required to deal with vision impairment
resulting from URE was a small proportion of the global loss in productivity associated with that vision impairment.
a Brien Holden Vision Institute, Sydney, Australia.
b Brien Holden Vision Institute, University of New South Wales, Ruper Myers Building, Gate 14 Barker Street, Sydney, NSW 2052, Australia.
c Johns Hopkins Bloomberg School of Public Health, Baltimore, United States of America.
Correspondence to BA Holden (e-mail: b.holden@brienholdenvision.org).
(Submitted: 20 February 2012 – Revised version received: 3 June 2012 – Accepted: 4 June 2012 – Published online: 12 July 2012 )

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by combining prevalence data with
population data. To simplify reporting,
we give estimates for the 14 subregions
of the world used in the WHO publica-
tion Global burden of disease 2002: data
sources, methods and results.15
New practitioners required
e number of new practitioners needed
to provide clinical refraction services
was estimated for each country by
calculating how many refractive care
practitioners were required to reach
the ratio of 1:50 000 for the number of
“functional clinical refractionists” to the
population specied by WHO and the
International Agency for the Preven-
tion of Blindness7 and by taking into
account existing human resources. We
dened a functional clinical refractionist
as a person who spends 100% of his or
her clinical time providing refraction
services and estimated the equivalent
number of full-time functional clinical
refractionists available at present from
the percentage of clinical time each
particular type of professional spends
on providing refraction services. For
example, in Australia, although optom-
etrists provide the majority of refraction
services, they have other responsibilities
and we estimated that the equivalent
number of full-time functional clini-
cal refractionists in the country was
half the number of optometrists. Data
sources for the number of practitioners
who were providing refraction services
worldwide are listed in Table 1.
ere are individuals with vision
impairment due to URE in many coun-
tries that do not require additional
refractive care personnel because they
exceed the functional clinical refrac-
tionists to population ratio specied
by WHO and the International Agency
for the Prevention of Blindness.7 For
example, an estimated 1.2 million people
in Australia have distance or near vision
impairment due to URE. Since the coun-
try has 2712 registered optometrists
(equivalent to 1356 full-time refraction-
ists), the functional clinical refraction-
ists to population ratio is 1 to 15 069.16,17
In countries like Australia, we assumed
that the human resources required to
provide clinical refraction services al-
ready existed and, consequently, that the
cost of educating additional refractive
care personnel would be zero.18 In these
cases, untreated vision impairment was
regarded as resulting from diculties
accessing services.
We were unable to find any pub-
lished data on the number of ophthal-
mic dispensing personnel required
for the prevention of blindness. As
dispensing personnel usually work in
conjunction with refractive care per-
sonnel, our estimate for the number of
dispensing personnel required in each
region was a proportion of the number
of functional clinical refractionists re-
quired. We varied the proportion with
the average prevalence of refractive
error in each region because, in areas
where the prevalence is low, clinical
staff will probably have to examine
more people with normal vision or
eye disease that require referral for
each case of refractive error found. In
contrast, dispensing personnel will be
involved only when a refractive error is
detected. Consequently, the ratio of dis-
pensing personnel to functional clinical
refractionists was taken to be 1:5 in Af-
rica, 1:2 in Asia, 1:4 in Oceania and 1:3
in Europe, the eastern Mediterranean
and the Americas. Given that these
ratios were chosen arbitrarily, we used
a ratio of 1:1 in every country when
establishing an upper limit for costs.
Cost of educating practitioners
In estimating the cost of educating the
new practitioners required to provide
refractive care in each country, we made
several assumptions about capital and
running costs.
For economic reasons, we grouped
together countries that were similar
geographically and politically and as-
sumed that a shared institution could
provide education for a region requiring
1500 functional clinical refractionists.
For example, we estimated the capital
costs of the two educational facilities
required in Anglophone eastern Africa
for educating 2981 functional clinical re-
fractionists in Ethiopia, Kenya, Uganda
and the United Republic of Tanzania
combined. When such combinations
were not possible, we attempted to nd
a compromise. For example, we postu-
lated that an institution in Mozambique
could serve all of Lusophone Africa. In
this case, the cultural and linguistic ties
between populations were considered
to outweigh the fact that the combined
total of functional clinical refractionists
required was only 585. e data sources
for the capital and running costs of edu-
cational facilities for new refractive care
practitioners are given in Table 2. When
no data were available for a country, we
extrapolated costs in similar countries
by adjusting the price level index for
dierences in the cost of living between
countries. Price level indices obtained
from e World Bank provide a broad
measure of costs rather than costs spe-
cic to education.12 e cost of educating
dispensing personnel was also included
in educational costs, as was an additional
sum to cover continuing professional
development for all personnel for a
period of 5 years.
Cost of new refractive care
facilities
We estimated the cost of establishing,
equipping and running refractive care
facilities for the new practitioners re-
quired in each country. First, the num-
ber of new care facilities was estimated.
When the functional clinical refraction-
ists–to-population ratio was less than
1 to 50 000, we calculated the number
of new practitioners required using
the method described above. When
the ratio was higher than 1 to 50 000,
we used a problem-solving approach
to estimate the cost of increasing the
accessibility of the existing workforce.
With the problem-solving approach,
we estimated the number of new or
redeployed personnel required from
the total number of URE cases needing
treatment by assuming that a full-time
functional clinical refractionist can deal
with 2067 cases of vision impairment
due to URE per year on average and that
each individual has to be reassessed and
provided with replacement spectacles
every 5 years on average. e average of
2067 cases per year was derived by as-
suming that a practitioner works 5 days
a week, has 6.2 weeks annual leave and
sees six patients with vision impairment
due to URE per day. Since half of these
patients will have both distance and
near vision impairment, in eect a total
of nine cases of vision impairment due
to URE will be dealt with per working
day. Regardless of which method was
used to estimate the number of new or
redeployed practitioners needed, we
calculated the number of care facilities
required by dividing by 1.3, based on an
estimation of approximately four prac-
titioners for every three vision centres.
Second, the capital cost of estab-
lishing and equipping the new facilities
required was estimated. In most cases,
we used an average of US$ 50 000 per
care facility, which was based on infor-
mation provided by the international

