Juniper Publishers-Journal of Ophthalmology
Background:
Vision is critical for daily activities and sight is treasured by all.
Eye diseases and disorders such as uncorrected refractive errors,
cataract, glaucoma and retinopathies, tend tomar normal vision.
Purpose: To determine the prevalence of ocular conditions, their association with age and gender and the commonest associated
symptoms experienced by the basic school children in the Oforikrom sub-metropolis of the Kumasi Metropolis of Ghana.
Design: A descriptive, cross sectional survey was used.
Methods: Out of the ten sub-metros in Kumasi, simple rando
m technique was used to select a sub-metropolis. The multistage sampling technique was then used to select two public primary schools in the selected sub-metropolis as well as to identify a sample of school children aged 5-16 years. The examination procedures adopted included history-taking, visual acuity testing, plus-one blur test, static retinoscopy, subjective refraction and ophthalmoscopy.
m technique was used to select a sub-metropolis. The multistage sampling technique was then used to select two public primary schools in the selected sub-metropolis as well as to identify a sample of school children aged 5-16 years. The examination procedures adopted included history-taking, visual acuity testing, plus-one blur test, static retinoscopy, subjective refraction and ophthalmoscopy.
Results: A total of 500 children
were examined and refractive error was found to be the most prevalent
ocular condition occurring among
200 (40.0%) of the school children, followed by allergic conjunctivitis
111 (22.2%) and dry eyes 51(10.2%). The commonest symptoms
recorded include itchiness (38.40%), tearing (32.4%), red eyes (30.20%)
and headache (26%).
Conclusion: Uncorrected refractive
error was the most prevalent ocular condition and this study indicates
that the school age is a high
risk group for developing refractive errors. Eye screening of school
children is recommended and eye care services, especially, refractive
error
services should be enforced.
Key words
Ocular, Assessment, Vision, Refractive error, Screening, Symptoms, Prevalence
Introduction
Poor vision in childhood affects performance in school or at
work and has a negative influence on the future life of a child.
Moreover, planning of the youth’s career is very much dependent
on visual acuity, especially in jobs for the navy, military, railways
and aviation (Gupta et al. [1]; Brown et al. [2]).
Assessment of ocular health in children is important because
while some eye conditions are just causes of ocular morbidity,
others invariably lead to blindness. Also while some conditions
such as refractive errors and cataract are treatable others like
measles and vitamin A deficiency are largely preventable. Many
ocular diseases have their origin in childhood and the morbidity
may go unnoticed in the absence of any form of ocular assessment
because unlike adults, children have no effective means of
reporting ocular problems (Deshpange et al. [3]). Kamath et al. [4] reported that children do not complain of defective vision,
and may not even be aware of the condition. They try adjusting
to the problem of defective vision by sitting in the front benches,
holding the books close to their eyes, squeezing the eyes.
The school age is a formative period, physically as well as
mentally, transforming the child into a promising adult. As such,
health habits formed at this age will be carried to adult age, old
age and even to the next generation (Kamath et al. [4]). This
means that, not only will the child carry the effects of untreated
poor ocular health into adulthood, but also ocular hygiene and
health seeking behaviors cultivated in childhood as well.
Many ocular diseases from poor ocular health have
their
origin in childhood and the morbidity may go unnoticed and
adversely affect the child’s performance in school and may also
cause severe ocular disability in the later part of life (Deshpange et
al. [3]). According to Gupta et al. [1], school children are easily
accessible and schools are the best forum for imparting health
education to the children, and schools are also one of the best
centers for effectively implementing the comprehensive eye
healthcare program. Ocular health assessment in school children
is therefore one of the best modules in early detection and
treatment of preventable blindness in children.
Data reported worldwide suggest that there is wide regional
variation in the major causes of blindness in children; lesions
of the central nervous system predominate in the developed
countries and corneal scarring as a result of acquired diseases
predominate in poor countries (Rushood et al. [5]).
Good ocular health also ensures that school children can attain
their full potential in the course of their education (Deshpange
et al. [3]). Periodic screening of school children therefore is very
critical to improving the quality of vision in childhood. This goes
on to buttress the fact that development of visual screening
programs in elementary schools is essential to ensure early
detection and treatment of refractive errors and eye disorders.
It has been reported that poor ocular health adversely affect
the child’s performance in school and may also cause severe
ocular disability in the later part of life (Deshpange et al. [3]).
Thus, effective ocular health assessment in early life invariably
helps in preventing long-term visual disability. Another issue
of concern in poor ocular health in children is the potential of
childhood blindness. Childhood blindness affects, not the child
alone, but the entire family and many of them are left as street
beggars in the poor countries (Khalil et al. [6]). Poor ocular
health in children affects childhood development, educational
performance as well as social and employment opportunities
(Prakash et al. [7]).
The purpose of this study is to determine the prevalence
of eye diseases, their association with age and gender and the
commonest associated symptoms among basic school children in
the Oforikrom sub-metropolis of the Kumasi Metropolis of Ghana.
