Causes of Visual Impairment in the Bolgatanga Municipality in the Upper East Region of Ghana
Justice Ablordey Akpabla1* and Isabel Signes-Soler1,2
1Department of Optometry, School of Advanced Education, Research and Accreditation, S.L, (SAERA), Spain
2Department of Optics and Optometry and Vision Sciences, University of Valencia, Valencia Spain
Submission: March 05, 2019; Published: April 01, 2019
*Corresponding author: Justice Ablordey Akpabla, Department of Optometry, School of Advanced Education, Research and Accreditation, S.L, (SAERA), Spain
How to cite this article: Justice Ablordey Akpabla, Isabel Signes-Soler. Causes of Visual Impairment in the Bolgatanga Municipality in the Upper East Region of Ghana.JOJ Ophthal. 2019; 7(4): 555718. DOI: 10.19080/JOJO.2019.07.555718
Objective: To profile the causes of visual impairment in the Bolgatanga municipality.
Method: A retrospective study was conducted at the Presbyterian Regional Eye Hospital in Bolgatanga, Upper East region from October 2017 through April 2018. New cases aged 6 years and above, were included in this study based on presenting distance visual acuity. The variables, presenting distance visual acuity, primary diagnosis, refractive error status and demographic data were obtained from patients’ records and analyzed using SPSS, Version16.2 (version 16.2, SPSS, Inc., Chicago, IL, USA). The data obtained were analyzed descriptively while a Chi-squared test was used to analyze the strengths of association between qualitative where P<0.05 denoted a statistical significance.
Results: Out of the 4659 new cases reviewed, 1323 were included in the study giving an overall calculated prevalence of visual impairment of 28.4%. The mean age was 60.44±19.66 years. The prevalence rates of the different grades of visual impairment were found to be: 63.9% for moderate visual impairment (MVI), 4.9% for Severe Visual Impairment (SVI), and 28.9% for blindness. The leading causes of low vision were cataract, uncorrected refractive error, glaucoma, and corneal-related disorders while the main causes of blindness were cataract, glaucoma, and corneal-related disorders.
Conclusion: There is a high prevalence of visual impairment in the Bolgatanga Municipality and most of the causes are treatable. Older age, unemployment, being a female (gender) and being a widow/widower (marital status) are the socio-demographic risk factors identified.
Visual impairment is a public health problem with devastating effect on the quality of life of affected persons. It presents educational, occupational and social challenges, with affected persons being at a higher risk of behavioral, psychological and poor social integration [1-3].
The global distribution of visual impairment and blindness is disproportionate with the Sub-Saharan African region having higher prevalence rates. The Western Sub-Saharan Region, of which Ghana is one of the 19 countries, is second to Southern Asia in the global regional prevalence of blindness and visual impairment (5.58%) with major causes identified as: Uncorrected Refractive error (41.36%), Cataract (33.44%), Glaucoma (4.94%), Age Related Macular Degeneration (2.90%), Trachoma (2.58%), Corneal Opacities (2.41%), Others (11.96%) [3-5].
The Ghana National Blindness and Visual Impairment Study (GBVIS), 2015, estimated the prevalence of blindness and severe
visual impairment in the country at 0.74% and 1.07% respectively with high prevalence in the rural areas (0.79%) than in the urban areas (0.67 %). Cataract (54.8%) followed by glaucoma (19.4%) were identified as the main causes of blindness. Uncorrected refractive error (44.4%), followed by cataract (42.2%) were identified as the main causes of visual impairment .
One major limitation in the elimination of avoidable visual impairment is the paucity of data on the causes of visual impairment in the different populations and age groups [7-9]. This study seeks to profile the causes of visual impairment in the Bolgatanga Municipality in the Upper East region of Ghana, which will serve as a baseline in designing programs and policy interventions.
The Upper East region is located in the North-Eastern corner
of Ghana between Longitude 0° and 1° West and Latitudes 10°
30”North and 11°North, within the Meningitis Belt of Africa and
the Savannah blinding onchocerciasis belt of West Africa [11,12].