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Table 1. Data sources on existing refractive care practitioners, worldwide, 2006–2010
Country Data source
Angola, Benin, Botswana, Cape Verde, Central African Republic, Chad,
Comoros, Congo, Democratic Republic of the Congo, Equatorial Guinea,
Eritrea, Ethiopia, Madagascar, Malawi, Mauritius, Mozambique, Namibia,
Niger, Senegal, South Africa, Togo, Uganda, Zimbabwe
Human resources for eye care – Africa Region, International Agency
for the Prevention of Blindness Africa Human Resource Day, 19
September 2006
Kenya, Sudan, United Republic of Tanzania, Zambia Regional analysis of southern and eastern Africa, International Centre
for Eyecare Education, 2008
Cameroon, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Nigeria, Sierra
Leone
West Africa refractive error workshop, Sightsavers International,
January 2008
Algeria, Bahrain, Islamic Republic of Iran, Jordan, Pakistan, Saudi Arabia,
Sudan
Hasan Minto, World Conference of Optometric Education, Durban,
22–24 September 2010
Bhutan, Indonesia, Maldives, Myanmar, Sri Lanka, Thailand Mid-level ophthalmic personnel in South-East Asia, WHO Regional
Office for South-East Asia, May 2002
Australia Horton, Kiely and Chakman, Clin Exp Optom 2006; Kiely, Horton and
Chakman, Clin Exp Optom 2010; Kiely and Chakman, Clin Exp Optom
2011
Cook Islands, Fiji, Samoa, Tonga Ramke et al., Clin Exp Ophth 2007
Nepal Prakash Paudel, personal communication, 10 February 2009
Indonesia Cheni Lee, personal communication 2009
India Delhi Declaration (2010) and Prakash Paudel and GN Rao, personal
communication (2009)
Singapore http://en.wikipedia.org/wiki/Optometry_in_Singapore (accessed 5
August 2009)
Cambodia, Vanuatu, Viet Nam Suit May Ho, personal communications, 28 July 2009 and 6
November 2009
Afghanistan, Bangladesh Fred Hollows Foundation situational analyses (2009)
China – Hong Kong Special Administrative Region, China – Taiwan, Japan,
Malaysia, Philippines, Republic of Korea
Essilor Asia-Pacific ophthalmic survey (11 October 2004)
New Zealand New Zealand Optometrists Association (http://www.nzao.co.nz/
eye_health.html, accessed 5 August 2009)
China Daniel Cui, personal communication (2009)
Malaysia http://www.amoptom.org/ and http://www.fskb.ukm.my/, both
accessed 6 November 2009
Mongolia, Papua New Guinea, Solomon Islands International Centre for Eyecare Education situational analyses
(2009)
Nauru, Papua New Guinea Jambi Garap, personal communication, 6 November 2009
Timor-Leste International Centre for Eyecare Education training reports for Timor-
Leste (2005)
Afghanistan MSc theses summaries, Community Eye Health, 2007; 20(61):7–15
Serbia, Montenegro Serbian Association of Opticians and Optometrists (http://www.
uoosrbije.org/, accessed 6 November 2009)
Costa Rica Ruggeiro and Gloyd, Optom Vis Sci, 1995
United States of America United States Department of Labour (http://www.bls.gov/oco/
ocos073.htm, accessed 10 February 2009)
Canada University of Waterloo, Canada (http://www.optometry.uwaterloo.
ca/prospective/od/career.html, accessed 10 February 2009)
Brazil, Chile, Colombia, Cuba, Dominican Republic, Ecuador, El Salvador,
Guatemala, Honduras, Mexico, Nicaragua, Panama, Paraguay, Uruguay,
Venezuela
International Agency for the Prevention of Blindness Latin America
Regional Office (http://www.v2020la.org/orbisread/Indicators05.
htm) plus Van Lansingh, personal communication (2010)
Argentina, Peru Guillermo Carrillo (International Association of Contact Lens
Educators Latin America coordinator) via Percy Lazon, personal
communication (27 July 2009)
Antigua and Barbuda, Bahamas, Barbados, Belize, Dominica, Grenada Nigel St Rose presentation, World Conference of Optometric
Education meeting, Durban, 22–24 September 2010
Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Finland,
France, Germany, Greece, Hungary, Ireland, Italy, Netherlands, Norway,
Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey,
United Kingdom
European Council of Optometry and Optics blue book 2008 (http://
www.ecoo.info/) plus Cathleen Fedke and Fabian Conrad, personal
communications (2009)
Islamic Republic of Iran Aidin Safvati, personal communication, 6 July 2009
(continues. . .)

