Changing patterns in global blindness: 1988–2008

16 Pages·2008·1.28 MB·English

Community Eye Health 20
TH
ANNIVERSARY
EDITION
Jour n a l

VOLuME 21 | iSSuE 67 | SEPTEMBER 2008
C hanging patterns in global
blindness: 1988–2008
Allen Foster N have data (see Table 1), it was estimated to
A
Professor, International Centre for Eye ST be 45 million: 8 million blind due to uncor-
NI
Health, London School of Hygiene and A rected refractive error and 37 million blind
H
Tropical Medicine, Keppel Street, FG due to other causes.2, 3 It is thought that at
A
London WC1E 7HT, UK. d. least 60% of blind people are women.
n
ma Little was known in 1988 about the
Clare Gilbert h
Professor, International Centre for Eye arra prevalence of low vision (VA <6/18 to 3/60).
Health; Medical Advisor, Sightsavers M F In 2002, the number of people with low vision
International, UK. M was estimated to be 124 million worldwide,
but this excluded low vision due to refractive
Gordon Johnson
error.2 Owing to a lack of data from surveys,
Honorary Professor, International
it has only very recently become possible to
Centre for Eye Health; Emeritus
estimate that there are 145 million people
Professor of Preventive Ophthalmology,
with low vision due to refractive error.3
Institute of Ophthalmology, University
This fi gure brings the overall number of
College London, UK.
people with low vision to 269 million.
Prevalence of visual In total, the number of people with visual
impairment (which includes both low vision
impairment
and blindness) is therefore estimated to be
Changing demography 314 million worldwide.
When the Community Eye Health Journal
was launched in 1988, the world population Causes of blindness
was approximately 5.1 billion. Over the last
Over the last twenty years, the causes of
20 years, it has increased by approximately
blindness have changed in proportion and
30%, reaching 6.7 billion in 2008. During
Cataract has remained the major actual number. Cataract has remained the
the same period, the world population has
cause of blindness worldwide for the major cause of blindness globally. It is partic-
also become proportionally older, as the
past 20 years ularly important in Asia. The numbers of people
number of people aged 65 years and over
Continues overleaf ➤
has increased by approximately 55%, from
Table 1. Most recent estimates of the number of people with visual impairment
320 million in 1988 to 500 million in 2008.
(blindness and low vision) worldwide2,3,4
Since the prevalence of visual impairment
becomes higher as people age, this combi- Defi nition number of
nation of an increasing population and an people (millions)
ageing population is expected to cause a
Blindness (eye disease) <3/60 to no light perception 37
signifi cant increase in the total number of
Blindness (refractive error) <3/60 to light perception 8
blind people.1
Blindness (all causes) 45
Estimates of the number of people
Low vision (eye disease) <6/18 to 3/60 124
with visual impairment worldwide
In 1988, the number of people who were blind Low vision (refractive error) <6/18 to 3/60 145
(visual acuity (VA) <3/60 in the better eye)
Low vision (all causes) 269
was estimated to be 37 million worldwide.
Total: Visual impairment (all causes) 314
By 2002–04, the latest period for which we
IN THIS ISSUE 43 Onchocerciasis and trachoma control: 50 New developments in
what has changed in the past two decades? age-related macular
37 Changing patterns in global blindness: Daniel Etya’ale degeneration
1988–2008 46 Twenty years of childhood blindness: what Lyndon da Cruz
Allen Foster, Clare Gilbert, and Gordon Johnson have we learnt?
Clare Gilbert and Mohammed Muhit 51 The Community Eye Health
40 Cataract surgery at Aravind Eye Hospitals: 48 Eye health in the future: what are the Journal: twenty years on
1988–2008 challenges for the next twenty years?
G Natchiar, RD Thulasiraj, and R Meenakshi Sundaram Hugh R Taylor 52 NEWS AND NOTICES
COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008 37
C ommunity Eye Health
Journal CHANGING PATTERNS IN GLOBAL BLINDNESS Continued

Figure 1. Proportion of cases of blindness Similarly, the number of people blind from
due to each major cause* trachoma decreased from approximately
Supporting VISION 2020: The Right to Sight
Refractive error 5 million in 1988 to 1.3 million in 2002.
The journal is produced in 18% 8m The SAFE strategy for trachoma control
collaboration with the
World Health Organization Glaucoma has become widely accepted, tarsal rotation
10% 4.5m has been shown to be the preferred
Volume 21 | Issue 67 | September 2008 surgical procedure for trichiasis, and
oral azithromycin has become the
Editor
Elmien Wolvaardt Ellison AMD first-choice antibiotic for mass
7% 3.2m
Editorial consultant for Issue 67 treatment of communities with
Cataract
Dr Paddy Ricard endemic trachoma infection (as
Corneal scar 39%
Editorial committee 4% 1.9m 17.6m shown in the article on page 43). It is
Dr Nick Astbury also highly likely that improvements
Professor Allen Foster Diab. retinopathy
in water supply and sanitation have
Professor Clare Gilbert 4% 1.8m
Dr Murray McGavin significantly reduced the transmission
Childhood
Dr Ian Murdoch of trachoma infection in poor rural
Dr GVS Murthy 3% 1.4m communities in Africa and Asia. However,
Dr Daksha Patel Trachoma
Dr Richard Wormald 3% 1.3m more investigative work is required in order
Dr David Yorston Oncho. Other causes to reduce recurrence after trichiasis surgery
Regional consultants 0.7% 0.3m 11% 4.8m and to identify the most cost-effective
Dr Sergey Branchevski (Russia) *Global numbers shown in millions (m) strategies for the distribution of azithromycin.
Dr Miriam Cano (Paraguay)
Professor Gordon Johnson (UK) blinded by trachoma, onchocerciasis, and
Dr Susan Lewallen (Tanzania) vitamin A deficiency have tended to decrease Onchocerciasis
Dr Wanjiku Mathenge (Kenya) In 1988, onchocerciasis was a significant
over the last twenty years. This is due to
Dr Joseph Enyegue Oye (Francophone Africa) cause of blindness in many countries in Africa.
Dr Babar Qureshi (Pakistan) improvements in nutrition, water supplies,
This same year, however, saw important
Dr BR Shamanna (India) sanitation, and measles immunisation coverage,
Professor Hugh Taylor (Australia) developments in the treatment of the disease:
as well as to the provision of certain therapeutic
Dr Min Wu (China) Merck & Co. had registered the microfilaricide
Dr Andrea Zin (Brazil) medicines: ivermectin (Mectizan®), vitamin A,
ivermectin (Mectizan®) a year earlier and its
and antibiotics. Figure 1 shows the proportion
Advisors Mectizan® Donation Programme came into
Dr Liz Barnett (Teaching and Learning) of cases of blindness due to each major cause,
effect, providing Mectizan® free of charge
Catherine Cross (Infrastructure and Technology) according to the most recent estimates.