About 87% of the population of the region is rural and scattered in
dispersed settlements . The region is divided into 15 administrative
districts with Bolgatanga municipal as its capital, which
is also the center of population in the entire region with a population
size of 131,550 in the year 2010 . There are nine eye care
facilities in the region, among which the Presbyterian Regional
Eye Hospital in the Bolgatanga Municipality, has a complete team
of eye care professionals (a visiting Ophthalmologist, Optometrist,
Ophthalmic nurses, and Optician), and thus serves as a primary
and a referral eye care center within the entire region, hence was
selected for this study.
Only new cases were included in this study. This is to determine
the true burden and causes of visual impairment within the
municipal among eye care seekers. Based on the daily out-patient
attendance, an estimated population of about 3000 records was
expected. The categorization of visual impairment used was based
on the 10th revision of the International Statistical Classification
of Diseases, Injuries and Causes of Death (ICD - 10, 2016) .
A total of 4659 records of new cases that had undergone comprehensive
ophthalmic examinations: distance and near visual
acuity testing, slit lamp bio-microscopy (anterior and posterior
eye examination) examination, intraocular pressure measurement,
automated visual field testing (for those suspected of Glaucoma),
objective refraction, subjective refraction were reviewed
for the period of October, 2017 through to April, 2018. A total
sample of 1323 cases, aged 6 years and above, with a presenting
distance visual acuity of 6/18 or worse in the better seeing eye
with or without correction, and or a presenting distance visual
acuity better than or equal to 6/12 in the better seeing eye but
near visual acuity worse than N8, were included in the study [2,3].
The variables: age, gender, marital status, occupation/employment
status, and health care affordability/ health insurance membership,
presenting visual acuity, primary diagnosis and refractive
error status, were obtained from patients’ records.
The study was in accordance with the Belmont Report which
promotes respect for persons, beneficence and justice. Based on
the International Ethical Guidelines for Epidemiological Studies
recommendations,  an ethical clearance was obtained from
the Navrongo Health Research Centre, an Institutional Review
Board. Further official permission was obtained from the administration
of the Presbyterian Eye Hospital for access to the facility’s
out-patient records. To ensure the confidentiality and anonymity
of data collected and the patients’ names, chart numbers,
and any form of identification were not recorded or included in
the data collected and the analysis.
A Statistical Package for Social Sciences (version 16.2, SPSS,
Inc., Chicago, IL, USA) was used to analyse the data collected
descriptively while a Chi-squared test was used to analyse the
strengths of association between qualitative where P<0.05 denoted
a statistical significance.
Out of the 4659 new cases reviewed, 1323 were included in
the study which gave us an overall calculated visual impairment
prevalence of 28.4%. The distributions of prevalence and causes
of visual impairment in the study are shown in Tables 2 & 3 respectively.
The causes of visual impairment among Health Care
Services Coverage are depicted in Figure 1.
Others = Severe Vernal Conjunctivitis, Uveitis and Phthisis Bulbi.
Others = Severe Vernal Conjunctivitis, Uveitis and Pthisis Bulbi.
BN= Blindness; NVI= Normal Visual Impairment; MVI= Moderate Visual Impairment; SVI= Severe Visual Impairment; RE= Refractive Error; AMB=
Amblyopia’; ARMD= Age Related Macular Degeneration; ChRD= Chorioretinal Degeneration; CRD= Corneal Related Degeneration; TT= Total.
The distribution of prevalence of visual impairment among
age groups is depicted in Figure 2. This distribution of visual
impairment among age groups was significant at chi square =
2.039E2, p < 0.01. Uncorrected Refractive Error was the major
cause of visual impairment among the 6-20 (5.2%) age group, followed
by the 41-50 (4.5%), 31-40 (2.9%), and the 21-30 (1.8%)
age groups respectively. Cataract was the main cause of visual impairment
among the older ages. The prevalence of Glaucoma was
observed to increase with increasing age: 0.5% in the 6-20 age
group steadily to 9.9% in the 61 and above age group. A case of
Amblyopia (0.1%) was recorded in the 6-20 age group.
