Table of Contents  
ORIGINAL ARTICLE
Year : 2019  |  Volume : 27  |  Issue : 1  |  Page : 17-21

Training Teachers on Vision Screening for School Children in Low-Resource Setting in Southwest, Nigeria


1 Department of Ophthalmology, Lagos University Teaching Hospital, Lagos, Nigeria
2 Me Cure Eye Center, Me Cure Healthcare Limited, Lagos University Teaching Hospital, Lagos, Nigeria
3 Department of Radiotherapy, Lagos University Teaching Hospital, Lagos, Nigeria

Date of Web Publication4-Jul-2019

Correspondence Address:
Dr. Olufisayo T Aribaba
Department of Ophthalmology, Guinness Eye Center, Lagos University Teaching Hospital, Lagos
Nigeria
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/njo.njo_15_18

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  Abstract 


Background: There is a growing recognition that school teachers can be trained to deliver simple health and screening services and refer children for treatment if they have health problems. Although it is recognized that teachers are not replacement for qualified health personnel, they can be trained to provide simple vision screening for school children. Aim: This article aims to determine the ability of trained school teachers to participate in the school eye screening program by testing visual acuity (VA) of the primary and secondary school children aged 5 to 15 years using the Snellen’s chart in Ifo, Ifo Local Government Area of Ogun State. Materials and Methods: This study was a population-based descriptive cross-sectional study conducted among school children aged 5 to 15 years from 20 primary and secondary schools in Ifo, Ifo Local Government Area of Ogun State. Forty teachers (two per school) were trained to use the Snellen’s chart to measure VA and categorize vision into normal or impaired using the VA of 6/9 in the better eye as cutoff. After enumeration, the visual acuities of the school children were measured using the Snellen’s chart by the teachers and compared with visual acuities measured by the research team. Results: A total of 1308 school children (574 boys and 734 girls) had their VA tested using Snellen’s chart by 40 teachers and verified by the research team. The sensitivity of the teachers’ VA testing was 73.6%, with a high specificity of 93.8% and positive and negative predictive values of 45.7% and 98%, respectively. The teachers’ VA measurements showed a moderate agreement with that of the researchers with a Kappa score of 0.525. Conclusion: This study shows that school teachers can be trained to participate in school eye health program. Their involvement can make the program cheaper to establish, ensuring sustainable and better coverage among the targeted student population.

Keywords: School screening, teachers, visual acuity, visual impairment, uncorrected refractive errors


How to cite this article:
Aribaba OT, Alabi AS, Alabi AO, Adenekan AO, Onakoya AO, Akinsola FB. Training Teachers on Vision Screening for School Children in Low-Resource Setting in Southwest, Nigeria. Niger J Ophthalmol 2019;27:17-21

How to cite this URL:
Aribaba OT, Alabi AS, Alabi AO, Adenekan AO, Onakoya AO, Akinsola FB. Training Teachers on Vision Screening for School Children in Low-Resource Setting in Southwest, Nigeria. Niger J Ophthalmol [serial online] 2019 [cited 2019 Nov 13];27:17-21. Available from: http://www.nigerianjournalofophthalmology.com/text.asp?2019/27/1/17/262056




  Introduction Top


Globally about 80% of all visual impairment can be prevented or cured.[1] Geographically, visual impairment is not uniformly distributed throughout the world. Approximately 90% of visually impaired people live in developing countries.[1],[2] A child with moderate visual impairment is an individual below 16 years of age who has a presenting visual acuity (VA) worse than 6/18 in the better eye.[1],[2] Presenting VA was used according to the revised World Health Organization’s definition to include uncorrected refractive error.[2] The DANIDA Support Unit (DANPCB) vision screening program uses Snellen’s VA worse than 6/9 in the better eye to define visual impairment.[3] DANPCB screening criteria is more suitable for school children because VA of 6/18 or worse is grossly subnormal for learning.[3]

The prevalence and causes of visual impairment and ocular morbidities in children depend on geographic regions, socioeconomic development, the status of primary healthcare, and the eye care services available.[3] In the United States, visual disorders are the fourth most prevalent class of disability and the most prevalent handicapping conditions in childhood, affecting nearly 13.5 million children.[4] The US preventive services task force has identified that visual impairment in young children affects 5% to 10% of all preschoolers.[4]