Dr Pak Sang Lee (Ophthalmic Equipment) to individuals and communities with
Sue Stevens (Ophthalmic Nursing) onchocerciasis, as shown in the article on
Cataract
Special advisors for Issue 67 page 43. Twenty years on, the severity of
Over the past twenty years, the major
Professor Allen Foster onchocerciasis infection is decreasing and
Professor Clare Gilbert advance in the treatment of cataract has
the number of people developing vision loss
Editorial assistant Anita Shah been the worldwide availability of low-cost,
has markedly decreased. The figures for
Design Lance Bellers good-quality intraocular lenses (IOLs) since
Printing Newman Thomson the early 1990s. Their routine use has 2007 indicate that over 50 million people
are now receiving Mectizan® on an annual
Online edition Sally Parsley resulted in an increase in both the quality of
Email [email protected] visual outcome for patients (as shown by basis through community-directed
Information service population-based rapid assessment of treatment programmes.
Email [email protected]
cataract surgical services)5 and the willingness
Website of surgeons to perform cataract surgery at Childhood blindness
Back issues are available at: an earlier time, before blindness has developed. Although vitamin A deficiency was a well-
www.cehjournal.org
This is detailed in the article on page 40. recognised cause of blindness in children
Subscriptions and back issues There is evidence that, since the intro- twenty years ago, little work had been done
Community Eye Health Journal, International Centre duction of IOLs, there has been an increase up to that time on the magnitude and causes
for Eye Health, London School of Hygiene and Tropical
Medicine, Keppel Street, London WC1E 7HT, UK. in cataract surgical rates around the world, of childhood blindness. The article on page 46
Tel [phone] and particularly in low-income countries.4 presents an overview of the data collected and
Fax [phone] Two other important developments in the the lessons learnt over the past twenty years.
Email [email protected] past twenty years have been the populari- These data show marked variations
The Community Eye Health Journal is published four sation of phacoemulsification and the according to the socio-economic status of
times a year and sent free to applicants from introduction of small incision cataract surgery the community. For example, vitamin A
low- and middle-income countries. French,
Spanish, and Chinese translations are available and (SICS). Both have resulted in a faster and deficiency still occurs in children under five
a special supplement is produced for India (in English). better restoration of visual acuity. With SICS, in years old living in very poor families and, today,
Please send details of your name, occupation, and addition, the cost per operation is also lower. rising food prices worldwide may aggravate
postal address to the Community Eye Health Journal,
at the address above. Subscription rates for applicants Although it is difficult to obtain accurate this situation further. Similarly, retinopathy of
elsewhere: one year UK £50; three years UK £100. figures, it is likely that the global number of prematurity has emerged as a significant
Send credit card details or an international cheque/ cataract operations has increased from problem in middle-income countries and in
banker’s order made payable to London School of
Hygiene and Tropical Medicine to the address above. about 5 million per year in 1988 to around urban centres of the developing world. The
15 million per year now. most important treatable cause of childhood
© International Centre for Eye Health, London
Articles may be photocopied, reproduced or translated provided these Despite these overall positive develop- blindness, however, remains untreated or
are not used for commercial or personal profit. Acknowledgements
should be made to the author(s) and to Community Eye Health Journal. ments, we should not be complacent: poorly treated cataract, which is responsible
Woodcut-style graphics by Victoria Francis.
17 million people are blind today because for 5–20% of all cases.
ISSN 0953-6833
The journal is produced in collaboration with the World Health Organization. they have not yet received cataract surgery.
Signed articles are the responsibility of the named authors alone and do Refractive error
not necessarily reflect the policies of the World Health Organization. The
World Health Organization does not warrant that the information contained Trachoma Little was known in 1988 about the magnitude
in this publication is complete and correct and shall not be liable for any
damages incurred as a result of its use. The mention of specific companies In 1988, it was estimated that 150 million of visual loss due to refractive error. This
or of certain manufacturers’ products does not imply that they are
endorsed or recommended by the World Health Organization in preference children were infected; this number had was due to the fact that the World Health
to others of a similar nature that are not mentioned.
fallen to approximately 84 million by 2004.6 Organization’s (WHO) definition of blindness
38 COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008
h protocols based upon evidence from clinical defi ned focus and strategy.
a
h
a S trials. In appropriate settings, therefore, Estimates of global blindness made
nit there can now be a public health approach in 2002 were 15 million lower than the
A
to the control of visual loss from diabetes.8 projections made for this same year when
VISION 2020 was launched. There is also
Age-related macular degeneration evidence that the number of people who are
(AMD) blind due to onchocerciasis and trachoma
As life expectancy increases, AMD is has decreased, as well as evidence of
becoming a more important problem, not increasing cataract surgical rates in many
only in high-income, but also in middle- countries. Our challenge now is to build on
income countries (see article on page 48). what has been achieved and to focus
A patient collects her spectacles. inDiA
In 2002, it was estimated that 3.2 million resources on the poorest communities in
excluded correctable refractive error, which people were blind from AMD. As yet, there is the world. The goal of VISION 2020 is to
was therefore not recorded in surveys. no proven prevention for AMD although enable all persons to receive eye care and
Since then, some population-based smoking has been shown to be an important have the right to sight – which is one of their
blindness surveys have included people who risk factor. Various surgical procedures are fundamental human rights.
cannot see because they have no spectacles being tried in selected cases and recent
and specifi c surveys have been done to studies indicate that vascular endothelial R1 efFerricekn cKeDs et al. The magnitude and cost of global
assess refractive error in school children. growth factor (VEGF) blockers can delay or blindness: an increasing problem that can be
Figures published in 2008 indicate that, due stop progression of vascular AMD (see alleviated. Am J Ophthalmol 2003;135: 471–6.
2 Resnikoff S et al. Global data on visual impairment
to uncorrected refractive error, there are article on page 50). In spite of promising in the year 2002. Bull World Health Organ 2004;82:
145 million people with VA ranging from recent developments, there is, however, no 844–851.
