Download Magnitude and Causes of Childhood Blindness and Severe Visual

PROJECT REPORT
Candidate Number: 490196
MSc CEH
Title:
Magnitude and Causes of Childhood Blindness and Severe Visual
Impairment in Sekoru District of Jimma Zone, South West Ethiopia:
The Key Informant Method.
Supervisor: Dr Anthony Solomon
Word Count: 8,238
Project Length: Standard
Submitted in part fulfilment of the requirements for the degree of MSc in CEH
For Academic Year 2008-2009
Acknowledgement:
I would like to say thank you so much to my supervisor Dr Anthony Solomon for his
immeasurable support and advise he has been giving to me starting from the first day I met
him. This project work would have not been completed without his continued assistance and
support.
I would like to extend my thanks and deep appreciation for Dr Daksha Patel, our course
director and clinical lecturer, for her support at different times in the course of this project
work.
I am very thankful for ORBIS UK for sponsoring me to study this MSc in Community Eye
Health course at the renowned LSHTM and also funding the summer project work and the
forthcoming alumni workshop.
My thanks and gratitude also extend to JJ/WBGSP (Joint Japan/World Bank Graduate Study
Program) who co-sponsored me to study this masters course at LSHTM, University of
London.
I would like to thank the School Trust Fund for covering the cost of round trip flight ticket to
Ethiopia for this project work.
I am also very grateful to all participants of the research and those who supported me in the
study in Sekoru district, Jimma zone, Ethiopia.
Finally, I would like to thank all the staffs at ICEH (International Centre for Eye Health) and
lecturers from other Universities who delivered and thought us these state-of-the-art lectures
in community eye health without reservations.
2
Contents:
Page
Acknowledgements ………………………………….…....……...………………......…2
Table of contents………………………………………..…………..…...…….…..…….3
Abbreviations....................................................................................................…...5
List of tables and figures……………………………………..……...…….….…...…….6
Abstract ……………………………………………………………........…....….…..…...7
1. Introduction ………………………………………………………......…....……..…...8
1.1 Background………………………………………………………............…..……..8
1.2 Literature review……………………………………………….…….............……..8
1.2.1
Definitions……………………………………………………................……8
1.2.2
Magnitude of visual impairment worldwide………………................……9
1.2.3
Magnitude and causes of blindness worldwide…………...............…….10
1.2.4
Epidemiology of childhood blindness……………………..........……....…11
1.2.4.1
Childhood blindness worldwide………………………............….......…..11
1.2.4.2
Childhood blindness in Africa ……………………….................…....…..12
1.2.4.3
Ethiopia.................................................................................................13
1.3
1.2.4.3.1
Country profile.............................................................................13
1.2.4.3.2
Health coverage..........................................................................13
1.2.4.3.3
Eye care in Ethiopia....................................................................14
1.2.4.3.4
Magnitude of visual impairment in Ethiopia.................................14
1.2.4.3.5
Childhood blindness in Ethiopia..................................................15
1.2.4.3.6
VISION 2020 and Ethiopia..........................................................16
1.2.4.3.7
Partners in eye care in Ethiopia......………………....……..…......16
Rationale …………………………………………………….......…..….……...….17
2.
Aim and objectives of the study…………………………………...…....………......18
3.
Methodology………………………………………………………......…………...…19
3.1
Study design, subjects and study area………………………….....…….……...19
3.2
Ethical approval………………………………………………….........….….….…19
3.3
Sample size calculation...............................................................................….20
3.4
Selection criteria………………………………………………….........…..…..…..20
3.5
Selection of key informants………………………………………........…...….…20
3.6
Training of key informants................................................................................21
3.7
Data collection……………………………………………………................….…..22
3.8
Examination of identified children by Key Informants.......................................22
3.9
Data entry and analysis………………………………………….........…...…..…..24
3
page
4. Results……………………………………………………….………....….….……. 25
5. Discussions…………………………………………………………....…....……….30
6. Conclusions………………………………………………………….......….….……36
7. Recommendation……………………………………………………......…....……..37
8. References.........................................................................................................38
9. Appendices ………………......………………………………………...............……41
4
Abbreviations:
AMD
-Age-related Macular Degeneration
CBM
-Christian Blind Mission
CHA
-Community Health Agents
CBRHA
-Community Based Reproductive Health Agents
EPI
-Expanded Program of Immunization
IAPB
-International Agency for the Prevention of Blindness
ICD-10
-International Statistical Classification of Diseases and Related Health
Problems, 10th revision
IMR
-Infant Mortality Rate
KI
-Key Informant
KIM
-Key Informant Method
logMAR
-Logarithm of Minimum Angle of Resolution
LP
-Light Perception
LSHTM
-London School of Hygiene & Tropical Medicine
NCPB
-National Committee for the Prevention of Blindness
NLP
-No Light Perception
ORBIS
-ORBIS International, Inc.
PA
-Peasant Association
RE
-Refractive Error
SVI
-Severe Visual Impairment
U5MR
-Under Five Mortality Rate
UNICEF
-United Nations Children’s Fund
VA
-Visual Acuity
VAD
-Vitamin A Deficiency
VI
-Visual Impairment
WHO
-World Health Organisation
WHO/PBL
-WHO Prevention of Blindness
5
List of tables and figures:
Tables:
Table 1.
Category of blindness and low vision (visual impairment)
Table 2.
Magnitude of visual impairment worldwide, 2004
Table 3.
Association between level of income and prevalence of childhood blindness.
Table 4.
Summary of field activities at Sekoru district.
Table 5.
Key informants trained and number of blind/SVI children identified
Table 6.
Age & sex characteristics of blind/SVI children identified
Table 7.
Anatomical causes of blindness/SVI
Table 8.
Proportion of identified children who were blind and SVI.
Table 9.
Causes of blindness/SVI by age group.
Table 10.
Aetiological classification of causes of blindness/SVI.
Figures:
Figure 1.
Magnitude and Causes of blindness globally, 2004.
Figure 2.
Map of Ethiopia
Figure 3.
Causes of visual impairment (blindness and low vision) in Ethiopia.
Figure 4.
Map of the study area (Sekoru district):
Figure 5.
Flow diagram of children identified by KIs as blind/SVI.
Figure 6.
Aetiological classification of causes of childhood blindness/SVI at Sekoru
district.
Figure 7.
Proportion of avoidable/unavoidable causes of blindness/SVI and
reversible/irreversible vision loss at Sekoru district, Ethiopia
6
Abstract:
Background/Aim: Most studies on childhood blindness in sub-Saharan African countries
have been performed in schools for the blind. As in many countries, there are no populationbased data on childhood blindness in Ethiopia.
The overall aim of this study was to
determine the magnitude and causes of childhood blindness/severe visual impairment (SVI)
using the key informant (KI) method in Sekoru district, Jimma zone, Ethiopia.
Methodology: A population-based cross-sectional survey was performed in Sekoru district,
Jimma zone, Ethiopia in June and July 2009. We selected 42 KIs and trained them to
identify blind/SVI children aged <16 years. Identified children were examined by the
candidate, an ophthalmologist. Causes of blindness/SVI were identified and the prevalence
of childhood blindness was estimated.
Results: The KIs identified 112 children of whom 36 (32%) were blind/SVI. Twenty (56%)
were male and 16 (44%) female. Mean age was 10.7 years. The district prevalence of
childhood blindness/SVI was 0.062% (95% CI 0.042-0.082). The anatomical causes of
blindness/SVI were lens-related in 33% (12 cases), cornea in 28% (10 cases), whole globe
[glaucoma in 11% (4 cases) and phthisis bulbi in 8% (3 cases)], refractive error in 17% (6
cases) and optic nerve in 3% (1 case). Avoidable causes of blindness accounted for 89% of
cases.
Conclusion: The majority of childhood blindness/SVI in Sekoru district is avoidable. Lensrelated abnormalities (mainly congenital cataract) were the commonest causes of childhood
blindness/SVI in Sekoru district. A paediatric ophthalmic surgical set-up is required in the
region.
Key words: Childhood blindness, Ethiopia, key informant, Sekoru district, visual impairment.