Previous studies that assessed the eligibility of school teachers to participate in providing the initial component of eye screening to their pupils recorded high success rate.[5],[6],[7],[8],[9] These studies elucidated that using school teachers to provide the initial component of school screening could relieve the burden on the limited ophthalmic services available in most of the countries, reduce the cost and time of organizing a school eye screening, and make easy the incorporation of eye health into the school health program.[5],[6],[7],[8],[9] There is a growing recognition that teachers can be trained to deliver simple health screening services and refer children for treatment if they have health problems. Although it is recognized that teachers are not replacement for qualified health personnel, they can be trained to provide vision screening for school children.[9] Despite the high success rate recorded in the participation of nonophthalmic personnel in school eye screening programs from previous studies, it is imperative that we keep re-emphasizing the need and expanding the knowledge about school eye screening among nonophthalmic personnel.

Visual impairment is a significant cause of morbidity in children worldwide.[2] The effect of visual problems on a child’s development depends on the severity, type of loss, and the age at which the condition appears. Children with visual impairment may need additional help with special learning and teaching equipment with modification in the regular school curriculum to emphasize listening skills, communication, orientation, mobility, vocation, career options, and daily living skills.[10]

The purpose of this study is to determine the ability of trained school teachers to participate in the school eye screening program by testing VA using the Snellen’s chart among primary and secondary school children aged 5 to 15 years in Ifo, Ifo Local Government Area of Ogun State, Nigeria.


  Materials and Methods Top


The study was a school-based descriptive cross-sectional study that used a quantitative method of data collection and was carried out over a 6-week period between the months of May and June 2013. The study was conducted among school children aged 5 to 15 years attending primary or secondary schools in Ifo, Ifo Local Government Area of Ogun State. Normal vision was defined as presenting distant VA of 6/9 or greater in the better eye. While impaired vision was defined as presenting distant VA worse than 6/9 in the better eye, it was classified into mild (6/12–­­6/18), moderate (<6/18–6/60), and severe (<6/60–3/60) by the research team using the revised visual impairment classification.[11]

There were eight public secondary schools, eight public primary schools, two private secondary schools, and two private primary schools selected for the study. Stratified sampling technique by proportional allocation was used to determine the number of students and pupils from the 20 schools selected for the study. This was done by dividing the number of children aged 5 to 15 years in each school by the total sum of children aged 5 to 15 years in the 20 schools, multiplied by the sample size.

Ethical clearance from the Health Research and Ethics Committee of the Lagos University Teaching Hospital and permission from the Ministry of Education Abeokuta, Ogun State, were obtained for the study. Informed consent was also obtained from the parents or guardian of all participating children through signed or thumb-printed consent letters sent to them.

Two teachers per selected school were picked to participate in the survey and they underwent training. The training was a day-long workshop that included teaching and practical sessions. They were trained on how to ask simple questions to identify children with impaired vision, measure 6 m for VA testing, properly occlude the eye, make and use pinhole, and measure accurate and reproducible distant VA using the Snellen’s chart.

The training also included how to record VA correctly, interpret the VA measured, and use the interpreted values to categorize vision into normal or abnormal/impaired. A pilot study was conducted in two schools not selected for the actual survey.

The teachers measured the distant unaided VA and categorized the respondents’ vision into normal or impaired; the research team also did the same for all respondents in a separate room. The data were entered into a database and analyzed using the Statistical Package for Social Sciences software (IBM SPSS version 20, Chicago, IL, USA). The research team’s VA results were used as reference standard to calculate the sensitivity, specificity, and positive and negative predictive values of the teachers’ VA testing. The Kappa score was also calculated to test the level of agreement between the results of the teachers and the research team.


  Results Top


All the 40 recruited teachers (two per school) participated in the study. There were 23 female (57.5%) and 17 male (42.5%) teachers. A total of 1308 children were examined in the survey representing 94.5% of the 1384 children enrolled for the study. The mean age was 12.03 years ± 2.57 standard deviation, with age ranging from 5 to 15 years as per the last birthday of the respondents; 309 respondents were aged between 5 and 10 years, whereas 999 respondents were aged between 11 and 15 years.

All the 1308 respondents had their distant VA tested by the teachers using the Snellen’s chart and retested by the research team.