<6/18 to 3/60 and 8 million people who are proven therapy to reverse the degenerative 3 Resnikoff S et al. Global magnitude of visual
impairment caused by uncorrected refractive errors in
blind (VA <3/60) (see Table 1).3 Spectacles process in all cases and current therapies 2004. Bull World Health Organ 2008;86: 63–70.
have generally become more available and remain expensive.9 4 International Agency for the Prevention of Blindness.
more affordable, but in many countries there SStigahtet 1o9f t9h9e– w2o0r0ld5’s. IsAigPhBt,. LVoISnIdOoNn ,2 2002005: .The Right to
is still a need for good refraction services Making a difference with 5 Limburg H et al. Review of recent surveys on blindness
and visual impairment in Latin America. Br J
and for appropriate dispensing of low-cost
VISION 2020: The Right to Ophthalmol 2008;92: 315–319.
but good-quality spectacles. 6 Mariotti SP. New steps toward eliminating blinding
Sight trachoma. N Engl J Med 2004;351(19): 2004–7.
7 Quigley HA et al. The number of people with glaucoma
Glaucoma In 1988, the WHO Prevention of Blindness worldwide in 2010 and 2020. Br J Ophthalmol
During the last twenty years, work has been (PBL) programme and the International 2006;90: 262–7.
undertaken to develop improved defi nitions Agency for the Prevention of Blindness 8 World Health Organization. Prevention of blindness
from diabetes mellitus. WHO, Geneva, 2006.
and classifi cations of glaucoma. This has (IAPB) had been in existence for ten years. 9 Andreoli CM et al. Anti-vascular endothelial growth
allowed for better estimates to be made of Over the next decade, several important factor therapy for ocular neovascular disease. Curr Opin
Ophthalmol 2007;18: 502–8.
the number of people with this condition.7 developments made it possible to conceive
It is likely that the current global estimate of of a global initiative to eliminate avoidable
Twenty years of Mectizan®
4.5 million people blind due to glaucoma blindness: the Mectizan® Donation
actually falls short of the true fi gure, as many Programme was established in 1987, Donation Programme
surveys do not include an assessment of low-cost IOLs became available in the early
visual fi eld loss and are limited to a defi nition 1990s, and the SAFE strategy was launched ers
oGfl obblianldlyn, e6s0s mbailslieodn opneloyp olen avirseu laikl ealcyu tioty h. ave ibne 1tw9e9e6n. vInit aamddinit iAo nd,e tfih ceie rneclayt iaonnds hcihpi ldhood Sightsav
one of the glaucomas and up to 8 million mortality had already been documented. ay/
d
may be blind because of this disease. Drawing on their experiences of cost- un
S
Because no simple, specifi c, and sensitive effective eye care delivery systems in several on
test exists for this condition, population-based countries in the 1980s and 1990s, including nd
a
screening cannot at present be advocated; in India and The Gambia, a group of non- Scotl
opportunistic case detection should, governmental development organisations n/
o
hmoawneyv leorw, b- ea nedn cmoiudrdalgee-idn.c Uomnfeo rctuonuantteriley,s ,in (VNISGIODNO s2),0 t2o0g:e Tthheer Rwigithht t thoe S WigHhOt ,in la 1u9n9ch9e. d Wilkins
effective treatment for glaucoma is still out This is a global initiative to eliminate Phil
of reach: medical treatment requires the avoidable blindness from cataract,
availability of affordable drugs and long-term trachoma, onchocerciasis, refractive error,
patient compliance; surgical treatment vitamin A defi ciency, and other causes of
requires patient acceptance, as well as blindness in children by the year 2020.
surgical skill, experience, and the capacity The World Health Assembly has since
for long-term follow-up. This is diffi cult to adopted resolutions urging its member
achieve in some settings. states to adopt the VISION 2020 principles.
More than 90 NGDOs, agencies, and
Diabetic retinopathy institutions, together with a number of
In 1988, there were no data on the global major corporations, are now working
prevalence of diabetic retinopathy or of together in this global partnership.
blindness resulting from this condition. It is There is little doubt that the VISION 2020 2007 marked the 20th anniversary
now estimated that there are approximately initiative has raised awareness concerning of the Mectizan® Donation Programme.
171 million people with diabetes worldwide. blindness and the cost-effectiveness of Since 1987, over 2 billion tablets of
Of these people, probably 10–20% have some available interventions. It has mobilised Mectizan® (ivermectin) have been
form of retinopathy and around 1.78 million both government and private funding for eye donated by Merck to more than
are blind. There are now better-defi ned care and it has generated a global public- 30 countries to fi ght onchocerciasis
screening procedures and agreed treatment private partnership working with a clearly
Copyright © 2008 Allen Foster, Clare Gilbert and Gordon Johnson. This is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
CATARACT SURGERY
Cataract surgery at
Aravind Eye Hospitals: 1988–2008
G Natchiar number of cataract operations it performs ah
h
Vice Chair & Director – Human Resources, annually: from a total of 29,928 in 1988 to a S
Aravind Eye Care System, Anna Nagar, 180,991 operations in 2007, performed at nit
A
Madurai 625 020, Tamil Nadu, India. the five centres.
RD Thulasiraj During the last two decades, over 70% of
Executive Director, Lions Aravind the cataract operations on poor patients
Institute of Community Ophthalmology, have been performed free of charge or at a
Aravind Eye Care System; Past heavily subsidised rate; the other 30% have
President, VISION 2020: The Right been conducted in the separate paying
to Sight: India. section, on patients who could afford the
regular fee.
R Meenakshi Sundaram
Senior Manager – Outreach, Aravind
Transition in cataract Older patients are welcomed at a
Eye Care System.
screening camp. inDiA
services: 1988–2008
at the camp site ranged from four to seven
In the 1980s, cataract was the major cause Community outreach
days. Patients had to lie down with their eyes
of blindness in India and was responsible for From the day the hospital opened its doors
bandaged in a complete resting position to
80% of all blindness.1,2 This prompted the in 1976, Aravind has been organising
avoid wound leak or iris prolapse, and they
Indian government to launch a national community outreach, always with the
were given soft food to eat. The operated
cataract control programme, which involvement of the local community. This
patients were issued standard +10 D aphakic
succeeded in lowering the prevalence partnership has led to widespread
spectacles at the time of discharge and
of blindness from 1.49% to 1.1%.2,3 awareness of cataract services across the
were advised to come for follow-up at the
In addition, by 2000, this programme had state of Tamil Nadu. Today, the same
base hospital or camp site a month later.
reduced the proportion of people blind due strategy is being used successfully to create
We reduced the number of surgical eye
to cataract from 80% to 62%.4 awareness about other conditions, such as
camps over the years and, in 2002, we
Aravind Eye Hospitals contributed to a diabetic retinopathy, refractive error, and
completely stopped organising them, as the
third of all cataract operations in the state of childhood blindness, and to address them.