Age and gender greatly influence marital status . In the
Bolgatanga municipal, females generally marry earlier than males
. Females globally, and in Ghana had been observed to live longer
than their male counterparts . This made them vulnerable
to Visual Impairment (VI) than males [3,4]. The results showed
that married persons recorded more visual impairment 55.7%
(MSVI 37.1% and blindness 16.5%) and 2.1% near low vision, followed
by the widows/widowers 33.0% (MSVI 21.7% and blindness
11.3%), and 0.1% near low vision. The divorced persons had
the least record of 1.1% (MSVI 0.7% and blindness 0.3%) and
0.2% near low vision.
About (n= 492, 37.2%) cases of visual impairment were found
among Housewives/Unemployed of which 18.2% had MVI, 16.6%
had blindness, 2.3% had SVI and 0.1% had near low vision. This
was followed by Farmers who had (n = 389, 29.4%) of the visual
impairment cases where 19.3% had MVI, 9.1% blindness, 0.9%
SVI and 0.1% had near low vision. Students and Traders both had
the same number of cases (n = 103, 7.8%) where 9.8% MVI was
found in Traders whereas 6.5% was found among Students; 0.7%
SVI in Students and 0.4% in Traders, and 0.5% blindness in Students
and 0.4% blindness among Traders. The Self Employed had
the least cases of visual impairment of (n= 25, 1.9%) of which MVI
form the majority with 1.2%, and blindness and near low vision
each were 0.3%. The distribution of prevalence of visual impairment
among types of Occupation/Employment was significant at
chi square = 3.381E2 p<0.01.
323 Cataract cases were found among Housewives/Unemployed,
followed by Farmers with 207 cases, Traders 49 cases, Retired
and Artisans both had 27 cases each.72 cases of uncorrected
refractive error were noticed among Students, followed by 38
cases in Farmers, 30 cases in Traders and 29 in Civil Servants. 84
cases of Glaucoma were found in Housewife/Unemployed, 79 in
Farmers, Students-Traders-Artisans each had 10 cases while the
Retired had 8 cases. 48 cases of Corneal Related Disorders were
found among Farmers, followed by 41 cases in Housewife /Unemployed,
12 cases in Traders and 9 cases in Artisans.
The distribution of Refractive Error among Level of Visual Impairment
is shown in Figure 5. The distribution of Level of Visual
Impairment among types of refractive error was significant chi
square = 9.794E2, p<0.01.
Of the 4659 new cases reviewed, 1323 were included in our
study which gave us an overall calculated visual impairment prevalence
of 28.4%. This was slightly lower than what was reported
by Ansah, in the Juaben study where visual impairment prevalence
of 31.9% (MSVI 28.2% and blindness 3.7%)  was reported.
This difference may be because, unlike our study, all cases (old
and new) seen within the study period, were included in the Juaben
study. The mean age of our study was 60.44±19.663 years.
This showed that visual impairment in the municipality was common
among the older persons. This agreed with the global trend
where, increasing age and population, coupled with higher life expectancy
have been noted to be associated with increasing prevalence
rates of visual impairment .
The estimated prevalence of low vision and blindness was
68.5% and 28.9% respectively. These were relatively higher
than those reported in most studies done in Ghana. In two hospital-
based studies: in determining the pattern of ocular conditions
among patients who attended the Salvation Army Eye Clinic
in the Ashanti region of Ghana, Mireku, reported 40.73% and
15.01% prevalence rates of low vision and blindness respectively
 and in determining the prevalence and causes of visual impairment
and blindness among eye clinic patients at the Juaben
Hospital, Ansah reported 28.2% and 3.7% prevalence rates of visual
impairment and blindness respectively  whiles in a population-
based study conducted by Guzek et al.  in the Volta
region, they reported 13.4% and 2.8% prevalence rates of visual
impairment and blindness respectively  and 17.1% and 1.2%
prevalence rates of visual impairment and blindness was reported
in the Tema Eye survey by Budenz et al.  We found the prevalence
of normal/mild visual impairment to be 2.6%, which was
mainly due to Presbyopia (2.5%).