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charity Sightsavers and published by the
International Agency for the Prevention
of Blindness.5 e amount includes the
cost of equipping care facilities with
bulk-purchased equipment, such as
clinical refractive equipment, ocular
health screening equipment, ophthalmic
dispensing equipment and accounting
and business equipment, and the cost
of start-up stock.
Third, we estimated the cost of
running the new facilities required for
a period of 5 years, on the assumption
that costs would be recovered from
charges to patients during this period.
Running costs included salaries, rent
and electricity, water, telephone and
consumable costs. The cost of most
of these items was derived from the
WHO CHOICE database for each
geographical subregion.14 The cost of
consumables was calculated on the
assumption that 72.4% of individuals
used ready-made spectacles and 27.6%
used custom-made spectacles,19 with
the cost of each type being based on the
real costs reported by the International
Centre for Eyecare Education.20 In addi-
tion, it was assumed that each refractive
care unit paid salaries to 1.3 refrac-
tive care practitioners, 1 receptionist,
0.2 managers and several ophthalmic
dispensing personnel determined for
each region separately, and that every
20 refractive care units required a sup-
port team consisting of 1 programme
director, 2 administrative officers, 1
clerk, 1 messenger, 1 finance director, 1
accountant, 1 public health specialist, 1
health educator, 1 social worker, 1 sup-
plies manager, 4 cleaners and 4 security
officers. Rent was calculated assuming
that each refractive care unit had 1
consulting room 3.5 m × 3 m in size and
1 general purpose room 3.5 m × 4 m in
size, that each fifth refractive care unit
had 1 optical workshop 3.5 m × 3 m in
size and that each twentieth refractive
care unit required a room 6 m × 6 m in
size for the support team.
We estimated an upper limit to
the cost of establishing, equipping and
running refractive care facilities by al-
Country Data source
Kuwait, Qatar, Saudi Arabia, United Arab Emirates Ahmed Alharbi, personal communication, 18 November 2009
United Arab Emirates AMEinfo online business information (http://www.ameinfo.com/,
accessed 6 July 2009)
Syrian Arab Republic Syrian Ophthalmological Society (http://www.sos-sy.com/index.
php?id=37, accessed 6 July 2009) and Nina Tahhan, personal
communication (2009)
Israel Israeli Council of Optometrists (http://www.ico.org.il/, accessed 6
July 2009)
Russian Federation Vadim Davydov (editor, Actual Optometry Journal), personal
communication, 11 November 2009
Estonia Vootele Tame (from Head of Optometry, Tallinn Health College),
personal communication, 11 November 2009
Pakistan Minto H, Awan H, Khan AA, Khan AQ, Yasmin S, Khan N. Situation
analysis of refractive services in Pakistan, Academy for Ophthalmic
Education (2007)
Table 2. Data sources for capital and running costs associated with educating refractive
care practitioners, worldwide, 2006–2010
Country Data source
Australia Queensland University of Technology (vision science and optometry tuition
fees), plus Australian Optometry (October 2009) http://www.optometrists.
asn.au/Publications/AustralianOptometry/tabid/126/language/en-AU/
Default.aspx (accessed 11 July 2012).
Cambodia International Centre for Eyecare Education Cambodia project budgets (2010)
Canada University of Waterloo (optometry tuition fees, 2009)
China, Hong
Kong Special
Administrative
Region
Hong Kong Special Administrative Region Polytechnic University (optometry
tuition fees, 2009)
Fiji Pacific Eye Institute (course fees) and John Szeto, personal communication
(2009)
Indonesia Cheni Lee, personal communication (2009)
Malawi Malawi School of Optometry, University of KwaZulu Natal (optometry tuition
fees, 2010)
Malaysia National University of Malaysia (2009)
Mozambique Irish Aid grant for Mozambique School of Optometry (2010)
Nepal Prakash Paudel, personal communication (10 February 2009)
Nigeria University of Benin (optometry tuition fees, 2010)
Papua New
Guinea
Divine Word University (postgraduate diploma in eye care for nurses course
fees, 2010)
Peru Guillermo Carrillo (International Association of Contact Lens Educators Latin
America coordinator), personal communication, 27 July 2009
Singapore Singapore Polytechnic (optometry tuition fees, 2009)
Sri Lanka International Centre for Eyecare Education Sri Lanka project budgets (2008)
United
Republic of
Tanzania
Tumaini University (health science tuition fees, 2010)
United States
of America
United States Association of Schools and Colleges of Optometry (http://
www.opted.org/, accessed 10 February 2009)
Viet Nam International Centre for Eyecare Education Viet Nam project budgets (2010)
(. . .continued)