growing network of Aravind Eye Hospitals
Tamil Nadu during the last two decades and In the late 1970s, surgical eye camps
provided easy access for the community in
played a major part in lowering the rate of were in vogue in India. During this era, in
each service area. Screening eye camps,
blindness in that state. By 2000, the preva- addition to the hundreds of screening
however, continue to this day; the patients
lence level of blindness was just 0.78%, camps it held, Aravind Eye Hospital
brought in from these camps account for
compared to the national level of 1.11%.3 organised a few surgical eye camps, which
over 50% of the cataract operations
The first Aravind Eye Hospital was proved to be very resource intensive. In
performed in the five Aravind Eye Hospitals.
founded in 1976 and contained just these surgical camps, operations were
11 beds. There are now five Aravind Eye performed at the site, which could be a
Indications for cataract surgery
Hospitals, located up to 500 km apart, school, a college, a community hall, or a
In 1988, the selection criteria for cataract
which form part of Aravind Eye Care System local hospital. At that time, intracapsular
surgery was best corrected visual acuity (VA)
(AECS). Over the last two decades, the cataract extraction (ICCE) was the chosen
of <6/60. In the 1990s, as new surgical
organisation has increased six-fold the surgical procedure. The postoperative stay
techniques started to result in better visual
rehabilitation, the criteria changed to
h
a
h include patients who, due to cataract, found
S
nita it difficult to perform their daily tasks. This
A marked a shift away from clinical criteria
and towards more patient-centred criteria.
In addition, more and more patients are
spontaneously coming for early surgery
before they become blind, since cataract
operations now have very good outcomes.
Quality assurance
In the 1980s, since only patients with a
preoperative vision ranging from light
perception to VA <6/60 were selected,
patients were very happy with their
postoperative vision, in spite of the limita-
tions of the aphakic spectacles they were
given. Nowadays, as patients with much
better preoperative vision are being admitted,
it has become essential to assess the quality
of postoperative vision as well. In addition to
quantitative visual acuity assessment,
patients are also asked how satisfied
they are with their vision. Amongst other
The Aravind Eye Hospital in Madurai. inDiA things, this helps to refine postoperative
40 COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008
refractive error correction by Athis type of surgery. In addition,
DI
gpeatttieinngt sa’ beexptteecrt saetinosnes ;o ift tahles o ers. INtnreaedditeiodn taol obpee arsasteinsgs epdra acntidc es
av
helps in explaining to patients htsimproved, if necessary.
about the vision recovery process Sig In 1992, AECS established
and what to expect. This improved ws/Aurolab, a local non-profit trust,
e
h
vision assessment is a reflection attwith the support of the Seva
M
of the modern lifestyle in India, ny Foundation, Combat Blindness
which demands a much better enFoundation, and Sightsavers
J
quality of vision.5 International. Aurolab undertook
At Aravind, surgical complica- the task of producing low-cost IOLs.
tions and the outcomes of every These were initially sold for US $10
operation have been monitored each. The price of the IOLs
since 1991, using continually produced by Aurolab steadily
evolving software, to enhance declined as efficiency and demand
quality by analysing visual increased; at present, the cost of
outcomes, infections, complica- rigid polymethyl methacrylate
tions, and the number of patients (PMMA) IOLs stands at around
needing a second operation on the US $2. These have been made
same eye. This has helped put in available in over 120 developing
place a system of continuous countries. The trust also started to
improvement.6 For example, out of produce sutures, pharmaceuticals,
73,323 cataract operations and other surgical supplies locally.
performed in 2007 at the Aravind This has helped to bring down the
Eye Hospital in Madurai, the rate of cost of cataract operations further
surgical complication was 1.6%, in India and elsewhere.
the rate of postoperative infection In 1994, Aravind introduced
was 0.05%, and corrective surgery phacoemulsification. Considering
was needed on the operated eye in the very good outcome of this new,
0.4% of cases. sutureless IOL technique, Aravind
The decision, in 1992, to locally produce high- promoted it very intensively
High-volume cataract quality IOLs and the introduction of manual SICS amongst the paying patients who
techniques in 1998 have contributed to much could afford the additional cost.
surgery
greater satisfaction amongst patients, both paying The development of the manual,
Aravind’s success at performing a and non-paying sutureless, small incision cataract
large number of cataract operations surgery (SICS) represented another
per year and per surgeon (known as great stride towards offering IOL
high-volume cataract surgery) is felt strongly that every villager undergoing cataract surgery to more patients. SICS is
based on three main pillars: cataract surgery should get an IOL implant. cheaper, quicker, and easier to perform, and
He understood how difficult it was for these its outcomes compare very well with that of
• making intraocular lenses more people to carry out farm work with aphakic phacoemulsification. In 1998–1999, we
affordable spectacles. The major obstacles to offering introduced this technique at Aravind in both
• training cataract surgeons IOL implantation to everyone were the high the ‘free or subsidised’ and paying sections
• developing good systems of service cost of IOLs and the fact that there were not (see Table 1).
delivery (as described above), as well as enough ophthalmologists trained to perform Continues overleaf ➤
innovative operating practices (the
‘assembly line’ system, described below). Table 1. Surgical techniques used for cataract operations over the last two decades at
Aravind Hospitals
Making intraocular lenses more
year Patient category Total Surgical technique
affordable
no. of
Although ICCE was the standard procedure Cataract surgery Cataract surgery
cataract
at Aravind at the time, some surgeons had with iOL without iOL
operations
started to use ‘iris clip’ intraocular lenses (% in each section) (% in each section)
(IOLs) in the paying section as early as 1979;
Paying section 8,763 41% 59%
a total of 20 such lenses were used in that
1988
year. A switch to anterior chamber IOLs was Free or subsidised section 21,193 4% 96%
made in 1981 and, by the mid-1980s,
All patients 29,956 15% 85%
surgeons started to use posterior chamber
lenses regularly. Paying section 30,696 96% 4%
IOLs were however very expensive 1998
(imported at US $100 each in the mid-1980s) Free or subsidised section 100,480 88% 12%
and these operations could only be offered
All patients 131,176 90% 10%
in the paying section. The hospital therefore
could not afford to give them away free or at 2007 ECCE with SiCS with Phaco
low cost to poorer patients. For the same iOL* iOL with iOL
financial reasons, international non-
Paying section 53,107 4% 23% 73%
governmental development organisations
(NGDOs), as well as the Indian government, Free or subsidised section 127,884 15% 82% 3%
did not support IOL surgery at the time.