We found, Cataract 664 (50.2%), Uncorrected Refractive Errors
260 (19.7%), Glaucoma 211 (15.9%) and Corneal Related
Disorders 129 (9.8%) as the main causes of visual impairment.
The other causes were: Chorioretinal degeneration 26 (2.0%),
ARMD/Macular degeneration 20 (1.5%) and Others 12(0.9%).
This trend is consistent with that reported by Ansah in the Juaben
hospital study where Cataract (39.05%), uncorrected refractive
error (21.60%) and glaucoma (18.34%) were reported as
the leading causes of visual impairment . However, the Ghana
blindness and visual impairment study observed and reported
a different trend which is consistent with the observation made
in the global estimates of prevalence of visual impairment in the
Western Sub-Saharan region , where uncorrected refractive
error(44.4%), cataract (42.2%), posterior segment(8.9%) and
glaucoma and corneal opacity each(2.2%)  were the main
causes of visual Impairment. In determining the pattern of ocular
conditions among patients who attended the Salvation Army Eye
Clinic in the Ashanti region of Ghana, Mireku reported cataract
(24.40%), glaucoma (9.70%) and uncorrected refractive error
(8.90%)  as the main causes of visual impairment which is
a similar trend observed by Guzek et al.  in their work in the
Volta region of Ghana .
The major causes of blindness found in our study were: Cataract
15.3%, Glaucoma (9.1%), and Corneal Related Disorders
(2.6%). This is similar to what was reported in the Ghana Blindness
and Visual impairment study where cataract (54.8%), glaucoma
(19.4%) posterior segment (12.9%), and corneal opacity
(11.2%) were the main causes of blindness . A clinic-based
survey of blindness and eye disease in Cambodia also reported
similar trend of causes of blindness  save that, in our study,
Trachoma, Childhood blindness and Onchocerciasis were not
found. However, Ansah , reported Glaucoma (65.91%), Cataract
(22.73%), as the causes of blindness similar to what was reported
in a population-based study in the Wenchi District by Moll et al.
, Whiles Oye et al.  reported pos¬terior segment diseases,
cataract and optic atrophy as the major causes of blindness. These
differences could be because; our study was hospital-based, hence
bias to health seeking persons thus high records of case presentations.
There were no presentation of trachoma and onchocerciasis
in our study despite the Upper East region lying within the
Meningitis Belt of Africa as well as the Savannah blinding Onchocerciasis
Belt of West Africa [11,12]. This observation could be attributed
to the success of the antibiotic distribution and treatment
in eliminating these two infectious eye diseases, to which a recent
announcement by WHO, declared Ghana the first country within
WHO Africa Region to eliminate trachoma .
Age and gender each were found to be associated with visual
impairment in our study at p<0.01. This observation is consistent
with what was reported in the global estimates of prevalence of
visual impairment , as well as other surveys across Africa and
Asia [8-10], where higher visual impairment prevalence rates
have been reported for the aged. This increase in prevalence could
be because most of the causes of visual impairment are chronic
and age-related. In all age groups, we found more females than
males and this difference was significant at p= 0. 044. This could
be attributed to the fact that, females have been reported to have
relative high longevity than males [3,4]. Thus, older age and being
a female are high-risk factors of visual impairment in the Bolgatanga
Municipality of the Upper East region of Ghana.