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tering critical assumptions so that they
reflected the most expensive scenarios.
First, we assumed that one ophthal-
mic dispenser was employed for each
clinical refractionist. Second, the
ratio of ready-made to custom-made
spectacles was assumed to be 20 to 80,
which is in line with expectations in
the developed world, rather than the
ratio used for the main cost estimate,
which assumed the lowest acceptable
quality of care.21
Results
e estimated number of cases of dis-
tance and near vision impairment due
to URE in WHO regions and subregions
are listed in Tab l e 3. In addition, the
table gives details of the existing number
of functional clinical refractionists and
of the number of new functional clinical
refractionists required to deal with all
cases of vision impairment due to URE.
e estimated number of people in the
world with distance vision impairment
due to URE in the middle of 2007 was
around 158 million and the estimated
number with near vision impairment
resulting from URE was around 544
million. As some individuals will have
both forms of vision impairment, we
estimated the total number of cases of
vision impairment due to URE in the
world, which was around 703 million
in 2007, rather than the number of
individuals.
Table 3. Distance and near vision impairment due to uncorrected refractive error (URE) and number of functional clinical refractionists,a
worldwide, 2006–2010
WHO region and
subregionb
Population
(millions)
Estimated no. of
people aged over
5 years with distance
vision impairment
due to URE
(thousands)
Estimated no. of
people aged over
5 years with near
vision impairment
due to URE
(thousands)
Estimated total
no. of cases of
vision impairment
due to UREc
(thousands)
No. of existing
functional clinical
refractionists
No. of additional
functional clinical
refractionists
required
African Region
D 346 2 976 29 272 32 248 2 605 4 348
E 408 3 326 34 892 38 218 2 380 5 790
Total 754 6 301 64 165 70 466 4 985 10 138
Region of the
Americas
A 346 6 278 18 681 24 959 18 901 0
B 474 6 504 51 241 57 745 5 565 4 906
D 79 1 018 6 732 7 750 442 1 131
Total 898 13 800 76 654 90 454 24 908 6 038
Eastern
Mediterranean
Region
B 151 1 631 12 615 14 246 4 949 516
D 409 4 220 32 607 36 827 4 164 4 024
Total 561 5 852 45 222 51 074 9 113 4 540
European Region
A 423 8 338 6 106 14 444 43 307 16
B 216 3 049 17 222 20 271 4 653 776
C 230 3 702 4 510 8 211 3 610 1 314
Total 868 15 088 27 838 42 926 51 570 2 106
South-East Asia
Region
B 321 4 863 30 411 35 274 2 246 4 168
D1 383 49 684 111 219 160 903 10 169 17 483
Total 1 703 54 547 141 630 196 178 12 415 21 651
Western Pacific
Region
A 157 1 415 6 756 8 171 19 849 0
B1 604 60 482 176 553 237 035 37 707 1 560
Total 1 761 61 897 183 309 245 206 57 556 1 560
Unassigned 57 607 5 636 6 243 6 515 171
Global total 6 602 158 092 544 454 702 546 167 013 46 204
WHO, World Health Organization.
a A functional clinical refractionist is a person who spends 100% of his or her clinical time providing refraction services.
b World Health Organization subregion categories: A: very low child mortality and very low adult mortality; B: low child mor tality and low adult mortality; C: low child
mortality and high adult mortality ; D: high child mortality and high adult mortality; and E: high child mortality and very high adult mor tality.
c The number of cases is reported, as some individuals had both distance and near vision impairment due to URE.