7
1. Introduction:
1.1 Background:
According to the new global estimates by the World Health Organization (WHO), there are
approximately 314 million people around the world whose vision is impaired, due either to
eye diseases or uncorrected refractive errors. Of this number, forty-five million are blind
(about thirty-seven million from eye diseases and eight million from uncorrected refractive
errors). Ninety percent of these blind people live in developing world where blindness
remains one of the major public health problems. Women are at higher risk of blindness than
men and they constitute at least sixty percent of the blindness worldwide.1-3
Globally, up to seventy-five percent of all blindness in adults is avoidable (either preventable
or treatable). In developing countries this number could be as high as ninety percent. The
causes of blindness worldwide are variable and differ from one continent to another and
between countries depending on access to and availability of health facilities and
socioeconomic status. But generally common causes of blindness include cataract,
uncorrected refractive errors, glaucoma, age-related macular degeneration, and corneal
opacity (mainly from trachoma and onchocerciasis).1
Childhood blindness is one of the five ocular conditions established as immediate priorities
for control by the collaboration between the International Agency for the Prevention of
Blindness (IAPB) and WHO that is known as VISION 2020: The Right to Sight. VISION
20202 is the global initiative for the elimination of avoidable blindness by the year 2020.
Unlike in adults, only about fifty percent of all childhood blindness is avoidable.4 The major
preventable causes include vitamin A deficiency, measles, trachoma, harmful traditional eye
medicines and ophthalmia neonatorum. Cataract, glaucoma and retinopathy of prematurity
are common surgically treatable causes of childhood blindness. The VISION 2020 initiative
aims to reduce the prevalence of blindness in children from the present 0.75 per 1000
children to 0.40 per 1000 children by the year 2020.5
1.2 Literature Review:
1.2.1
Definitions:
According to the UNICEF definition, a child is defined as an individual whose age is less
than 16 years.
According to WHO, blindness is defined as best corrected vision of less than 3/60 in the
better eye or a visual field no greater than 10° in radius around central fixation.6
Low vision is defined as visual acuity of less than 6/18 but equal to or better than 3/60 or a
corresponding visual field loss to less than 200 in the better eye with best possible correction.
8
Visual impairment (VI) includes both blindness and low vision.
Severe visual impairment (SVI) is defined as best corrected visual acuity worse than 6/60
but better or equal to 3/60 in the better eye.
Based on recommendations from WHO study group on the prevention of blindness, 7 visual
impairment has been divided into six strata by the International Statistical Classification of
Diseases and Related Health Problems, 10th revision (ICD-10).8 (See table 1)
Table 1. Category of blindness and low vision (visual impairment)7
Visual acuity with best possible correction
Category of
Maximum less than:
Minimum equal to or better than
1
6/18
6/60
2
6/60
3/60
3
3/60
1/60
4
1/60
Light perception (LP)
Blindness
Low
vision
VI
5
No light perception (NLP)
9
Undetermined or unspecified
1.2.2 Magnitude of visual impairment worldwide
The new global estimate of visual impairment (reported in a 2006 WHO press release) was
based on presenting vision rather than best corrected vision.1, 2 According to the revised
ICD-10 categories and definition of VI formulated in Geneva in 2003, blindness is defined as
presenting vision of less than 3/60 or a visual field of the better eye no greater than 10° in
radius around central fixation.9 Based on this definition there are 314 million people with VI
globally.2 The new definition has helped considerably in estimating the extent of VI resulting
from uncorrected refractive errors (table 2).
9
Table 2. Magnitude of visual impairment worldwide, 2004*
Number in millions
Category of VI
RE (uncorrected)
All other causes
Total
Low vision
145
124
269 (85.7%)
Blindness
8
37
45 (14.3%)
153 (48.7%)
161 (51.3%)
314 (100%)
Total
*Adapted from Resnikoff 2008
1
In 2002 estimates, the number of visual impairment people was put at 161 million. The
newer estimates nearly double this with the addition of 153 million cases of uncorrected RE
of whom 8 million are thought to be blind. The new estimate also shows that RE is the
commonest cause of visual impairment and the second commonest cause of blindness
globally.1, 2
1.2.3 Magnitude and Causes of blindness worldwide:
Globally there are 45 million people who are blind. Cataract is the commonest cause of
blindness accounting for 39.1% of cases, followed by uncorrected RE at 18.2% and
glaucoma 10.1%. Ninety percent of blind people in the world live in developing countries. 1, 10
Childhood blindness accounts for 3.2% of the burden of blindness worldwide which means
there are about 1.44 million blind children (figure 1).
Cataract
39.1
RE
18.2
Glaucoma
10.1
AMD
7.1
Corneal opacities
4.2
DR
3.9
Childhood blindness
3.2
Trachoma
2.9
Onchocerciasis
0.7
Others
10.6
0
5
10
15
20
25
30
35
Percent
Figure 1. Magnitude and Causes of blindness globally, 2004.
10
40
45
1.2.4 Epidemiology of childhood blindness:
1.2.4.1 -Childhood Blindness worldwide:
It is estimated that there are about 1.4 million blind children in the world and the prevalence
of childhood blindness ranges from 0.3/1000 children age less than 16 years in the
wealthiest countries up to 1.5/1000 children in very poor countries. This makes the overall
prevalence of childhood blindness 0.75 per one thousand children.10, 11
Worldwide, about half a million children become blind each year, nearly one per minute.
Most of this blindness occurs in children living in the sub Saharan and Asian countries. Many
of these children die in their childhood from the underlying causes of blindness such as
measles, VAD, meningitis, rubella, prematurity, genetic diseases and head injuries.10, 12
Childhood blindness accounts for only 3.2 percent of the burden of global blindness. 1,
13
Compared to the total number of people who are blind worldwide which is about 45 million,
the number of blind children in the world seems small. Nevertheless, childhood blindness is
one of the initial five priority areas of the IAPB/WHO VISION 2020, the Right to Sight
initiative, a global campaign for the elimination of avoidable blindness by the year 2020.10
A number of reasons can be offered for prioritising blindness in childhood despite its
relatively small contribution to the overall global prevalence. First, assuming they survive,
blind children have many more years of blindness ahead of them than do blind adults, with
an estimated 75 million blind-years (number blind x length of life) in total.12 Second, as
already indicated, many of the causes of blindness in children are associated with deaths in
childhood. Over 50% of children who are blind in developing countries die within 1-2 years of
becoming blind.14, 15 Third, the causes of blindness in children differ from those in adults; as
a result different strategies and control measures are needed. Fourth, blindness in children
has to be treated as soon as diagnosis is made because irreversible loss of vision may occur
from amblyopia if this is not done : this is not the case in blindness that commences in adult
life. Failure of normal visual maturation during childhood cannot be corrected in adult life,
thus there is an element of urgency in treating blindness in children. Fifth, about 50% of
causes of blindness in children are as a result of avoidable causes mainly cataract and VAD
which can be either treated or prevented with proper eye care services.4
Causes of childhood blindness:
There are two ways of classifying the causes of blindness in children: anatomical and
aetiological. The anatomical way of classification depends on the most affected part of the
eye and is useful as information can be collected on all children. The aetiological
11
classification on the other hand is useful for planning preventive measures in large scale in a
population but obtaining reliable data is more difficult.10
Causes of blindness in children vary from region to region depending on the socioeconomic
development of countries. In the poor countries of Africa and Asia corneal scarring (mainly
from VAD), cataract and glaucoma are the major causes of childhood blindness. But in
affluent countries genetic eye diseases, ocular anomalies and CNS lesions are the
predominant causes of childhood blindness.15
1.2.4.2 -Childhood blindness in Africa:
The poorest regions of Africa and Asia are where three quarters of the world's blind children
live.14 Out of the 1.4 million blind children globally, about 300,000 live in Africa.12 The
prevalence of blindness in children in a country is related to the nutritional, health and
socioeconomic status of that country and hence the under 5 mortality rate (U5MR). It is
estimated that countries with U5MR in excess of 170/1000 have a prevalence of childhood
blindness in excess of 0.1%, while those with U5MR below 30/1000 probably have a
prevalence of 0.02-0.05% children.4, 16-19
Prevalence of blindness can also be estimated depending on the socioeconomic status and
level of development of countries. Those very poor countries have the highest prevalence of
childhood blindness while affluent countries have the lowest prevalence (table 3).20
Table 3. Association between country’s level of income and development and
prevalence of childhood blindness.20
Level of income
Very low
Low
Middle
High
Prevalence of childhood blindness