Employment related disparities exist in both develop and developing
countries . In an exploratory quantitative study to
understand the relationships among disability, gender and employment
in Northern Ghana by Naami A, of which Upper East
was part, it was reported that, many persons with disabilities
were unemployed, and the majority were women . This was
evident in our study where the majority of people with visual impairment
were in the unemployed/housewife category, of which
the majorities were females. The majority of farmers from our
study were females whereas in the study to determine the prevalence
and causes of visual impairment and blindness among cocoa
farmers in Ghana by Boadi et al.  more male cocoa farmers
were reported. We also recorded more male artisans /trade workers
than females which were consistent with the male - female ratio
of mechanics reported in the Cape Coast metropolis by Abu et
al.  in their work. We found cataract (which was more among
the unemployed/housewife) to be the major cause of visual impairment
followed by uncorrected refractive errors (which were
more among students), glaucoma, and corneal related disorders
(which were more among Farmers). Boadi et al.  in the work,
prevalence and causes of visual impairment and blindness among
cocoa farmers in Ghana, they reported anterior segment disorders (pterygium 23.7%, allergic conjunctivitis 9.7% and corneal scar/
opacity 6.1%) and cataract as the main causes of visual impairment:
with Posterior segment conditions and uncorrected refractive
errors as the Major Causes of Low Vision (MSVI) and legal
blindness. In a study to assess ocular health and safety among mechanics
in the Cape Coast metropolis by Abu et al.  refractive
errors, cataracts, and macular scars were reported as the causes
of visual impairment. MVI was the highest form of visual impairment
followed by Blindness, and SVI among the various types of
occupation with the near low vision being the least in our study.
Refractive error was the second cause of Visual Impairment
(VI) in our study. However, Abokyi et al.  in their work visual
impairment attributed to uncorrected refractive error among the
Ghanaian youth, reported refractive error and corneal opacity to
be the main causes of VI and corneal opacity as the main cause
of blindness. In the prevalence and causes of blindness and low
vision among adults in Fiji, Ramke et al.  reported uncorrected
refractive error as the cause of low vision. A total of 29 (6.7%) respondents
with refractive errors as the main cause of VI were reported
by Abu et al.  among mechanics in the Cape Coast Metropolis,
whereas we recorded 260 (19.7%) cases of uncorrected
refractive. The observed distribution of types of refractive error
by Abu et al.  was astigmatism, hyperopia and myopia which
is consistent with what we found in our work. However, in the pattern
of ocular conditions among patients attending an eye clinic in
Ghana study by Mireku , myopia, astigmatism and hyperopia
was the trend of distribution of types of refractive error observed.
We found the prevalence of normal/mild visual impairment to be
2.6%, which was mainly due to Presbyopia (2.5%). This prevalence
of Presbyopia was lower than that reported in several studies
across Africa: 25.11% prevalence of presbyopia was reported
by Kahaki et al.  in Mbeere District of Kenya, 68.1% reported
by Kumah et al.  in Kumasi among public senior high school
teachers, 25.9% reported by Abu et al.  among mechanics in
cape coast and 70.9% as reported by Emerole et al. in Oweiri Nigeria
. The reason for the differences in prevalence of Presbyopia
in our study and the other studies, may be due to the differences
in the type of population studied.
A major limitation of this study was that, as a hospital-based
study, findings and comparisons related to visual impairment do
not represent the true state of the entire municipality, since those
who were included in the study were those who could afford eye
Uncorrected refractive error being the second cause of VI in
the general population and main cause of VI among younger age,
aside cataract (which is covered under the NHIS), a community
and School Eye Screening of children for refractive errors and education
on awareness and benefits of spectacle corrections so as
to remove cultural barriers to compliance is highly recommended.
There is a high prevalence of visual impairment in the Bolgatanga
Municipality with cataract, uncorrected refractive error,
glaucoma, and corneal related disorders, as the major causes.
Older age, unemployment, being a female (gender) and being a
widow/widower (marital status) are the socio-demographic risk
Our gratitude goes to the Navrongo Health Research Centre,
Institutional Review Board for the ethical clearance and approval
to carry out the work. Also, to the administration of the Bolgatanga
Presbyterian Regional Eye Hospital for granting us access to
patient data and the facility as a study center. Special thanks to Dr.
Albert Kum Brown, the Optometrist at the Presbyterian Regional
Hospital, Bolgatanga, also to the Optician, the record staff and all
who have assisted in ways to the success of this work. A special
thanks to faculty members of the School of Advanced Education,
Research and Accreditation, and Dr. Kwaku Antwi Osei, for commenting
and shaping the manuscript.