All patients 180,991 12% 65% 23%
However, Dr G Venkataswamy, the
founder of Aravind Eye Hospitals and AECS, *Less than 1% of cataract operations are performed without IOL
COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008 41
CATARACT SURGERY Continued
Table 2. Worldwide distribution of Aravind trainees by World Health Organization Regions
Current practice
Europe Americas South Africa Western Eastern at Aravind
East Asia Pacific Mediterranean
Candidates In the paying section:
trained at • Around 75% of cataract operations are
Aravind in performed using phacoemulsification,
IOL surgery 91 10 1,353 38 101 29 mostly with foldable lenses. Many of
the patients go home within two hours
Table 3. The impact of operating equipment and support staff on the number of cataract
of surgery. A total of 80% of operations
operations a single surgeon can perform in one hour at Aravind Eye Hospitals
are performed under topical anaesthesia.
• Around 25% of operations are done
Operating Scrub nurses Running instrument Operations
using manual, sutureless small incision
tables nurses sets per hour
cataract surgery (SICS) techniques
1 1 1 1 1 (usually when the nucleus is very hard).
• Less than 5% of operations are done using
1 1 1 2 2
extracapsular cataract extraction (ECCE)
2 2 1 6 6–8 when phacoemulsification or SICS are
contraindicated.
Training cataract surgeons capacity of the surgeons
To address the challenge of developing the • ensuring that all surgical supplies are In the ‘free or subsidised’ section:
skills required for microsurgery with IOL available and that equipment is in good • 80% of walk-in patients and those
implants, AECS designed and started the working condition. referred from eye camps are operated
Micro Surgery Training Programme in 1993, Each day of surgery is planned meticulously in using manual, sutureless SICS techniques.
with support from Sightsavers International. advance. This includes planning the number Patients go home either on the same
To promote high-quality and high-volume of surgeons and nurses needed, as well as day or the next day, depending on the
cataract surgery, Aravind also published a the number of IOLs and other surgical supplies distance they need to travel. These
series of manuals, such as the Quality required. On the day of his/her operation, operations are done under peribulbar or
Cataract Series in 2001, the Manual on SICS the patient receives the prescribed local retrobulbar anaesthesia. This has
technique in 2000, and the Manual for IOL anaesthesia and is then led to the operating increased the productivity of surgeons
trainees in 2001. room, where each surgeon has two operating and brought down the cost of surgery.
As of August 2008, a total of 1,622 trainees tables. The patient is draped and prepared • In cases where SICS is not possible,
from 44 countries have been trained at on one table, while the surgeon is operating ECCE with IOL is performed.
Aravind: 1,132 in ECCE, 310 in SICS, and
on the other table, on a patient admitted • Almost 99% of cataract operations are
180 in phacoemulsification (see Table 2).
earlier. On completing the operation, the performed with IOL.
surgeon swings the arm of the microscope
Developing innovative operating
over the next table, follows the prescribed
practices lenses by AECS and the establishment of a
asepsis protocol, and then begins surgery on
In order to ensure a high volume of cataract training programme for ophthalmologists
the new patient. Table 3 illustrates how the
operations, while keeping the quality of have also increased the number of high-
productivity of a single surgeon increases
surgery high, it is vital to use the time of the quality cataract operations performed
according to the availability of operating
ophthalmologist as effectively as possible. worldwide. This is particularly true in
equipment and support staff.
Indeed, ophthalmologists are probably the developing countries, where costs were
most expensive and scarce resource prohibitive before the introduction of
Conclusion: the impact of
needed to perform a cataract operation. low-cost IOLs.
Aravind developed specific practices to the Aravind model Aravind has shown that cataract opera-
increase the volume of cataract operations. The developments described in this article tions can be done on a massive scale, while
These are known as the ‘assembly line’ system have all played a major role in increasing the still providing quality care. Previously, there
and consist of the following three elements: cataract surgery rate in Tamil Nadu (from was one kind of surgery for the upper classes
• setting up an efficient patient flow 2,039 in 1988–9 to 7,633 in 2005–06), and another for the masses. History has
• organising the operating equipment and in India as a whole. shown that, with appropriate technology and
and support staff to match the output The production of cheaper intraocular processes (the assembly line system, locally
made IOLs and consumables, and locally
m trained surgeons), it is possible to duplicate
e
Syst developed world results at an affordable cost.
e
ar
C
e References
d Ey 1 Mohan M. Collaborative study on blindness (1971-1974):
n a report. Indian Council for Medical Research, New
Aravi Delhi, 1987.
2 Mohan M. Survey of blindness – India (1986-1989).
Ministry of Health & Family Welfare, Government of
India, New Delhi, 1989.
3 Murthy GVS et al. (eds). National survey on blindness &
visual outcomes after cataract surgery (2001–2002):
report. National Programme for Control of Blindness,
Ministry of Health & Family Welfare, Government of India,
New Delhi, 2003.
4 Murthy GV et al. Current estimates of blindness in India.
Br J Ophthalmol 2005;89: 257–60.
5 Fletcher A et al. The Madurai Intraocular Lens Study III:
Patients discharged from a Visual Functioning and Quality of Life Outcomes.
Am J Ophthalmol 1998;125(1): 26–35.
surgical camp are given food
6 Thulasiraj RD et al. The Sivaganga Eye Survey: II.
before they return home. inDiA Outcomes and cataract surgery. Ophthalmic Epidemiol
2002;9(5): 313–324.
Copyright © 2008 G Natchiar, RD Thulasiraj and R Meenakshi Sundaram. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
ONCHOCERCIASIS AND TRACHOMA
Onchocerciasis and trachoma control:
what has changed in the past two decades?
Daniel Etya’ale Navailable at the time, would lend
O
Coordinator of VISION 2020 ROthemselves to further extension of
E
in Africa, Programme for the AMcontrol activities to the other
PWroervledn Htieoanl tohf OBrlginadnnizeastsio, n, avers. Cesinxd ine mCeicn ctroaul natnride sL a(1tin9 Ainm Aefrriiccaa) a.1nd
20 Avenue Appia, CH-1211 hts All this changed in 1987 with
Geneva 27, Switzerland. er/Siga first and historic donation of
Trachoma and onchocerciasis are ortivermectin (Mectizan®) by Merck &
P
the two major infectious causes of ne Co.2 For the first time, a safe and
n
blindness worldwide. Twenty years uzaeffective microfilaricide was not only
S
ago, the possibility of achieving available, but, as subsequent
worldwide and long-term control of studies quickly established, could
these ancient scourges seemed lend itself to mass treatments in
remote and existing control high-risk, endemic communities.