Material and Methods
Study area
The study was carried out in the Kumasi Metropolis in
the Ashanti Region of Ghana. Kumasi has a population of
2,035,064(http://www.statsghana.gov.gh/).It is located in
the transitional forest zone of Ghana and lies between latitude
6.35° – 6.40° and longitude 1.30° –1.35°, an elevation which
ranges between 250 – 300 meters above sea level. The land
area of the Metropolis is about 254sq/km and approximately
10 kilometers in radius. There are 119 communities and ten
(10) sub-metropolitan areas which include Oforikrom, Asawase,
Asokwa, Bantama, Kwadaso, Manhyia, Nhyiaeso, Subin, Suame,
Tafo-Pankrono (http://kma.ghanadistricts.gov.gh/).
Study type and design
A descriptive, cross-sectional study was undertaken. A sample
size of 500 basic school children aged 5 to 16 years in the Kumasi
Metropolis. Out of the ten sub-metros in Kumasi, simple random
technique was used to select one sub-metro. The multistage sampling technique was then used to select two primary schools
in the selected sub-metropolis.
Data collection technique
Data collection took place over a period of two weeks. Consent
forms were initially sent to parents/guardians of the basic school
children of the selected schools to be signed and approved before
thorough ocular examination took place. These were however
preceded by acquiring the patient’s biodata and a comprehensive
case history through questionnaires which were being filled by
themselves or by aid. The ocular examination procedure was as
follows:
Visual Acuity
Unaided visual acuity measurements were taken for each eye
of the study participants, reading from either the Snellen letter
chart or the Snellen “E” chart. Aided visual acuity was taken when
a participant presented with a spectacle correction. Pinhole acuity
was measured in patients whose visual acuities were found to be
worse than 6/6. Improvement of the patient’s visual acuity with
the pinhole, the cause of the reduction in vision could be said to
be mainly refractive in nature and the maximum improvement in
the vision could be attained by the use of lenses to correct errors
of refraction (Renner [10]).
Refraction
Staticretinoscopy and Subjective refraction were undertaken
for all the subjects whose visual acuity improved with the pinhole.
Also subjects with an uncorrected visual acuity of 6/6 were
considered emmetropic after passing the +1 Blur test. Subjects
with an error of +/- 0.25 or more were considered ametropic.
External examination and funduscopy
Examination of the external eye including the eyelashes, lids,
cornea, conjunctiva, iris and pupil and of the fundus using the
pen torch/ophthalmoscope light and the direct ophthalmoscope
were undertaken respectively.
Ethical Consideration
This research was conducted with approval from the Director
of the Kumasi Metropolitan Education Directorate, the heads of
the selected junior and senior high schools, and from the teachers
Data Analysis
The Epi Info software, version 3.5.1 was used to analyze the
data.
Results
A total of five hundred (500) pupils sampled from the study
area responded to the questionnaires. The socio-demographic
characteristics considered include gender, age, age group, school,
stage/ educational status, Visual acuity, symptoms, and diagnosis
were also included (Table 1).
From the Table 1, 241 pupils were females and 259 were
males representing 48.2% and 51.8% respectively. The age range
for the study sample was from 5 to 16 years. The mean and modal
ages were 10.07±2.58 years and 8 years respectively (Table 2-7).
Discussion
Prevalent Ocular Conditions
From this study, refractive error (40.0%), allergic
conjunctivitis (22.2%) and dry eyes (10.2%) have been indicated
to be the major eye conditions among the respondents. In a study
by Ajaiyeoba et al. [11] conducted on a total of 1,144 students,
the major ocular disorders encountered were Allergic/vernal
conjunctivitis (7.4%), Refractive error (5.8%), lid disorders
(0.6%), squint (0.3%), corneal scarring (0.3%),cataract (0.2%).
Adegbehingbe et al. [12] reported common ocular conditions
as follows: refractive error, 13.5%, infective conjunctivitis,
6.1%, chalazion, 6.1% and squint, 5.9%.In the vision-screening
project conducted by Presian et al. [13] at Baltimore, the
estimated prevalence of visual morbidity was found to be 3.9%,
3.1% and 8.2% for amblyopia, strabismus and refractive errors
respectively.
Prevalence of Refractive Errors
The commonest ocular condition identified in the present
study was refractive error. This was consistent with the findings
of Adegbehingbe et al. [12] and Presian et al. [13]. The refractive
error prevalence (40.0%) comprised 32.6% hyperopia, 7.2% myopia and 0.2% astigmatism. The prevalence of hyperopia,
myopia and astigmatism among the study sample were 4.6%,
6.9% and 14.1% respectively. Refractive error was defined in the
present study as an error of ± 0.50 D and above for hyperopia and
myopia and a cylindrical error of ≥ 0.50 D in one or both eyes, as
was similarly defined in a study by Niroula et al. [14]. Hyperopia
was the most prevalent refractive error observed in the study
(32.6%). Previous studies among different ethnic groups have
revealed myopia as the most prevalent refractive error (Shrestha
et al. [15]; Al Wadaani et al. [16]). Therefore, prevalence of the
different types of refractive errors differs for different ethnic
backgrounds.