per 1000 children
1.2
0.9
0.6
0.3
The difference in prevalence of childhood blindness between the richest and the poorest
countries of the world may be as high as ten-folds (0.1/1000 versus 1.1/1000).21
Besides lack of adequate data on the extent of childhood blindness in African countries,
most studies that have been performed have not been community-based but generally
performed solely or principally within schools for the blind. These studies therefore may not
reflect the true causes and magnitude of childhood blindness in the region as they are prone
to different systematic error. Short of that, these studies have until now been the most useful
means of estimating magnitude and causes of childhood blindness. According to studies
12
made at different countries in schools for the blind, majority of blindness in children in Africa
are due to avoidable causes.22-24
1.2.4.3 - Ethiopia:
1.2.4.3.1 Country profile:
Ethiopia is a developing country located in the Eastern Africa. It is a highland complex of
mountains and plateaus divided by the Great Rift Valley. It is a land-locked country with a
total surface area of 1,127,127 km². It is bordered by Sudan to the West, Kenya to the South,
Somalia to the East, Eritrea to the North and Djibouti to the Northeast. It has three climatic
zones: the cool zone, the temperate zone and the hot zone. Ethiopia has a population of
73.9 million people with various cultural, religious and ethnicity origins. Eighty five percent of
its population live in rural areas and 45% of the population is consisting of children under the
age of 15 years. It has an adult literacy rate of 41.5%.25, 26
Figure 2. Map of Ethiopia
1.2.4.3.2 Health coverage:
Health care services in Ethiopia are very limited and generally of poor quality. Health
coverage is estimated to be only about 43% according to a report in the year 2005. 27
Utilization of the available health services is also low, hospital admission rate is 1.5%,
antenatal care follow up is 32%, attended delivery is only 12%, measles immunisation
coverage ranges from 54.3% to 65%, under-five mortality rate (U5MR) is 119 per 1000
children and infant mortality rate (IMR) is 75 per 1000 live births.27-29
13
1.2.4.3.3 Eye care in Ethiopia:
As is true in most sub-Saharan African countries there is no adequate eye care service
delivery system in Ethiopia. Many reasons can be given for this. The country lacks sufficient
number of skilled eye care professionals at all levels of hierarchy and service delivery. The
number of eye care professionals is very limited and inadequate for the large population of
Ethiopia. To make things worse the available eye care professionals are unevenly distributed
in the country being concentrated in the main cities. For example of the 100
ophthalmologists in the country, 60% (60) live and work in the capital city Addis Ababa
serving only the 2.7 million inhabitants of the capital city. This leaves the 71 million people
living out of Addis Ababa (where majority of the blind is also residing) to be served by only
40 ophthalmologists. The proportion of ophthalmologists to population ratio is therefore
about 1 to 1.8 million in rural areas and 1 to 45,000 in the capital. Of the 100
ophthalmologists in the country six have been trained in community eye health, another six
have been trained in cornea and external eye diseases, four are paediatric ophthalmologists,
three are glaucoma specialists, four are retina specialists and one has training in
oculoplastics. The rest are general ophthalmologists.
In comparison to the country’s population, the number of eye care personnel is so small as
there are few training centres for eye care professionals in the country. Until recently there
was only one training centre for ophthalmologists (Addis Ababa University) which graduates
only 4 to 5 ophthalmologists each year. For the last 3 years Jimma University has started
training ophthalmologists as well as cataract surgeons. Recently there has been some
progress in this regard, in that training centres for cataract surgeons, ophthalmic officers,
optometrists and ophthalmic nurses are opening in different areas in the country.
The cataract surgical rate for Ethiopia is only 357 per million population per year, far behind
WHO recommendations for the region.30
1.2.4.3.4 Magnitude of visual impairment in Ethiopia:
Ethiopia has one of the highest prevalences of blindness in the world. The national blindness
survey which was conducted in 2006 revealed that the prevalence of blindness in the
country was 1.6%.31 There are about 1.2 million blind people in the country which means
that Ethiopia alone contributes for 2.7% of the total blindness worldwide. The prevalence of
low vision (presenting vision less than 6/18 but equal to or better than 3/60 in the better eye)
is also high at 3.7%.
The causes of blindness are as follows: cataract accounts for 49.9% of the blindness
followed by corneal opacity (mainly trachomatous) 19.3%, refractive error 7.8%, glaucoma
5.2%, and macular degeneration 4.8%. The three commonest causes of low vision as shown
14
in figure 3 below are cataract accounting for 42.3%, refractive error 33.4% and corneal
opacity 13.6%.
%
49.9
50
45
42.3
40
33.4
35
30
25
20
15
10
19.3
13.6
Blindness
13
7.8
5.2
5
4.8 4.6
6.1
Low vision
0
0
Figure 3. Causes of visual impairment (blindness and low vision) in Ethiopia.31
Respectively, about 87.4% and 91.2% of the causes of blindness and low vision in Ethiopia
are avoidable (either preventable or treatable).
1.2.4.3.5 Childhood blindness in Ethiopia:
The national blindness survey done in 2006 showed a very high prevalence of childhood
blindness which is 0.1%. This accounts for over 6% of the total blindness burden in
Ethiopia.31 Taking the current population of the country there are about 33,000 blind children
in Ethiopia. Despite this huge number of blind children in the country, there is only one
paediatric eye care facility nationwide, which is located in the capital city. As already
mentioned, there are only four paediatric ophthalmologists in the country and therefore most
eye problems in children are handled by either the general ophthalmologist or other health
care professionals in a set up where appropriate diagnostic and therapeutic facilities are
lacking. According to a study performed in three blind schools in Ethiopia the three common
anatomical sites of blindness in 295 children less than 16 years of age were cornea (62.4%),
optic nerve (9.8%) and lens (9.2%).22
15
The national blindness survey revealed that the prevalence of trachomatous trichiasis
(blinding trachoma) in children of age group 1 to 9 years was 3.1% and the national
prevalence of active trachoma in this age group was 40.14%.32 Another community-based
study in central Ethiopia showed that 51.1% of children less than 10 years of age had active
trachoma
(trachomatous
inflammation-follicular
and/or
trachomatous
inflammation-
intense).33
Significant proportions of children are also blind due to corneal scarring resulting from
vitamin A deficiency. The national blindness survey showed that in those less than five years
of age the prevalences of night blindness, conjunctival xerosis and Bitot’s spots were 0.1%,
0.9% and 0.7% respectively.31
1.2.4.3.6 VISION 2020 and Ethiopia
Ethiopia was one of the first sub-Saharan countries to sign the declaration of support for the
global initiative VISION 2020: The Right to Sight. The initiative was launched in Ethiopia in
September 2002.34
Ethiopia has established a VISION 2020 National Committee for the Prevention of Blindness
(NCPB). It has developed and implemented the first phase national five-year strategic plan
for eye care (2001-2005) and also the second phase strategic plan (2006-2010) with active
participation of regional states of the country and all partners involved in the prevention of
blindness.34
Even if the country has a shortage of resources (skilled professionals and budget) with
regard to eye care services, it is trying hard to fulfil and implement successfully the VISION
2020 initiative. Some progress has been made in the country especially with regard to
infrastructure and human resource development in eye care. New training centres for
ophthalmologists, optometrists, ophthalmic officers, cataract surgeons and ophthalmic
nurses have been opened in several locations, and the number of trainees enrolled for
training at these institutions has increased.
The other big achievement was the completion of the National Survey on Blindness, Low
Vision and Trachoma in Ethiopia in 2006. The country is now in the second phase of the
five-year national strategic plan (2006-2010) for prevention and control of blindness within
the VISION 2020 program.
1.2.4.3.7 Partners in eye care in Ethiopia:
In addition to the federal ministry of health, there are a number of nongovernmental
organizations and civic societies which are directly involved in prevention of blindness in
Ethiopia. These organizations include the following: ORBIS International, Christian Blind
Mission (CBM), Light for the World, International Trachoma Initiative (ITI), Help Age
16
International, Menschen fur Menschen (MFM), The Carter Centre, Girarbet Rehabilitation
Project, World Vision, Lions Club, and Rotary Club. Had it not been for the great support
from these non-profit making organizations, the progresses seen in eye care service delivery
and human resource developments in Ethiopia would have not been achieved.
The role they play and the work they perform is magnificent and to mention some: they are
involved in human resource development by training eye care professionals abroad and
within the country and bringing skilled and experienced expatriates to give free services.