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Fig. 1. Functional clinical refractionists to population ratio, worldwide, 2006–2010
Functional clinical refractionist-to-population ratio < 1:50 000
Functional clinical refractionist-to-population ratio ≥ 1:50 000 and < 1:100 000
Functional clinical refractionist-to-population ratio ≥ 1:100 000 and < 1:200 000
Functional clinical refractionist-to-population ratio > 1:50 000

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Globally, the equivalent of around
167 000 full-time functional clinical
refractionists were dealing with vision
impairment due to URE in 2007. Fig. 1
shows the functional clinical refrac-
tionists to population ratio worldwide.
We estimated that approximately
47 000 additional full-time functional
clinical refractionists and 18 000 addi-
tional ophthalmic dispensers would be
needed to deal with all cases of vision
impairment due to URE. Other mea-
sures would have to be taken in some
countries with an adequate number of
personnel to overcome problems with
access to care.
Tabl e 4 summarizes the estimated
investment required to educate new
refractive care practitioners, includ-
ing ophthalmic dispensing personnel,
in WHO regions and subregions, to
provide continuing professional de-
velopment for 5 years, to establish the
service delivery centres needed and
to fund these centres for 5 years. e
running costs of the centres included
the cost of providing refractive care to
the estimated backlog of 703 million
cases of vision impairment due to URE.
Globally, the total capital investment
for establishing educational institutions
with sucient training capacity was
estimated to be US$ 104 million. An
Table 4. Cost of education and new facilities for additional refractive care practitionersa required to correct vision impairment due to
uncorrected refractive error, worldwide, 2006–2010
WHO region and
subregionb
Capital costs
of education
(thousand US$)
Annual running
costs of education
(US$ per student)
Annual cost of continu-
ing professional
development for 5 years
(thousand US$)
Capital costs of
new refractive
care facilities
(thousand US$)
Annual running costs
of new refractive care
facilities for 5 years
(thousand US$)
Total cost of education
and new refractive care
facilities over 5 yearsc
(thousand US$)
African Region
D10 121 2 922 14 649 183 031 139 511 1 029 207
E11 900 2 774 3 581 230 188 150 258 1 034 003
Total 22 020 2 803 18 230 413 220 289 769 2 063 210
Region of the
Americas
A 0 10 228 6 772 92 864 425 367 2 226 470
B9 285 1 783 4 886 231 910 268 548 1 685 555
D3 317 1 286 284 49 820 34 364 231 687
Total 12 601 2 458 11 942 374 595 728 279 4 143 712
Eastern
Mediterranean
Region
B1 120 2 000 470 55 472 108 996 606 112
D6 929 1 926 916 182 881 73 537 581 844
Total 8 048 1 970 1 386 238 353 182 533 1 187 956
European
Region
A 3 19 832 4 772 53 731 349 476 1 807 157
B1 054 3 970 3 261 76 943 91 262 545 314
C1 443 3 682 778 51 843 41 215 278 871
Total 2 500 12 340 8 811 182 517 481 952 2 631 342
South-East Asia
Region
B12 086 10 495 668 160 299 109 669 750 062
D41 619 1 464 514 295 077 471 273 2 706 111
Total 53 706 4 173 1 182 455 376 580 942 3 456 173
Western Pacific
Region
A 0 17 408 1 140 30 403 132 085 691 968
B4 753 3 495 3 252 900 587 948 088 5 657 323
Total 4 753 6 072 4 392 930 990 1 080 173 6 349 291
Unassigned 27 6 901 461 25 289 36 168 213 194
Global total 103 656 5 947 46 404 2 620 339 3 379 816 20 044 878
US$, United States dollar; WHO, World Health Organization.
a Refractive care practitioners include functional clinical refractionists, who spend 100% of their clinical time providing refraction services, and ophthalmic dispensers.
b World Health Organization subregion categories: A: very low child mortality and very low adult mortality; B: low child mor tality and low adult mortality; C: low child
mortality and high adult mortality ; D: high child mortality and high adult mortality; and E: high child mortality and very high adult mor tality.
c The total cost was the sum of the cost of educating the new refractive care and ophthalmic dispensing personnel (i.e. the capital costs of education, the cost of
educating students and the cost of continuing professional development for 5 years) and of providing new refractive care facilities (i.e. capital costs and 5 years of
running costs) needed to deal with the backlog and all incident cases of distance and near vision impairment resulting from uncorrected refractive error.