Ocular Conditions and Gender
From the present study, prevalence rate of refractive error
was not statistically associated with gender (p=0.63520). Females
had a higher refractive error prevalence rate (20.6%) than males
(19.4%). Hyperopia, myopia and astigmatism were found to be
higher among females than males (p values of 0.45257, 0.69101
and 0.97124 respectively). Previous studies conducted in other
countries confirmed this relationship between females and
higher Refractive error prevalence (Al Rowaily et al. [17]; Al
Wadaani et al. [16] and Pavithra et al. [18]). Niroula et al. [14]
however, found the percentage of refractive errors to be more in
boys (7.59%) than in girls (5.30%). However, a study conducted
among Nepalese children found no sex difference (Pokharel et al.
[19]). The higher prevalence of refractive error among females
could be due to the fact that women’s eyes have a shorter axial
length than their male counterparts. A study by Foster et al. [20]
in which mean anterior chamber depth measured in women
was more shallow than in men of all ages (ANOVA, P< .0001)
predisposes them to hyperopia (leading to higher prevalence of
refractive error).
A statistically significant (p=0.00257) difference was
observed between females (13.6%) and males (8.6%) when the
prevalence rate of allergic conjunctivitis of both genders wereA statistically significant (p=0.00257) difference was
observed between females (13.6%) and males (8.6%) when the
prevalence rate of allergic conjunctivitis of both genders were compared. The higher prevalence rate in the females could be
attributed to the fact that Ghanaian female school children are
exposed to a lot of allergens in the environment than males, as
they are mostly responsible for activities such as sweeping and
dusting of tables and chairs in schools and at home. The rest of
the ocular conditions showed no significant variation with gender
Ocular Conditions and Age
From the study, there was no significant association between
the various types of refractive error and age. This was consistent
with the finding of Pavithra et al. [18]. Of all the ocular conditions
presented, only dry eye had a significant positive correlation with
age (p=0.00255) in this study. The positive correlation could be
from the fact that, academic activities such as attentive reading
increases with rise in class level (which is highly dependent on
age in Ghanaian primary schools).
According to Karson et al. [21], the rate of blinking when
reading has been shown to decrease significantly from a resting
blink rate of between 8 and 21 blinks per minute to an average
of 4.5 blinks per minute. Hence the eyes are prone to getting dry
as one age, moves higher in class level and do a lot of attentive
reading.
Ocular Symptoms
Amongst the commonest symptoms recorded in this study,
38.40% reported itchiness, 32.4% had tearing, 30.20% had
red eyes and 26% had headache. The high prevalence of these
symptoms could be attributed to allergens such as dust and
chalk particles in the school environment to which the school
children are exposed to. Children have strong immune systems
such that, they easily have hypersensitivity reactions to things in
their environment. The high reportage of headache as a symptom
could be attributed to the high prevalence of hyperopia within the
study population. Gleason et al. [22] have stated that hyperopes
must accommodate to see distant objects clearly and even more
so to see closely. According to Grosvenor [23], Sheard’s criterion
must be met for comfortable binocular vision. When this is not
met, asthenopic symptoms which includes headache will result.
This explains why most of the subjects reported experiencing
headaches. Similar findings were obtained in a cross sectional
study by Ajaiyeoba et al. [11].
Conclusion
Refractive error was found to be the most prevalent ocular
condition among the basic school children in the Kumasi
Metropolis affecting 200 (40.0%) pupils out of a sample of 500,
followed by allergic conjunctivitis 111 (22.2%) and dry eyes 51
(10.2%). Amongst the commonest symptoms recorded in the
research, 38.40% reported itchiness, 32.4% had tearing, 30.20%
had red eyes and 26% had headache.
The ocular diseases showed no significant variation with
gender apart from allergic conjunctivitis which had a statistically
significant difference between females (13.6%) and males (8.6%)
(p=0.00257). There was also no significant association between
eye disease and age except in the case of dry eye that had a
significant positive correlation with age (p=0.00255).
School health services should have eye care services
incorporated, implemented and strengthened effectively.
Routine eye screening and examination among school children,
especially those below the age of 9 years, should be enforced as
any unidentified eye disorder could easily result in amblyopia.
Provision of affordable corrective services should follow
screening, especially, to the school-age group.
Table 1: Age and Gender distribution of respondents.
Table 2: Visual acuity of respondents.
Table 3: Prevalence of Ocular conditions.
Table 4: Distribution of refractive state by Gender.
Table 5: Prevalence of common ocular symptoms.
Table 6: Distribution of Respondents’ Gender and Eye Disease.
Table 7: Linear Regression model showing the distribution of
Respondents’ Age and Ocular conditions
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