programmes were deemed to have The wide and generous availability
limited prospects. The picture is of Mectizan® also accelerated
very different today: large-scale operational research activities and
interventions to control both the development of new tools – for
diseases are not only expanding, example Rapid Epidemiological
but control and even elimination are Mapping of Onchocerciasis (REMO)
now being discussed as real was developed to precisely map
achievable goals in a growing all priority areas in each endemic
number of countries. As we will show country3 and it emerged that
in this mainly programmatic review, Community-Directed Treatment
this is a remarkable achievement with Ivermectin (CDTI) was the most
over only two decades! appropriate and cost-effective
method for community-wide
From slow and delivery of the new drug. CDTI was
advocated when the African
uncertain beginnings
The donation of Mectizan® by Merck & Co from 1987 Programme for Onchocerciasis
to large-scale efforts has had a unique impact on the worldwide fight Control (APOC) was launched in 1995,
against onchocerciasis and it remains the current strategy
Onchocerciasis
of all programmes today. In addition,
Up until the late 1980s (see Table 1),
CDTI is now being used to distribute
the only established disease control strate that control of onchocerciasis as a
other public health interventions such as
activity was the Onchocerciasis Control public health problem was indeed possible.
vitamin A and bednets to prevent malaria.
Programme (OCP), a World Health However, many thought this concerned only
Looking back, this historic and still unsur-
Organization (WHO) programme jointly 11 countries. Moreover, neither the strategy
passed donation of Mectizan®, “to as many
sponsored by the World Bank, the United (vector control), nor the tools developed by,
as need it, for as long as needed,” is the
Nations, and a coalition of over 20 donor and for, OCP operations (weekly aerial appli-
one essential ingredient that has uniquely
countries and agencies. Set up in 1974 in cations of larvicide, ongoing monitoring of
impacted nearly every major development in
seven, then 11, countries in West Africa, community microfilarial loads and flies’
the worldwide fight against onchocerciasis
OCP was the first programme to demon- infectivity, etc.), nor the financial support
since then. It has also inspired other major
Table 1. A chronological outline of the development of onchocerciasis control drug donation initiatives, such as that of
programmes since 1974 albendazole by GlaxoSmithKline in 1998 for
lymphatic filariasis, and that of azithromycin
Date Key event
by Pfizer Inc. for trachoma the same year.
1974 • OCP is established in West Africa, using vector control as the sole strategy
Trachoma
1987 • Mectizan® Donation Programme is launched
Modern efforts to control trachoma date
1989– • Large community-scale trials show the benefit of Mectizan® back to the early 1950s, with the estab-
1990 • First NGDO-supported Mectizan® distribution projects, using mobile strategies lishment, through WHO’s support, of
national programmes in endemic countries
1992 • The NGDO Group for Mectizan® distribution is established within the WHO
in the Western Pacific, Asia, and the Middle
Prevention of Blindness Programme
East (see Table 2). These activities also
• OEPA is launched
included the assessment of the magnitude
1994 • REMO is developed to define priority areas for disease control of blinding trachoma in these regions and
the institution, where feasible, of operational
1995 • CDTI is recommended as a safe and cost-effective strategy for
research on treatment options. However,
onchocerciasis control
these efforts were rarely sustained. This was
• APOC is launched
due partly to the lack of a simple tool to
1999 • VISION 2020 is launched assess and grade trachoma and to the
nearly insurmountable challenge of
2002 • OCP winds down its activities
Continues overleaf ➤
COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008 43
ONCHOCERCIASIS AND TRACHOMA Continued
Table 2. A chronological outline of the development of trachoma control programmes 40 million people from ocular morbidity
since the mid-twentieth century throughout large areas in West Africa.
However, it was also agreed that in order
Date Key event
to prevent recurrence of the disease and
1950s and 1960s • Establishment of National Trachoma Control Programmes, mainly in consolidate these important gains,
endemic Asian, Middle Eastern, and Western Pacific countries distribution of Mectizan® must be
continued, with high coverage, and robust
1987 • Introduction of the simplified grading scheme for trachoma
surveillance systems established and
1996 • Introduction of the SAFE strategy maintained.
Elsewhere, control activities now cover
1997 • Launch of GET 2020 nearly all known meso- and hyper-endemic
areas around the world. APOC thus aims to
1998 • First donation of azithromycin and establishment of the International
protect some 92 million at-risk individuals
Trachoma Initiative
from the deleterious effects of river
1999 • Launch of VISION 2020 blindness; currently more than half of them
are under annual Mectizan® treatment.
fostering community-wide compliance for a providing the mandate and framework for Similarly, the Onchocerciasis Elimination
six-week treatment regimen of twice-daily trachoma control worldwide; (ii) the donation Programme for the Americas (OEPA) has
application of a tetracycline ointment, in the of azithromycin by Pfizer Inc. in 1997; and established, in all six endemic countries,
absence of parallel measures to transform (iii) the subsequent establishment in 1998 effective national programmes in all 13 foci
at the same time the environment in which of the International Trachoma Initiative (ITI), with a treatment coverage of at least 85%
trachoma thrives. As a result, trachoma to manage this donation. This served as a twice a year. Even more significantly in 2007,
attracted only marginal public interest until catalyst to expand and accelerate ongoing all eye lesions attributable to onchocerciasis
the mid-1990s.4 control activities, a process further facili- had been eliminated in nine of these 13 foci.
The introduction of the simplified grading tated by the ease with which azithromycin
scheme for trachoma in 1987 and of the can be administered even on a large scale Trachoma
SAFE strategy (Surgery, Antibiotics, Facial (a single oral dose in most cases, as opposed An increasing number of endemic
cleanliness and Environmental changes) in to the six-week tetracycline regimen). countries are now receiving support for
1996 by WHO5 represented crucial opera- baseline surveys, national plan devel-
tional milestones in trachoma control. This Some major achievements opment, the implementation of the
led to three important developments, which SAFE strategy, and the development and
to date
provided the impetus needed to put this use of appropriate indicators for monitoring
ancient disease back on the world map in Onchocerciasis and evaluation purposes. Others, like
the mid-1990s: (i) the establishment of the OCP wound down its activities in 2002, having Morocco, the first country to have
WHO GET 2020 alliance (Global Elimination achieved the prevention of 600,000 cases completed its campaign for trachoma
of Blinding Trachoma by the Year 2020), of blindness and protected a further control in 2006, are now awaiting WHO
Ten reasons for success
The rapid progress and success achieved so far by onchocerciasis and trachoma control programmes
is due to a combination of many contributing factors. These include:
1 Drug donations by pharmaceutical 5 Secure and predictable financing 9 A flexible and adaptive approach
companies: the historic, generous and over many years ensuring that planned to mass distribution: e.g. mass
timeless donation by Merck & Co. of activities will indeed be implemented: distribution of Mectizan® has
Mectizan® for onchocerciasis control 27 years for former OCP; ongoing since evolved from mobile strategies (very
activities, and Pfizer Inc.’s donation of 1992 and 1995, respectively, for OEPA expensive and hardly sustainable)
azithromycin for trachoma control in a and APOC. to community-directed treatment with
number of affected countries. 6 The establishment of a solid public- ivermectin (high community
2 The development of cost-effective, private partnership and the meeting ownership, very cost effective, and
rapid assessment methodologies once a year of all stakeholders more likely to be sustainable).