They are also involved in building infrastructures, eye care training centres and furnishing
and equipping them, strengthening the available eye health facilities both in material
supplies and human resources.
1.3 -Rationale:
The causes of childhood blindness in Ethiopia are not well established and up to this time
period there is no separate childhood blindness survey done at a community level in the
country to identify the real causes, magnitude and risk factors for childhood blindness. Data
available concerning childhood blindness in the country were obtained from either studies at
schools for the blind, hospital records or from national blindness surveys where more
emphasis had been given to adulthood blindness. Therefore it has been difficult to plan and
implement control and preventive measures to tackle childhood blindness in the country as
more realistic and evidence-based data regarding the magnitude and extent of the problem
have been lacking.
This study will identify the causes and magnitude of childhood blindness at a community
level in Sekoru district using the key informant method (KIM) which is a relatively new but
effective method to identify children with blindness or severe visual impairment through a
house-to-house searching strategy.35-40 The findings of this study will help to plan ways to
control blindness in children in Ethiopia.
17
2. Aim and objectives of the study:
Aim:
The overall aim of the study was to determine the magnitude and causes of childhood
blindness and severe visual impairment in Sekoru district, Jimma zone, South West Ethiopia.
Objectives:
The specific objectives were:
1- to estimate the prevalence of childhood blindness using the key informant method,
2- to identify the causes and estimate the relative contribution of each cause to the
overall prevalence of childhood blindness,
3- to estimate the proportion of blind children who lost vision from avoidable causes of
blindness,
4- to propose ways of preventing and controlling childhood blindness in the district, and
5- to train suitable key informants to find children with blindness or SVI in the district.
18
3. Methodology
3.1 Study design, subjects and area
Study design: a population-based cross sectional survey.
Study population: children less than 16 years of age living in Sekoru district of Jimma zone.
Study subjects: blind/SVI children less than 16 years of age living in Sekoru district.
Study period: from June 2009 to September 2009.
Study area: Sekoru district of Jimma zone.
Jimma zone is about 325km South West of the capital and has 13 districts. It has a total
population of about 2.5 million. Sekoru district has 136,297 inhabitants and is about 100kms
far Northeast from Jimma town.25 Among others this district was selected for the study
because June and July are monsoon seasons in Ethiopia where there is heavy and torrential
rainfall and compared to the other districts with regard to transportations, access to Sekoru
district during this season is relatively better.
N
Main road
Limu seka
Distribution
of
villages
Limu
u
Kosa
Jimma zone
Sekoru district
Figure 4. Map of the study area (Sekoru district):
3.2 Ethical approval:
Ethical approval for the study was obtained from the ethics committee of the London School
of Hygiene & Tropical Medicine (LSHTM) and the Research and Publication Committee of
19
Jimma University Hospital. Consent forms were signed by parents or guardians of blind/SVI
children in the presence of witnesses before children were recruited for the study.
3.3 Sample size calculation:
The expected prevalence of childhood blindness was 0.1%. For a population of 58,480
children in Sekoru district, worst acceptable result of 0.08% and confidence level of 95%, the
sample size calculated using Epi info was 36,333. For 99% confidence level, it became
43,225.
3.4 Selection criteria:
Inclusion criteria:
All children less than 16 years of age with presenting vision less than 6/60 in the better eye
(i.e. blind or SVI according to WHO revised ICD-10 categories of VI9) and living in Sekoru
district of Jimma zone were eligible for inclusion.
Exclusion criteria:

children not meeting the inclusion criteria (specifically children whose presenting
vision was ≥6/60 in either eye,

Children unable to come to the examination centres for any reason,

Children for whom consent to participate was withheld.
3.5 Selection of key informants:
To be eligible for selection as a KI, candidates were required to satisfy all of the following
criteria:

Permanent residence in Sekoru district

Ability to read and write

Ability to speak the local language perfectly

Age not greater than 60 years
Selection procedure
Following explanation about the objectives of the study and thorough discussion with the
head and vice head of Sekoru district health bureau, three community mobilizers (who also
acted as supervisors for the KIs) were selected for the study. Then, discussion was made on
who could be the best KIs in the district. Agreement was reached on selecting those people
who had been working as Community Based Reproductive Health Agents (CBRHA) in the
district. The CBRHAs were inhabitants in the community who had had frequent previous
trainings about common health problems in their community particularly malaria and
tuberculosis. They were also involved in the expanded program for immunization (EPI), polio
20
vaccination and vitamin A distributions. They had in-depth knowledge of the customs and
culture of their communities, spoke the local language fluently and were educated (at least
able to read and write).
There were 34 peasant associations (PA) and four towns in Sekoru district. For each PA, we
selected one KI, and for each town two KIs, making a total of 42 KIs. The supervisors
contacted all the selected KIs to see if they were willing to participate in the study, and all
agreed to do the job.
3.6 Training the Key Informants
Training sites
Training of the KIs was performed on two separate days in two groups at two towns. The
training was performed at Sekoru High School in Sekoru town for the first group and at
Kumbi High School in Kumbi town for the second group. The first group consisting of 23 KIs
was trained on 25/06/09 and the second group of 19 KIs was trained on 26/06/09.
Training procedure
The purpose of the study was explained to the KIs. Basic information about childhood
blindness globally, its magnitude and common causes and the importance of identifying and
treating childhood blindness early were discussed in detail. Pictures of children who had
been blinded or severely visually impaired as a result of common eye diseases were shown.
Discussions were held with the KIs about how to find blind/SVI children living in the towns,
villages and PAs.
The KIs were also trained on how to measure visual acuity (VA) at 6 metres using the Eletter, including demonstrations on subjects. The KIs then practiced measuring VA on each
other until they were all performing this task well. Lots of questions were raised by the KIs
including whether or not to bring children with eye problems or eye discharge who were still
able to identify the E-letter at six metres, children who were blind in one eye only, or children
who could see at day time but not at dusk or night hours, etc. These questions were
answered by the main investigator. The training was given for half a day at the selected sites
for each group on two different days.
Finally, six convenient examination sites (one health centre and five clinics) were chosen for
later examination of identified blind/SVI children by the ophthalmologist could take place.
Each KI was given instructions on where and on which days they should take the blind/SVI
children they identified. The examination centres chosen were Sekoru health centre, Baso
clinic, Deneba clinic, Natri clinic, Kumbi clinic and Abelti clinic. Each KI was given an E-letter,
a pen and a notepad.
21
3.7 Data collection
Finding blind/SVI children:
Following the half day training, each KI returned to their respective village and contacted the
village leaders. The KI together with the village leader explained their new task and duty to
the villagers in places where people gather like religious areas, market places and
community meetings. The community were asked to name or bring those children with visual
impairment to the KI. The village leader also identified for the KI all village households with
children who the village leader knew to have eye problems. The KI also contacted the
church and mosque leaders who introduced him/her and asked the people to bring all
children with vision problem to the KI. The KIs also announced to the public at market
places and sensitized the community.
The main job of the KI was to go systematically from house to house through all the villages
for which they have been assigned responsibility, and look for children with visual problems.
For identified children > 5 years of age considered to be blind/SVI, vision was measured by
the KI outdoors and in daylight at six metres using the E letter. All children <5 years of age
and suspected of being blind/SVI either by parents or KIs were brought to the examination
centres to be examined by the ophthalmologist.
The names, sex and ages of all children identified as blind/SVI by the KIs were listed.
Parents and guardians of children identified as blind/SVI by the KIs were told to bring the
child on the specified dates to one of the places identified above, for examination by the
ophthalmologist.
3.8 Examination of identified children by Key Informants
Consent form:
The KIs came to the examination centres together with the identified blind/SVI children and
their parents/guardian. Before the ophthalmologist examined children brought by the KIs at
the chosen referral places, the purpose of the study was explained to each parent, their
willingness to participate was confirmed and the consent was read aloud to them in the local
language before being signed by each parent. Only then did the investigator proceed to
examine the children.
Measuring visual acuity:
Using a logarithm of minimum angle of resolution (logMAR) visual acuity chart, presenting
vision was measured at six metres in a well lit room for those above 5 years of age. Pinhole
vision was also measured and subjective refraction using a trial frame lens set was
performed for those whose vision showed improvement with pinhole. Neither intraocular
pressure nor visual field was assessed.