Bull World Health Organ 2012;90:728–738 | doi:10.2471/BLT.12.104034 735
Research
Global cost of correcting refractive error
TR Fricke et al.
additional US$ 46 million would cover
continuing professional development
for new personnel for the rst 5 years
of their careers. e total educational
costs were US$ 543 million, which
includes the capital costs of education,
the cost of educating student refractive
care personnel and student ophthalmic
dispensers and the cost of continuing
professional development for all new
personnel for 5 years.
Tabl e 4 also shows that the esti-
mated capital investment needed to
establish service delivery facilities for
the new and redeployed refractive care
personnel required to deal with vision
impairment resulting from URE world-
wide was US$ 2620 million. In addition,
it was estimated that these facilities
would cost US$ 3380 million per year
to operate for the rst 5 years. Assuming
that the revenue generated by the service
would covers costs aer the rst 5 years,
the total investment in service delivery
required (i.e. capital costs and 5 years
of running costs for new refractive care
facilities) to deal with vision impairment
resulting from URE was estimated to be
US$ 19 501 million.
Consequently, the total estimated
cost for educating the new refractive
care and ophthalmic dispensing person-
nel, plus providing the service delivery
facilities needed to deal with the backlog
and all incident cases of distance and
near vision impairment resulting from
URE was US$ 20 045 million.
Our estimated upper limit for the
cost of education and new facilities for
the additional refractive care practi-
tioners required to correct all vision
impairment due to URE globally was
US$ 28 452 million.
Discussion
Several considerations should be taken
into account when interpreting the data
reported in this paper. First, only the
cost of correcting vision impairment as
dened by WHO was estimated and not
the cost of providing vision care to the
world population at the level expected
in developed countries, where the target
acuity is 6/6 for distance vision and N5
for near vision and where many people
want spectacles to correct refractive
error that does not result in vision
impairment. Although we estimate
that globally over 3 000 million people
have some level of refractive error, our
calculations considered only the 703
million cases of distance or near vision
impairment due to URE.
Second, the WHO protocol for eye
examinations22 states that, when visual
loss is due to several coexisting primary
disorders, the “most readily curable” dis-
order should be regarded as the cause of
visual loss. It is possible, therefore, that
the prevalence of vision impairment due
to URE may have been overestimated.
It is rare for refractive care practi-
tioners to be distributed throughout a
country in a way that ensures equitable
access for all communities and, gener-
ally, the poorer and more rural a com-
munity is, the more limited access to
refractive care will be. Even in Europe,
where there is an adequate number
of practitioners, we estimated that an
additional 2000 functional clinical
refractionists as well as the redeploy-
ment of some existing refractive care
personnel was required to overcome
the geographical, financial and other
barriers that restrict access to refractive
care for some individuals with distance
or near vision impairment due to URE.
Consequently, our estimates included
the cost of redeploying practitioners
in countries where the poor distribu-
tion of service providers contributed
to prevalence of vision impairment
due to URE.
In our analysis, we chose not to
anticipate innovative technologies that
may be able to assess and correct refrac-
tive error at a lower cost because of the
uncertainties involved. Our estimates
of the costs of education and service
delivery are, therefore, based on the use
of current techniques and equipment.
Although we made several assump-
tions in estimating costs, we erred on the
side of obtaining the highest estimates.
In addition, our estimate of the upper
limit of the costs, of US$ 28 000 million,
Fig. 2. Loss of gross domestic product due to uncorrected refractive error (URE)a and
costs for additional refractive care practitioners required to correct vision
impairment,b by WHO region, 2006–2010
African
Region
Region
of the Americas
European
Region
Eastern
Mediter-
ranean
Region
South-
East Asia
Region
Western
Pacific
Region
DEABDBDABCBDAB
WHO region and subregionc
United States dollars (millions)
70 000
60 000
50 000
40 000
30 000
20 000
10 000
Adjusted gross domestic product lost because of distance vision impairment due to uncorrected refractive error
Cost of education and new facilities for additional refractive care practitioners required to correct distance and
near vision impairment due to uncorrected refractive error
WHO, World Health Organization.
a The loss in gross domestic product is that resulting only from distance vision impairment caused by
URE.3
b Refractive care practitioners include functional clinical refractionists, who spend 100% of their clinical
time providing refraction services, and ophthalmic dispensers. The costs given are for the additional
practitioners required to treat both distance and near vision impairment caused by URE.
c World Health Organization subregion categories: A: very low child mortality and very low adult
mortality; B: low child mortality and low adult mortality; C: low child mortality and high adult mortality;
D: high child mortality and high adult mortality; and E: high child mortality and very high adult
mortality.