which facilitated the mapping of the to review past and future programme 10 Active involvement of target
disease, such as: REMO (Rapid activities and more importantly, to communities: the prime benefici-
Epidemiological Mapping of agree on next year’s budget for the aries of the programme, i.e.
Onchocerciasis) and REA (Rapid programme.
affected communities, are actively
Epidemiological Assessment) for
7 The existence in each endemic involved at all stages of programme
onchocerciasis, or the simplified grading
country of well-structured and truly implementation (planning, community
scheme for trachoma, which facilitated
functional national Onchocerciasis mobilisation, motivation of distrib-
the identification of priority areas.
Task Forces (NOTF), in which all stake- utors, implementation, supervision,
3 Development of country databases holders (programme managers, NGDOs, monitoring – including self-monitoring
for planning, monitoring and evalu- Ministry of Health officials, researchers) and supervision). A sharp contrast
ation: extensive, user-friendly, interactive meet regularly to plan, implement, to what still prevails in many health
databases, with detailed information on monitor, and evaluate together all intervention programmes, where
all endemic communities, target ongoing control activities. targeted populations have no other
populations, nearby schools and health 8 The promotion, generous support and role to play except that of passive
facilities, roads, etc. regular use of operational research but grateful participants of well-
4 Regular maintenance and updating on all core aspects of programme designed and scientifically sound
of these databases in each country implementation and its ‘feedback’ into programmes developed on their
by well-trained and capable local teams. ongoing operations. behalf and for their benefit.
44 COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008
certification for the elimination of MALI common. Both are diseases of
bhleinadltihn gp rtorabclehmom thar oaus gah pouubt ltihc e Buchan. pthoev eprotyo,r oefstte anm aoffnegc ttihneg pnooot rj,u bstu t
cGoaumnbtriya., O Gthhaenr ac,o Munaturireitsa sntiiall, ( aThned John acolsmo mthuen mitioesst odfitfefinc udlet stoc rriebaecdh a isn
Viet Nam) are also well on track to “at the end of the road.” The
completing their trachoma control challenges that they pose for their
campaigns by 2010. control are also quite similar, in
that successful control of both
Future prospects diseases requires far more than
an effective strategy or a freely
There is little doubt that, because
available drug. Just as essential is
of ongoing activities and the
highly coordinated work between
remarkable achievements to
all players involved, from donors
date, onchocerciasis and blinding
and researchers, to people
trachoma may become the
working in the field, not forgetting
first major causes of needless
affected communities themselves.
blindness to achieve VISION 2020
Trachoma control presents us
objectives within the year
with an additional (and major)
2020 endpoint.
operational challenge, in that the
APOC’s operations are now
success of the SAFE strategy
scheduled to end by 2015.
requires a close and essential
Current thinking and consensus is
collaboration with non-medical
that, by then, the primary
experts for the implementation of
objective of the Programme, i.e.
its ‘F’ and ‘E’ components. Failing
to establish sustainable national
to fully implement all of its four
onchocerciasis control activities
components will mean running
in all endemic countries, may not
the risk of reducing the SAFE
be achieved everywhere. This is
strategy into a purely medical
mainly because programme effort that, most agree, is not
implementation has been signifi- likely to achieve optimal success
cantly slowed down in war-torn – if at all – in our fight against
countries, for obvious reasons, blinding trachoma.
and in Central Africa where
co-endemicity with Loa Loa and The SAFE strategy, introduced in 1996, was one of References
1 World Health Organization. Onchocerciasis
the risk of severe Central Nervous the events that put the fight against trachoma back
and its control. Report of a WHO Expert
System complications has on the map Committee on Onchocerciasis.
required extreme care and close Technical Report Series No. 852.
WHO, Geneva, 1995.
medical supervision in the distri-
SAFE strategy and an increasing number of 2 Thylefors B. Eliminating onchocerciasis as a public
bution of Mectizan®. health problem. Trop Med Int Health 2004;9(4):
It is therefore imperative to ensure that all endemic countries with fully developed A1–A3.
national plans. Hopefully, both developments 3 Noma M et al. Rapid epidemiological mapping of
residual activities, including post-treatment onchocerciasis (REMO): its application by the African
will be matched with a similar increase in
surveillance, will have the financial and other Programme for Onchocerciasis Control (APOC). Ann
logistic support needed for their completion financial resources available at country level. Trop Med Parasitol 2002;96(suppl 1): 29–39.
4 Mariotti SP et al. Trachoma: Looking forward to global
or, failing that, for their integration into viable elimination of trachoma by 2020 (GET 2020). Am J
Conclusion
national health care systems. Trop Med Hyg 2003;69(5 suppl): 33–35.
Regarding trachoma control, the coming Despite being two very different diseases, 5 Kuper H et al. A critical review of the SAFE strategy for
the prevention of blinding trachoma. Lancet Infect Dis
years should see a further expansion of the onchocerciasis and trachoma have a lot in 2003;3(6): 372–381.
A challenge for the future: moving out of our comfort zone
Past experience has consistently shown trachoma and public health experts have greater challenge than any other cause of
that medical personnel tend to implement shown limited willingness for, and avoidable blindness. The imperative to
only the S (Surgery) and A (Antibiotic) experience with, such a close and syner- make it succeed leaves us with no other
components of the SAFE strategy. gistic collaboration with non-medical option but to move out of our comfort zone
Reasons for this include: experts. and to proactively seek and reach out to
other players, whose contribution to our
• The ‘S’ and ‘A’ components are the ones While there is no doubt that the ‘S’ and ‘A’
global success may turn out at the end to
that health workers are most comfortable components remain important and urgent,
be the ‘essential one’.
with or have skills for. the natural history of trachoma, in those
• The Ministry of Health rarely has the parts of the world where it was once A humbling challenge indeed for
skills, expertise, and resources needed endemic, is also there to remind us that some, but also a unique opportunity to
for the effective implementation of the the disappearance of the disease had little develop tomorrow’s leaders, many of
‘F’ and ‘E’ components. to do with effective medical intervention whom will be operating more and more
• The ‘F’ and ‘E’ components require input (nonexistent at the time), but everything to (and not less) in resource-constrained
from, and a close working relationship do with improved socioeconomic living environments, involved in more and
with, experts in the fields of education, conditions, better sanitation, easy access more complex interventions such as,
community development, water, to water, etc. the Millennium Development Goals or
sanitation, and hygiene. Seen in that light, trachoma control the co-implementation of Neglected
• To this date, in many endemic countries, presents to medical professionals a far Tropical Diseases.