22
Ocular examination:
Ocular alignment and motility tests were performed. A torch and magnifying loop (+2.5) were
used to examine the adnexiae and anterior segment of the eye including the lens. Fundus
examination was performed using a direct ophthalmoscope. Cyclopentolate eye drops were
used to dilate the pupils when indicated. The most likely cause of blindness was identified
and finally diagnosis was made. Ocular findings of those diagnosed as blind/SVI were
recorded on the modified WHO/PBL eye examination record for children with blindness and
low vision.
For children with reversible causes of blindness referral to Jimma University Hospital was
made for proper management free of charge. Transportation fees were provided to parents
who said that they had no money for transport to Jimma Hospital. Parents of those with
irreversible causes of blindness were counselled and advised of the advantages of enrolling
their children in schools for the blind. Vitamin A capsules were distributed to all examined
children and full prescriptions were given to those who needed medications.
Figure 5. Flow diagram of children identified by KIs as blind/SVI.
Children with vision < 6/60 (better eye)
Referred to ophthalmologist (examination centres)
VA measured by ophthalmologist
VA > 6/60 (either eye)
VA <6/60 (better eye)
Excluded from the study
(Sent home with advise &/or
Treatment)
Recruited to the study
Consent form signed
History taking and Systematic ocular
examination done
Data recorded on WHO/PBL record form
Diagnosis & Management plan
(Counselling/Referral to eye hospital)
23
3.9 Data recording, entry and analysis:
At the examination centres, data obtained from examined blind/SVI children were recorded
on the WHO/PBL eye examination record for children with blindness and low vision form.41
Data cleansing/scrubbing was performed manually by the ophthalmologist. All data obtained
were entered manually into a computer on excel sheet and subsequently transferred to
SPSS and STATA softwares and analysed using SPSS 16 and STATA 10.1 software
programs (licensed to LSHTM student labs).
Table 4. Summary of field activities at Sekoru district.
Activities
Week 1
Week 2
Visiting the
area, KIs
selection &
training
Finding BL/SVI
children by KIs
Examination by
ophthalmologist
Networking
Monitoring
24
Week 3
Week 4
4. Results:
There were 42 KIs trained (one KI for each PA and two KIs for each town). Thirty-four (81%)
of them were males and 8 (19%) were females (table 5). Their ages ranged from 23 years to
54 years with a median and mean of 32 and 37 years respectively
Table 5. Key informants trained and number of blind/SVI children identified
KIs
NO. TRAINED (%)
NO. OF BLIND/SVI CHILDREN
IDENTIFIED (%)
34 (81)
31 (86)
8 (19)
5 (14)
42 (100)
36 (100)
Males
Females
TOTAL (%)
Children identified by KIs:
Hundred and twelve children were taken to the examination centres by the 39 KIs. Three KIs
(two males and one female) did not bring any children. This means on average one KI took 2
to 3 children to the examination centres. Of the 112 children examined 36 (32%) were either
blind or severely visually impaired. The rest had either minor visual problems or were
unilaterally blind.
There were 20 (55.5%) male and 16 (44.5%) female blind/SVI children identified making the
male to female ratio 1.25:1 (5:4). Seven (19.4%) of the blind/SVI children were below the
age of 6 years and 10 (27.8%) were between 6 and 11 years. Nineteen (52.8%) of the
identified blind/SVI children were above the age of ten. The mean age was 10.7 years.
Only six (16.7%) of the blind/SVI children were enrolled in schools, one in a school for the
blind near Addis Ababa, the rest (five) in integrated schools locally together with sighted
children. The age and sex distribution of the blind/SVI children is as follows.
Table 6. Age & sex characteristics of blind/SVI children identified
MALE
FEMALE
TOTAL (%)
0-5
4
3
7 (19.4)
6-10
6
4
10 (27.8)
11-15
10
9
19 (52.8)
TOTAL (%)
20 (55.5)
16 (44.5)
36 (100)
Age (years)
25
Causes of blindness/SVI:
The commonest anatomical site of pathology producing blindness/SVI was the lens which
accounted for 33.3% of the cases, followed by the cornea which was responsible for 27.8%
of cases. Of the seven children who had whole globe abnormalities four had congenital
glaucoma and three had bilateral phthisical eyes of unknown aetiology. Refractive error was
the next most common cause, accounting for 16.7% of blindness/SVI (table 7).
Table 7. Anatomical causes of blindness/SVI
ANATOMY
NUMBER
Whole globe
7
Cornea
10
Lens
12
Refractive error
6
Optic nerve
1
TOTAL
36
PERCENT
(95% CI)
19.4
(8.2-36.0)
27.8
(14.2-45.2)
33.3
(18.6-51.0)
16.7
(6.4-32.8)
2.8
(0.10-14.5)
100%
26
Pictures 1-4. Some of the children who were blind and identified by key informants
1.
A
child
with
congenital
2.
glaucoma and blind.
Bilateral
dense
cataract
in
a blind child (after pupils were
dilated).
4. Corneal scarring/phthisis in a 14-yr-old
3. Bilateral congenital cataract
girl secondary to VAD.
(before pupils were dilated).
27
Of the 36 children identified, 30 (83.3%) were blind, with presenting vision less than 3/60 and the rest 6
(16.7%) had SVI with presenting vision <6/60 but better or equal to 3/60 in the better eye (table 8).
Table 8. Proportion of identified children who were blind and SVI.
Visual acuity
Number
Percent
Blind
30
83.3
SVI
6
16.7
Total
36
100
Table 9. Causes of blindness/SVI by age group.
Causes
0-5 years
6-10 years
11-15 years
Cataract
3
3
6
Corneal opacity
3
2
5
Refractive error
0
3
3
Glaucoma
1
1
2
Phthisis bulbi
0
0
3
Optic hypoplasia
0
1
0
7 (19.4%)
10 (27.8%)
19 (52.8%)
Total
Total
(95% CI)
12 (33.3%)
(18.6-51.0)
10 (27.8%)
(14.2-45.2)
6 (16.7%)
(6.4-32.8)
4 (11.1%)
(3.1-26.1)
3 (8.3%)
(1.8-22.5)
1 (2.8%)
(0.1-14.5)
36 (100%)
In all age groups, cataract was the commonest cause of blindness. Corneal opacity and RE were
just as common as cataract as causes of blindness/SVI in age groups 0-5 and 6-10 years
respectively. Corneal opacity was the second commonest cause of blindness in age groups 11-15
years.
Most of the pathology seen in this cohort of blind/SVI children was of unknown aetiology, as seen in
the following table. In about 64% of cases (23 children) the underlying aetiology of blindness could
not be identified. The majority of these cases involved congenital cataract. In 25% (9 cases) of the
children factors acquired during childhood were the causes of blindness/SVI, these were mostly
corneal opacities resulted from VAD. Intrauterine factors accounted for 5.56% of the cases and
hereditary and neonatal factors accounted for 2.78% of the cases each.
28
Table 10. Aetiological classification of causes of blindness/SVI.
AETIOLOGY
NUMBER
Hereditary
1
Intrauterine
2
Neonatal
1
Postnatal
(infancy/childhood)
Unknown aetiology
9
23
TOTAL
36
PERCENT
(95% CI)
2.8
(0.1-14.5)
5.6
(0.7-18.7)
2.8
(0.1-14.5)
25
(12.1-42.2)
63.9
(46.2-79.2)
100%
Two of the children were operated on both eyes for congenital cataract previously (ECCE+PC-IOLExtra Capsular Cataract Extraction plus Posterior Chamber Intraocular Lens) but their vision
remained less than 6/60 due to bad outcomes. Another two were operated for congenital glaucoma
(partial thickness trabeculectomy was done).
29
5. Discussion:
The use of key informants is a relatively new method of identifying which children in a community
have visual problems. The key informant method (KIM) has been proven to be effective in
identifying blind/SVI children especially in low and very low income countries like Ethiopia where
resources to undertake more formal searches are scarce. KIs are relatively cheaper and also in
some countries they are volunteers who do not need any form of payments for their activity.35, 37, 38
In our study the key informants trained were people who have previously been serving their
community as Community Health Agents (CHA) previously and who had recently upskilled to
become Community Based Reproductive Health Agents (CBRHA). They had been working in this
post for four to eight years. They all had good knowledge and details of the community they were
working in and basic baseline information concerning health issues. They were able to cover their
respective PAs and villages within the time period allocated to find blind/SVI children. They brought
a total of 112 children to the examination centres from the 38 PAs and 4 towns in the district, of
whom 36 children (32%) were found to be either blind or SVI. This implies that of three children they
brought one was either blind or severely visually impaired.