Bull World Health Organ 2012;90:728–738 | doi:10.2471/BLT.12.104034
736
Research
Global cost of correcting refractive error TR Fricke et al.
was made by using the most extreme
values for critical variables.
Smith et al.3 estimated the value of
the productivity lost because of distance
vision impairment due to URE to lie
between 121 400 million and 427 700
million International dollars (equivalent
to US$ 91 300 million to US$ 327 700
million), depending on whether or not
the gure was adjusted to take account
of the labour force participation rate
and the employment rate and was based
on the assumption that people over 50
years of age do not contribute to the
economy. ese two gures give a range
for the possible increase in global gross
domestic product that would result from
providing refractive care for all. In eect,
it is the return on investment.
Fig. 2 shows a comparison between
the estimated loss in gross domestic
product due to distance vision impair-
ment caused by URE in dierent regions
and the cost of education and new
facilities for the additional refractive
care practitioners required to correct
all vision impairment due to URE.
ere would be a substantial return on
the investment required to deal with
vision impairment resulting from URE
in all regions except the African Region.
Globally, the estimated rate of return on
a total investment of US$ 20 045 million
over 5 years, which is the total estimated
cost of dealing with the backlog and all
incident cases of vision impairment due
to URE, would be 59%, even if it was as-
sumed that all expenses were incurred
in the rst year and none of the benets
occurred until the last year and lasted
only 1 year.
Existing refractive care has not been
able to deal with an estimated 703 mil-
lion cases of vision impairment resulting
from URE, which means that the needs
of around 10% of the world’s popula-
tion have not been met. Although our
estimate of the cost of establishing and
operating the educational and refrac-
tive care facilities required to deal with
vision impairment resulting from URE,
of around US$ 20 000 million globally,
can only be approximate, the return on
investment would be substantial. Even
our upper limit for the cost, which
is US$ 28 000 million over 5 years, is
considerably below the estimated eco-
nomic cost of vision impairment due
to URE, which has been estimated to
be US$ 202 000 million each year.3 e
scale of this return on investment means
that correcting vision impairment due
to URE provides a good opportunity for
global development. ■
Acknowledgements
We thank Ahmed Alhardi, Guillermo
Carrillo, Sonja Cronjé, Daniel Cui, Vad-
im Davydov, Neilsen De Souza, Cath-
leen Fedke, Jambi Garap, Suit May Ho,
Muralikrishnan Kartha, Fabian Konrad,
Van Lansingh, Percy Lazon, Cheni Lee,
Hasan Minto, Bao Nguyen, Prakash
Paudel, Prasidh Ramson, GN Rao, Aidin
Safvati, Nina Tahhan, Vootele Tame and
Ma n dy Truo n g.
Funding: Supported by a public health
grant from the Brien Holden Vision In-
stitute. e Australian College of Optom-
etry provided resources for Tim Fricke.
Competing interests: None declared.


       


.)URE
       
  URE   
URE
      




    158     
     544   

   2007   URE  
   47000 
18000


2820
     

202URE
       
       
   URE    


Bull World Health Organ 2012;90:728–738 | doi:10.2471/BLT.12.104034 737
Research
Global cost of correcting refractive error
TR Fricke et al.
摘要
矫正因未矫正屈光不正所致视力损害的全球成本
目的 估计建立和运行为当前所有因未加矫正的屈光不正
（URE）而导致视力损害的个体提供护理所需的全球教育
和屈光保健设施成本。
方法 使用人口、URE的患病率以及各国现有的屈光保健医
生人数、为医生建立和运行教育方案的成本、建立和运行
屈光保健设施的成本等相关数据，估计矫正URE的全球成
本。所做假设确保成本没有被低估，使用每个假设成本最
高的极端情况推导出成本上限。
结果 在2007 年，估计URE造成全球1.58 亿例远视力损害
和5.44 亿例近视力损害。而为这些人提供屈光护理，需要
约4.7 万名额外的全职临床屈光眼科医生和1.8 万名眼科
药剂师。教育增加人员以及建立、维护和运行所需的屈
光保健设施的全球成本估计为200 亿美元（US$）左右，
成本上限是280 亿美元。每年由于URE造成的远视力损害
而遭受的全球国内生产总值的损失估计为2020 亿美元。
结论 相对于视力损害的相关全球生产力损失，为应对URE
造成视力损害而需建立和运行的教育和屈光保健设施的成
本所占比例很小。
Résumé
Coût global de correction d’une déficience visuelle induite par une erreur de réfraction non corrigée
Objectif Estimation du coût global de mise en place et de
fonctionnement des établissements de traitement de la réfraction et
de formation nécessaires pour fournir des soins à toutes les personnes
souffrant actuellement de troubles de la vision résultant d’une erreur
de réfraction non corrigée.
Méthodes Le coût global de la correction des erreurs de réfraction a
été estimé à l’aide des données sur la population, de la prévalence de la
pathologie et du nombre de professionnels de la réfraction existant dans
les différents pays, des coûts de mise en place et de fonctionnement des
programmes éducatifs pour les praticiens et du coût de création et de
gestion des établissements de soins pour la réfraction. Les hypothèses
retenues veillaient à ce que les coûts ne soient pas sous-estimés et un
seuil de coûts maximum a été calculé en utilisant les cas de figure les
plus chers pour chaque hypothèse.
Résultats On a estimé à environ 158 millions le nombre de cas de
déficience de la vision de loin et à 544 millions le nombre de cas de
déficience de la vision de près due à un trouble de la réfraction dans
le monde entier en 2007. Environ 47 000 nouveaux réfractionnistes
cliniques en exercice à temps plein et 18 000 centres ophtalmiques
seraient nécessaires pour fournir des services de soins de la réfraction à
ces patients. Le coût global de formation du personnel supplémentaire
et de mise en place, d’entretien et d’exploitation des installations de soins
de réfraction nécessaires a été estimé à environ 20 milliards de dollars
américains (US $) et le coût maximum était de 28 milliards US $. La perte
estimée de produit intérieur brut mondial en raison de troubles de la
vision de loin causés par la réfraction était de 202 milliards US $ par an.
Conclusion Le coût de mise en place et de fonctionnement des
établissements de soins de la réfraction et de formation nécessaires
pour faire face aux troubles de la vision résultant de pathologies de la
réfraction représente une faible proportion de la perte globale de la
productivité associée à cette déficience visuelle.
Резюме
Глобальная стоимость исправления нарушений зрения, вызванных нескорректированной аномалией
рефракции
Цель Оценить общую стоимость создания и функционирования
образовательных учреждений и учреждений, занимающихся
коррекцией аномалии рефракции, необходимых для оказания
помощи всем лицам, которые в настоящее время страдают от
нарушений зрения, вызванных нескорректированной аномалией
рефракции (НАР).
Методы Глобальная стоимость исправления НАР оценена
на основе данных о населении, распространенности НАР
и количестве существующих медицинских учреждений,
занимающихся коррекцией рефракции, в отдельных странах,
стоимости создания и функционирования образовательных
программ для специалистов-практиков и стоимости создания
и функционирования медицинских учреждений для коррекции
аномалии рефракции. Сделанные в работе допущения
гарантируют отсутствие недооценки расходов. Был рассчитан
верхний предел расходов на основе самых затратных вариантов
для каждого предположения.
Результаты По оценкам, в 2007 г. по всему миру насчитывалось 158
млн. случаев дальнозоркости и 544 млн. случаев близорукости,
вызванных НАР. Чтобы обеспечить медицинскими услугами
этих лиц необходимо приблизительно 47 000 дополнительных
штатных клинических рефракционистов и 18 000 офтальмологов.
Необходимые глобальные расходы на обучение дополнительного
персонала и создание, поддержание и функционирование
медицинских учреждений, занимающихся коррекцией
рефракции, были оценены на уровне 20 млрд. долл. США,
а верхний предел расходов составил 28 млрд. долл. США.
Предполагаемые потери мирового валового внутреннего
продукта из-за ухудшения дистанционного зрения, вызванного
НАР, находятся на уровне млрд. долл. США в год.
Вывод Стоимость создания и функционирования
образовательных учреждений и учреждений, занимающихся
коррекцией аномалии рефракции, необходимых для борьбы
с нарушениями зрения, вызванных НАР, составляет лишь
небольшую часть глобальных потерь производительности,
связанных с данным нарушением зрения.