Copyright © 2008 Daniel Etya’ale. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
CHILDHOOD BLINDNESS
Twenty years of childhood blindness:
what have we learnt? O
G
O
oss. T
Cr
Clare Gilbert for countries where these data were not ed
R
Professor, International Centre for Eye available, which was based on the associ- an
Health; Medical Advisor, Sightsavers di
ation between under-five mortality rates and a
n
International, UK. a
the prevalence of blindness in children. This m/C
MClionhicaaml Rmeseeda rMchu hFeitllow, International mreecethnotd p iosp sutillal tbioenin-gb ausseedd ,s ausr vdeaytsa cfroonmfir mmo re okic.co
Centre for Eye Health, UK. that the prevalence of blindness in children o-k
and under-five mortality rates correlate mark
Over the last 20 years, much has been reasonably well. Under-five mortality rates ww.
w
achieved in controlling blindness in children. are also being used as a proxy indicator of
Prior to the launch of VISION 2020, a number vitamin A deficiency in children.2
of international initiatives and programmes In 1990, experts agreed that corneal
had raised the profile and increased inter- scarring, mainly from vitamin A deficiency
ventions for child health and survival, which and measles, was the major cause of
also had a positive impact on eye diseases childhood blindness in most low-income
and blindness in children, e.g. the Expanded countries.1 However, as a simple classifi-
Programme for Immunisation (EPI )(1974) cation of causes did not exist, the As a result of intense efforts to
and the Global School Health Initiative International Centre for Eye Health (ICEH)
reduce under-five mortality
(1995). Since 2000, the United Nations’ worked with WHO to develop a new system
rates over the last 20 years, the
Millennium Development Goals have for classifying the causes of blindness in
prevalence of corneal blindness in
emphasised the need to promote child children, which was published in 1993.3
children has declined
health and survival. Data collected using this system, which has
Since VISION 2020 was launched in clear definitions, a standard recording form,
1999, controlling blindness in children has and a data analysis package, is being used today, such as those living in urban slums
been a high priority. Child Eye Care Centres to compile a global database of causes.4 and poor communities in rural areas.
are being established with well-trained, In 1997, it was estimated that 45% of blind Measles immunisation is another large-
well-equipped teams, particularly in Asia. children were blind from avoidable causes scale public health intervention to reduce
Programmes for detecting babies with retin- and that the pattern of causes varied child morbidity and mortality. Since the
opathy of prematurity (ROP) are expanding in widely between and even within countries.4 launch of EPI in 1974, coverage with
Latin America, India, China, and other The following conditions were prioritised for measles immunisation has increased to
countries in Asia. Many school-going children control: corneal scarring, cataract, retinopathy target levels in most regions. The numbers
are having their visual acuity measured and of prematurity, refractive error (mostly of measles cases and measles-related
those with refractive error are being provided myopia), and low vision.5 Other studies deaths have declined as a consequence.
with spectacles. Finally, there is improved have shown that most blind children are Measles epidemics are now relatively rare
availability of affordable consumables and either born blind or lose their sight before and measles-related corneal blindness has
equipment, such as paediatric low vision their sixth birthday. Novel methods have also declined. As with vitamin A deficiency,
devices, small diameter intraocular lenses, also been developed which can provide there are still communities of children at
and spectacles for children. important information on the prevalence risk, particularly in sub-saharan Africa,
This article presents an overview of what and causes of blindness in children, such where the majority of measles cases and
we have learnt over the past twenty years as the use of local volunteers who act as measles-related deaths now occur.
and outlines some of the challenges we still key informants.6 There is no reason to be complacent, as
have to face in order to control avoidable there is evidence that under-five mortality
blindness in children and adequately 2 Vitamin A deficiency and measles rates are no longer declining at the same
support those with incurable visual loss. During the 1980s, it was realised that rate as in earlier decades in the poorest parts
vitamin A deficiency was an important cause of the world. Our role as eye care profes-
1 Magnitude and causes of child mortality and that high-dose vitamin sionals is to advocate for children – when we
In 1988, there was little information on the A supplementation significantly reduced see a child with corneal ulceration from
magnitude and causes of blindness and child deaths, even in communities with low vitamin A deficiency or following measles, we
visual impairment in children. At that time, levels of clinical xerophthalmia. Intermittent should not only treat the child, but we should
most of the information on causes had high-dose vitamin A supplementation is an also inform the relevant authorities so that
come from examining children in schools for important public health intervention and they can improve their programmes.
the blind and prevalence data were very approximately 500 million doses are given
limited. However, we have since made annually throughout the world at a cost of 3 Cataract in children
substantial progress, both in collecting data approximately US $1 per dose. As a result, Because corneal blindness is declining in
and in finding ways to estimate the magnitude the prevalence of vitamin A deficiency has many countries in Africa and Asia, cataract
and causes of childhood blindness. declined in many regions of the world. There is becoming a relatively more important cause
In 1990, the World Health Organization is also evidence that blindness in children of avoidable blindness. The management of
(WHO) organised the first meeting of experts due to corneal scarring has also declined. cataract in young children has changed
on the prevention of blindness in children; For example, in Uganda, 53% of all blind dramatically over the last 20 years. When
they estimated that there were 1.5 million children born between 1951 and 1965 intraocular lenses (IOLs) were first used in
blind children in the world.1 In 1997 WHO were blind from corneal scarring, compared the late 1970s, they were thought not to be
held a second meeting, during which the with 14% for children born between 1980 suitable for children. Over the last decade,
estimate was revised to 1.4 million: a new and 1995.7 However, some communities smaller, high-power IOLs, suitable for
method was used to estimate the magnitude are still affected by vitamin A deficiency children, have become available; surgical
46 COMMuniTy EyE HEALTH JOuRnAL 20TH AnniVERSARy EDiTiOn | VOL 21 iSSuE 67 | SEPTEMBER 2008