Of the 136,000 people in Sekoru district about 43% (58,480) are children aged less than 16 years.
Based on the national blindness survey’s estimated childhood blindness prevalence of 0.1%, we
expected 58 blind children in Sekoru district. But we actually identified 36 blind/SVI children which
makes the prevalence of childhood blindness in Sekoru district 0.062% (95% CI =0.041-0.082) in
this study. This prevalence rate is lower than that of the national estimate which was undertaken in
2006 (0.062% vs. 0.1%).31
Thirty of the identified children (83.3%) in this study were blind having presenting vision of < 3/60 in
the better eye and the rest six (16.7%) had SVI (table 8). In a similar study undertaken in
Bangladesh, 91.5% of the 1935 identified children were blind and the rest (8.5%) were severely
visually impaired.36
Most of the blind children identified were in the higher age group. Nineteen (52.7%) of the blind/SVI
children were aged 11 to 15 years, of whom 8 were 15 years of age. This is similar to the
Bangladesh study where over half of the studied children were aged 11-15 years.36 It is of course
difficult to prove ages of the children as there is no official registration of births in these rural
communities, so we relied on parental report. Therefore some of those who claimed to be 15 years
of age might actually have been older than that. In this study the mean age was 10.4 years which is
higher than the mean age obtained in a similar study in Malawi (8.0 years).39
30
Causes of blindness and SVI:
According to site of abnormality:
Causes and prevalence of childhood blindness vary from country to country depending on the socio
economic status, U5MRs and availability of health care facilities. In affluent countries prevalence is
very low and most of the causes of blindness are due to factors which are unavoidable (not
preventable or treatable).14, 20 In very poor developing countries like Ethiopia the prevalence is very
high and the majority of the cases are due to avoidable conditions like cataract and corneal scarring
resulting from VAD.20
Lens abnormality (congenital cataract and pseudophakia) was the commonest anatomical cause of
blindness identified in this study. It accounted for 33.3% (12 cases) of all blindness. Of the 12 cases
identified ten had congenital cataract and two were pseudophakic who developed dense posterior
capsular opacity. Previous study in three schools for the blind in Ethiopia showed that
cataract/aphakia accounted only for 9.2% of blindness which is much lower than in this study. 22 In
other community based studies using KIs in Malawi39 and Bangladesh,36 lens abnormalities
accounted for 35% and 32.5% of blindness respectively: similar proportion to the current work.
Cataract is now replacing corneal scarring as the leading cause of childhood blindness and low
vision in sub Saharan African countries and the rest of the developing world. There is a reduction in
prevalence of preventable causes of childhood blindness in developing countries as a result of
better measles immunization coverage and distribution of vitamin A capsules to young children. 4, 20,
24, 36, 42
Corneal scarring due to vitamin A deficiency was the second commonest cause of vision loss in
children in this study accounting for 27.8% of all cases. In the previous study in schools for the blind
in Ethiopia carried out in 2001 VAD accounted for 62.4% of blindness.22 Even though direct
comparison may not be possible, this apparent reduction in prevalence of blindness from VAD could
be due partly to the extended distribution of vitamin A capsules to children during the expanded
programs of immunisation plus better measles immunization coverage and due to relatively better
health care services nowadays. The health care service delivery system and the number of health
posts in the rural areas is now relatively better than the previous periods addressing the health
issues of most of the rural communities.
In studies in other settings, VAD does appear to be becoming second to congenital cataract as the
main cause of childhood blindness in the developing world. 24, 39 A recent study performed in schools
for the blind in four east African countries showed that corneal scarring/phthisis bulbi was the
commonest cause of blindness/SVI accounted for 19% of the cases. 43 Another study in India
showed that 19% (ranging from 8 to 27% in different States) of 1318 blind/SVI children examined
had lost vision due to VAD.44
The actual number of cases of blindness resulting from VAD could be higher and the prevalence of
blindness/SVI due to VAD could easily be underestimated by virtue of the fact that the chance of
31
dying from associated protein energy malnutrition and other essential nutrients in these children is
very high. The contribution of VAD to childhood mortality is a well known fact.45
There were six children (16.7%) with significantly high degree of refractive error. All of them were
cases of high myopia (10-12 dioptres) and none of them were wearing corrective glasses as they
had never been seen by eye health professionals. It was less likely that they had developed deep
amblyopia as in all cases vision improved to 6/18 - 6/60 with corrective glasses. This means they
would have been out of the blindness/SVI category had it not been for the lack of corrective glasses.
RE is not a major cause of blindness in children but is one of the common causes of low vision.46
Globally around 12.8 million children between 5-15 years of age have visual impairment as a result
of uncorrected or inadequately corrected RE making the global prevalence of RE in children 0.96%.1
In a study in Nigeria, however, RE was the cause of loss of vision in about 59% of those children
between 5 and 15 years of age.47
Congenital glaucoma was the cause of blindness in about 11.1% (4 cases) of children identified in
this study. Two cases had had the problem since their first year of life, as evidenced by the
presence of buphthalmos plus suggestive family history. In a similar study in Bangladesh, glaucoma
was the cause of blindness/SVI in 4.3% of the identified children.36 In the study made in schools for
the blind in Ethiopia, glaucoma/buphthalmos accounted for only 1.7% of the blindness. 22 In other
studies in schools for the blind in Nigeria,24 Malawi, Kenya, and Uganda23 and China48 glaucoma
and buphthalmos were the causes of blindness and SVI in 9.3%, 3.7%, 6.5%, 3.4% and 9% of the
children respectively.
There were three children (8.3%) with phthisis bulbi of unknown aetiology and only one case (2.8%)
of bilateral optic nerve hypoplasia with nystagmus which implies that the pathology had been there
since early life. In similar study in Bangladesh optic nerve diseases were responsible for blindness
in 5.3% of the identified children.36 In schools for the blind in Malawi, Kenya and Uganda optic nerve
lesions were found in 5.1%, 10.4% and 13.3% of the blind/SVI children respectively.23
According to the aetiology of Blindness/SVI:
In this study the majority of cases of blindness and SVI had unknown aetiology; in 63.89% of cases
it was not possible to categorize the blindness/SVI to one of WHO’s four aetiological classifications;
these cases involved congenital cataract. In schools for the blind in Ethiopia, the aetiology of
blindness/SVI could not be determined in 45.1% of children.22 Of cases of known aetiology, 25% of
blindness/SVI was due to childhood factors which are secondary to vitamin A deficiency in this
study. Kello found that childhood factors (mainly VAD) accounted for 49.8% of the cases.22 In the
study by Muhit et al, 30.7% of cases were due to childhood factors resulting in corneal scarring
principally from vitamin A deficiency.36 There were two congenital cataract cases secondary to
congenital rubella infection suggested by the type of the cataract they developed and lack of history
32
of immunization of the mother prior to pregnancy. There was also one case of bilateral corneal
scarring secondary to ophthalmia neonatorum.
2.78%
5.56%
2.78%
Hereditary
Intrauterine
25%
Perinatal
Childhood
63.89%
Unknown
Figure 6. Aetiological classification of causes of childhood blindness/SVI at Sekoru district.
Avoidable causes:
Majority of cases of blindness (89%) in this study were due to avoidable causes (either preventable
or treatable) and the children were therefore blind needlessly (figure 5). Cataract, corneal opacity,
RE, and congenital glaucoma are all treatable surgically; corrective glasses can easily be provided,
and other conditions were preventable with appropriate measures directed to the community
including health education, antenatal care and immunizations. A study done in South East Nigeria
suggested that 74.5% of cases there were avoidable.24
Out of the 36 blind/SVI children identified, vision could improve in 20 (55.5%) of them if appropriate
therapeutic measures were taken. Fourteen (38.9%) of the cases needed surgical interventions (ten
needed cataract extraction, two needed YAG laser capsulotomy, and two needed optical iridectomy)
and six (16.7%) cases required corrective glasses. But in the remaining 16 (44.5%) cases, vision
could improve neither with treatment nor with provision of glasses (i.e. they had irreversible vision
loss) (figure 7).