738
Research
Bull World Health Organ 2012;90:728–738 | doi:10.2471/BLT.12.104034
Global cost of correcting refractive error TR Fricke et al.
Resumen
El coste global de corregir las discapacidades visuales causadas por errores de refracción no corregidos
Objetivo Estimar el coste global del establecimiento y funcionamiento
de las instalaciones educativas y de atención médica refractiva necesarias
para proporcionar atención médica a todas las personas que padecen en
la actualidad una discapacidad visual causada por un error de refracción
no corregido (ERNC).
Métodos El coste global de corregir los ERNC se calculó utilizando datos
sobre la población, la prevalencia de ERNC y el número de especialistas
en atención médica refractiva existentes en cada uno de los países, el
coste del establecimiento y funcionamiento de programas educativos
para especialistas y el coste del establecimiento y funcionamiento de
las instalaciones de atención médica refractiva. Los supuestos aceptados
garantizaron que no se subestimaran los costes y el límite máximo para
los costes se obtuvo utilizando el extremo más caro para cada supuesto.
Resultados Se calcularon 158 millones de casos de discapacidad en
la visión de lejos y 544 millones de casos de discapacidad en la visión
cercana causados por ERNC en 2007. Se necesitarían aproximadamente
47 000 refraccionistas clínicos funcionales adicionales a tiempo
completo y 18 000 ópticos para proporcionar servicios de atención
médica refractiva a esas personas. El coste global de formar al personal
adicional y de establecer, mantener y administrar las instalaciones de
atención médica refractiva necesarias se estimó en unos 20 000 millones
de dólares estadounidenses (US$) y el coste límite superior se estimó
en 28 000 millones de dólares estadounidenses. La pérdida estimada
en el producto nacional bruto global debido a la discapacidad en la
visión de lejos causada por ERNC fue de 202 000 millones de dólares
estadounidenses anuales.
Conclusión El coste del establecimiento y funcionamiento de las
instalaciones de atención médica refractiva necesarias para tratar la
discapacidad visual resultante de ERNC fue una pequeña proporción de
la pérdida global en productividad asociada con esa discapacidad visual.
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