33
89%
90%
80%
Avoidable causes
70%
55.50%
60%
Unavoidable causes
44.50%
50%
40%
Reversible vision loss
Irreversible vision loss
30%
11%
20%
10%
0%
Childhood blindness
Figure 7. Proportion of avoidable/unavoidable causes of blindness/SVI and
reversible/irreversible vision loss at Sekoru district, Ethiopia.
Limitations of the study:
1. There was a lack of adequate baseline data and information concerning low vision and
blindness in childhood in the region. As is true in most developing countries, there is no
national blindness registration system in Ethiopia.
2. Following their one day training session, pretesting (pilot testing) of KIs on children in order
to demonstrate understanding of study procedures was not done.
3. The data collection period was short for the survey as KIs needed to travel long distances to
remote rural areas by foot.
4. June and July are monsoon months in Ethiopia and it was difficult for the KIs to travel to the
very remote and rural areas; unfortunately, due to restrictions imposed by the UK academic
year, these months were the only ones in which data collection could be completed.
Identified blind/SVI children and their parents also had difficulties coming to examination
centres as the roads were muddy and there were no means of transport except foot.
5. Children between 11-16 years of age might have been over represented in this study as they
constituted 52.8% of the study subjects. Consequently, the ocular diseases diagnosed in this
age group might have been overestimated.
6. Children who were blind/SVI but sick or unable to come to the examination centre for any
reason were not included in the study resulting in underestimation of overall prevalence, and
perhaps a bias in the estimation of the relative contribution of various causes of blindness
and SVI.
34
Strengths of the study included:
1. This was a community based survey performed using KIs which have been proven to be an
effective method in other African and Asian countries with similar socioeconomic status.
2. KIM is a type of population-based study; hence identified children using this method were
more likely to be representative of the children’s community, than, for example, studies
performed in schools for blind children.
3. The study was sufficiently powered: the theoretical population of children covered by the
study (the number of children in the district, 58,480) was higher than the calculated sample
size (36,333).
35
6. Conclusions:
Despite the limitations mentioned above, the following conclusions and recommendations are made:
1. The prevalence of childhood blindness and SVI in Sekoru district of Jimma zone is lower
than that estimated by the national blindness survey done three years ago (0.062% v 0.1%).
2. The causes of blindness in children in Sekoru district included congenital cataract, corneal
scarring from VAD, RE, congenital glaucoma, phthisis bulbi and optic hypoplasia.
3. Cataract is the major cause of blindness and SVI in Sekoru district followed by corneal
scarring resulting from VAD.
4. Refractive error is responsible for a significant proportion of childhood blindness/SVI in
Sekoru district. The attention given to this problem is clearly inadequate despite the fact that
it can be corrected with simple refraction and distribution of corrective glasses without the
need for more sophisticated intervention.
5. Overall eighty-nine percent of blindness and severe visual impairment in children in Sekoru
district is from avoidable causes.
6. Different studies in different countries have shown that identifying blind/SVI children in the
community using KIM is useful and relatively cheap. This is particularly true in resource
scarce countries where sophisticated ways of doing surveys may be difficult and too costly to
contemplate.35, 37, 38 This study has shown that KIs could be a useful means of ascertaining
children who are blind/SVI in rural community of Ethiopia.
36
7. Recommendations:
1. Cataract has been found to be the leading cause of childhood blindness in Sekoru district of
Jimma zone. To handle this problem effectively, it is recommended to train a paediatric
ophthalmologist and one anaesthesiologist to perform better quality cataract surgery for
these blind children in the region.
2. It is mandatory to equip and furnish adequately the existing ophthalmology department in
Jimma zone with appropriate paediatric ophthalmic instruments including operating
microscopes and general anaesthesia machines.
3. Corneal scarring is the second major cause of blindness in children in Sekoru district.
Conditions predisposing children to VAD like diarrheal diseases and respiratory infections
should be addressed properly. Health education, measles immunization, antenatal care
follow-up and vitamin A distributions need to be strengthened further.
4. Refraction services in the region need to be reinforced. Regular school vision screening
programs which will have a paramount importance in identifying children with refractive
errors in schools have to be started.
5. KIM can be used in Ethiopia to explore the magnitude and causes of childhood blindness
and SVI at zonal or national level.
37
8. References:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
Resnikoff Serge, et al., Global magnitude of visual impairment caused by uncorrected
refractive errors in 2004. Bulletin of the world health organisation, 2008. 86: p. 63-70.
WHO press release. Sight test and glasses could dramatically improve the lives of 150 million
people with poor vision. Geneva. 2006. Accessed online on August 24, 2009.
http://www.who.int/mediacentre/news/releases/2006/pr55/en/index.html.
Allen Foster, Clare Gilbert, and G. Johnson, Changing patterns in global blindness: 19882008. Community Eye Health, 2008. 21(67): p. 37-39.
Clare Gilbert and M. Muhit, Twenty years of childhood blindness: what have we learnt?
Community Eye Health Journal, 2008. 21(67): p. 46-47.
Clare Gilbert and H. Awan, Blindness in children. British Medical Journal, 2003. 327: p. 760761.
Resnikoff Serge, et al., Global data on visual impairment in the year 2002. Bulletin of the
World Health Organization, 2004. 82: p. 844-851.
WHO, Study Group on the Prevention of Blindness. WHO Technical Report Series No.518.
World Health Organization, Geneva, 1973: p. 10-11.
International Statistical Classification of Diseases and related Health Problems, 10th revision.
Geneva: World Health Organization 1992: p. 456-57.
WHO, Consultation on Development of Standards for Characterization of Vision Loss and
Visual Functioning. Geneva, 2003. Accessed online on August 24/08/2009,
http://whqlibdoc.who.int/hq/2003/WHO_PBL_03.91.pdf.
WHO, Preventing blindness in children: report of WHO/IAPB scientific meeting. Hyderabad,
India,
13-17
April
1999.
accessed
online
on
20/08/2009,
http://whqlibdoc.who.int/hq/2000/WHO_PBL_00.77.pdf.
Clare Gilbert, H.A., Blindness in children. British Medical Journal, 2003. 327: p. 760-761.
WHO, VISION 2020, The Right to Sight: . Global initiative for the elimination of avoidable
blindness:
Action
plan
2006-2011,
Accessed
online
on
22/08/2009,
http://www.who.int/blindness/Vision2020%20-report.pdf.
WHO, VISION 2020, The Right to Sight. . Global initiative for the elimination of avoidable
blindness:
Action
plan
2006-2011,
Accessed
online
on
22/08/2009,
http://www.who.int/blindness/Vision2020%20-report.pdf.
Clare Gilbert and A. Foster, Childhood blindness in the context of VISION 2020-The Right to
Sight. Bulletin of the World Health Organization, 2001. 79: p. 227-232.
Clare Gilbert, Jugnoo S Rahi, and G.E. Quinn, Visual impairment and blindness in children.
In: Gordon J J, Darwin C M, Robert A W, Sheila K W, eds. The Epidemiology of Eye
Disease, Arnold, 2003 p. 261-286.
Gilbert, C., New Issues in Childhood Blindness. Community Eye Health Journal, 2001.
14(40): p. 53-56.
Rakhi Dandona and L. Dandona, Socioeconomic status and blindness. Br J Ophthalmol, 2001.
85: p. 1484-88.
Foster A, G.C., Epidemiology of childhood blindness. Eye, 1992. 6: p. 172-176.
Susan Lewallen, P.C., Blindness in Africa: present situation and future needs. British Journal
of Ophthalmology, 2001. 85: p. 897-903.
Gilbert, C., Changing challenges in the control of blindness in children. Eye, 2007. 21(10): p.
1338-43.
Gilbert CE, et al., Prevalence of visual impairment in children: a review of available data.
Ophthalmic Epidemiology, 1999 6(1): p. 73-82.
Kello, A.B. and C. Gilbert, Causes of severe visual impairment and blindness in children in
schools for the blind in Ethiopia. British Journal of Ophthalmology, 2003. 87(5): p. 526-30.
38
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
Gilbert, C.E., et al., Causes of childhood blindness in east Africa: results in 491 pupils
attending 17 schools for the blind in Malawi, Kenya and Uganda. Ophthalmic epidemiology,
1995. 2(2): p. 77-84.
Ezegwui, I.R., R.E. Umeh, and U.F. Ezepue, Causes of childhood blindness: results from
schools for the blind in south eastern Nigeria. British Journal of Ophthalmology, 2003. 87(1):
p. 20-3.
Central Statstical Agency of Ethiopia. 2007. http://www.csa.gov.et/, (accessed online on
20/08/2009).
WorldHealthOrganization, Country Health System Fact Sheet 2006 Ethiopia.
http://www.afro.who.int/home/countries/fact_sheets/ethiopia.pdf, 2006(accessed online on
22/08/2009).
Samuel G, et al., Human Resource Development for Health in Ethiopia: Challenges of
Achieving the Millennium development Goals. Ethiopian Journal of Health Development,
2007. 21(3): p. 216-231.
Teklay Kidane, et al., National EPI coverage survey report in Ethiopia, 2006. Ethiopian
Journal of Health Development, 2008. 22(2): p. 148-157.
UnitedNationChildren'sFund2008,
http://www.unicef.org/infobycountry/ethiopia_statistics.html#54. accessed online on August
21, 2009.
M Melese, et al., Low vision and blindness in adults in Gurage Zone, central Ethiopia. Br J
Ophthalmol, 2003. 87: p. 677-680.
Yemane Berhane, et al., Prevalence and causes of blindness and Low Vision in Ethiopia.
Ethiopian Journal of Health Development, 2007. 21(3): p. 204-210.
Yemane B, et al., Prevalence of Trachoma in Ethiopia. Ethiopian Journal of Health
Development, 2007. 21(3): p. 211-215.
Abebe Bejiga, W.A., Prevalence of trachoma and its determinants in Dalocha District,
Central Ethiopia. Ophthalmic Epidemiology, 2001. 8(2-3): p. 119-125.
MinistryofHealth, National five-year strategic plan for eye care in Ethiopia (2006-2010).
Disease Prevention and Control Department, 2006.
Muhit, M.A., Finding children who are blind. Community Eye Health Journal, 2007. 20(62):
p. 30-31.
Muhit, M.A., et al., Causes of severe visual impairment and blindness in Bangladesh: a study
of 1935 children. British Journal of Ophthalmology, 2007. 91(8): p. 1000-4.
Muhit M A, et al., The key informant method: a novel means of ascertaining blind children in
Bangladesh. Br J Ophthalmol, 2007. 91: p. 995-999.
Kalua, K., et al., Productivity of key informants for identifying blind children: evidence from
a pilot study in Malawi. Eye, 2009. 23(1): p. 7-9.
Kalua, K., et al., Causes of blindness among children identified through village key
informants in Malawi. Canadian Journal of Ophthalmology, 2008. 43(4): p. 425-7.
Boye, J., Validating key informant method in detecting blind children in Ghana. Community
Eye Health Journal 2005. 18(56): p. 130-134.
Gilbert C, et al., Childhood blindness: a new form for recording causes of visual loss in
children. Bulletin of the World Health Organization, 1993. 71(5): p. 485-9.
Waddell K, Childhood blindness and low vision in Uganda. Eye, 1998 12: p. 184-92.
Njuguna M, et al., Causes of severe visual impairment and blindness in children in schools
for the blind in eastern Africa: changes in the last 14 years. Ophthalmic Epidemiol, June
2009. 16(3): p. 151-5.
J S Rahi, S.S., C E Gilbert, A Foster, Childhood blindness due to vitamin A deficiency in
India: regional variations. Arch Dis Child, 1995. 72: p. 330-333.
39
45.
46.
47.
48.
Alfred Sommer, K.P.W., Vitamin A Deficiency: Health, Survival and Vision. American
Journal of Epidemiology, 1998. 147(12): p. 1175-6.
G. V. S. Murthy, et al., Refractive Error in Children in an Urban Population in New Delhi.
Investigative Ophthalmology & Visual Science, 2002. 43(3): p. 623-631.
Umeh, R.E., The cause and profile of visual loss in an onchocerciasis-endemic forestsavanna zone in Nigeria. Ophthalmoic epidemiology, 1999. 6: p. 303-315.
S J Hornby, Y.X., C E Gilbert, A Foster, X Wang, X Liang, H Jing, L Wang, W Min, Y Shi,
Y Li, Causes of childhood blindness in the people's republic of China: results from 1131
blind school students in 18 provinces. British Journal of Ophthalmology, 1999. 83: p. 929932.
40
Appendices:
Appendix 1. Ethics application form
41
42
43
Appendix 2. Ethics approval letter- Local
44
Appendix 3: Consent form
Consent Form:
I, ………………………………………………………………………………………………., have read or
had read to me in my own language the attached patient information sheet and I have understood
the information in it. As a father/mother/guardian, I agreed and understood that my child is
participating in a study entitled ’’Magnitude and causes of childhood blindness/SVI at Sekoru district
of Jimma zone Southwest Ethiopia: The key informant method’’ which is conducted by Dr Berhan
Solomon Demissie, International Centre for eye health, London School of Hygiene and Tropical
Medicine, London, UK. This will involve interviews and eye examinations. My queries have been
answered to my satisfaction. I also give my permission for the publication of the child’s photographs
for all educational and fund raising purposes to control childhood blindness, but not for advertising
purposes.
Signature …………………………………
Date …………………………………………
45
Appendix 4: Patient Information Sheet
Patient Information Sheet:
Project:
Magnitude and causes of childhood blindness/SVI at Sekoru district of Jimma zone
Southwest Ethiopia: The key informant method.
Investigator: Dr Berhan Solomon Demissie
We will be very thankful if your child participates in this study. Please listen to this form carefully to
know about the rationale of this study. Please do not hesitate to ask any questions you feel for
clarification before deciding whether you allow your child to participate in the study or not. We are
ready to give you all information you want to know about.
Why to carry out this study: This study will know the magnitude and identify the causes of childhood
blindness at Sekoru district using key informants selected from your own community. This will help
to recommend ways of controlling and preventing childhood blindness in the area in the future.
Children identified as blind with treatable causes will have arrangements for free treatment at Jimma
University hospital.
This all depends on your willingness: It is totally up to you to decide whether your child participates
in the study or not. We are giving you this information and will ask you to sign on an informed
consent form if you agree. If you decide not to participate, it will not affect your medical care to you
or your family in anyway. Besides, if you agree and accept, you are still free to withdraw from the
study anytime without having any special reason.
We will give a free eye examination by an ophthalmologist and offer appropriate treatment when
needed. There will be no harm during examinations and you will be by the side of your child all the
time during the examinations. Your child’s participation in this study will help to provide better
childhood eye care services in your community in the future.
This study is undertaken as a part of a master’s degree at international centre for eye health at
London School of Hygiene and Tropical Medicine (LSHTM) and has been approved by the research
and publication committee of Jimma university hospital and ethics committee of LSHTM.
If you need any more information at any time you can contact me with the following address:
Dr. Berhan Solomon Demissie,
Jimma University Hospital,
PO Box 1761
Telephone # 251 0911 406524
Email: [email protected]
Thank you so much for your attention.
46
Appendix 5: Combined academic and risk assessment approval (CAR form)
47
48
49
50
51
52
53
54
55
56
57
58
Appendix 6. Letter of support to Sekoru district health bureau in Amharic language.
59
Appendix 7. Use of photographs consent form
60
Appendix 8. Use of photographs consent form
61
Appendix 9. Use of photographs consent form
62
Appendix 10. Use of photographs consent form
63
Appendix 11. Questionnaire form
64
65
Appendix 12. MSc project report (feedback)
66
67
68
69
Appendix 13. Curriculum for training key informants:
Job description: to look for blind or severely visually impaired children
Selection criteria:

Permanent residence in Sekoru district

Ability to read and write

Ability to speak the local language perfectly

Age not greater than 60 years
Objectives:
Following the training each key informant should able:
 To communicate with parents or guardian of a blind/SVI child
 To recognise a blind or SVI child in the community
 To do vision test at 6 metres using E-letter
 To convince parents to bring their blind/SVI child to examination centre
Teaching method:
 Lectures
 Demonstrations
 Group discussions
 Role play
Place: High schools (Sekoru, Kumbi)
Time table: total 4 hours and 30 minutes
ACTIVITY
DURATION
Introduction
15 minutes
Lecture
1 hr and 30 minutes
Break time
15 minutes
Discussion
30 minutes
Demonstrations
30 minutes
Role play
1 hour
Questions and answers
Total duration
30 minutes
4 hours and 30 minutes
70