[Table 1] shows the sex distribution. There were more female respondents 734 (56.1%) than male respondents 574 (43.9%), with an overall female to male ratio of 1.3:1.
Table 1 Profile of the 1308 respondents attending schools in Ifo, Ifo Local Government Area

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Four hundred and forty-six children screened were in primary schools and 862 were in secondary schools. We had children from both public and private schools in the study; 1071 children were in public schools and 237 children were in private schools.

Only twenty-five (1.9%) of the respondents had any form of eye examination before starting school; 22 (88.0%) of them in a clinic setup and the remaining 3 (12.0%) during a free eye screening exercise.

The teachers after VA testing with Snellen’s chart categorized 1168 (89.3%) children having normal vision and 140 (10.7%) children having impaired vision, whereas 1221 (93.3%) children were categorized with normal vision and 87 (6.7%) children with impaired vision by the research team, as depicted in [Figure 1].
Figure 1 Pie chart showing the visual grading of the respondents as measured by the research team.

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Among the 87 respondents with impaired vision as measured by the research team, 61 (70.1%) had mild impairment, 19 (21.8%) had moderate impairment, and 7 (8.0%) had severe impairment, as depicted in [Figure 2].
Figure 2 Distribution of visual category by teachers and research team.

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[Table 2] shows that out of the 1221 respondents identified by the research team with normal vision (VA of 6/9 or better), the teachers correctly identified 1145 (93.8%; true negatives). Out of 87 respondents who had impaired vision (VA < 6/9 in the better eye) according to the research team, the teachers correctly identified 64 (73.56%; true positives).
Table 2 Comparison of teachers’ and research team’s visual acuity category

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A Kappa score of 0.525 (P = 0.000) was generated using [Table 2], which shows a moderate agreement between the results of the research team and the teachers.

[Table 3] showed that the teachers achieved a sensitivity of 73.56% and a specificity of 93.78% using the results of the research team as the gold standard.
Table 3 Sensitivity, specificity, positive, and negative predictive value of teachers’ visual acuity test

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[Table 3] further showed positive and negative predictive values of 45.7% and 98.0%, respectively, of the teachers’ results using the results of the research team as the gold standard.


  Discussion Top


The study recorded 100% participation among the trained teachers recruited for the program in the 20 schools where the screening took place. This perfect participation may be explained by the excitement among these teachers in being able to contribute to the well-being of their pupils, and also having the opportunity to practice what they had learnt during the pre-survey training.

The three major approaches to identify children with vision problems are school-based vision screening, and community-based and comprehensive eye examination in a health facility.[12] However, in our study, none of the school children had school-based screening as it was not available, whereas only 25 (1.9%) of the total number seen had any form of eye evaluation either in a clinic setup or during a community-based free eye screening program they were privileged to attend.

Although eye screening programs are mandatory and routinely conducted in preschool and school children in most developed countries,[12] it is neither available nor compulsory for school entry in most of the schools in our country. The limitation of resources and paucity of trained health personnel would have impeded full coverage if preschool and routine school eye screenings were to be compulsory in schools in developing low-resource setting such as ours. The training and involvement of school teachers in school eye screenings would obviously be helpful in any attempt to implement compulsory preschool and regular eye screenings in our schools.

The result of the VA testing by the trained school teachers in our study compares favorably with other similar studies done elsewhere. The sensitivity of 73.56% of this study agrees with the studies done in India[7] and Tanzania[5] having sensitivities of 71% and 70%, respectively, whereas studies conducted in Kaduna[6] and Port Harcourt,[8] two places in Nigeria, recorded lower sensitivities of 59.1% and 53.3%, respectively. The differences may be due to variations in methodology and definitions used, as those studies trained teachers to use a lower cutoff of VA < 6/12 and <6/18 in Kaduna and Port Harcourt, respectively, compared to the cutoff of VA < 6/9 used in our study.

However, the specificity of 93.78% in our study agrees with the studies in India,[7] Tanzania,[5] Lagos,[9] and Port Harcourt[8] with specificities of 94%, 93%, 85.1%, and 98.4%, respectively. This indicates that the trained teachers were able to identify children with normal vision with a high degree of accuracy.The positive predictive value of teachers’ VA testing in this study was 48.9%, indicating that a little less than half of the children identified by the teachers as having impaired vision actually had it. On the other hand, the negative predictive value was 98.0%, suggesting that almost all children identified as having normal vision by the teachers actually had normal vision. This compares favorably with the study conducted in Kaduna,[6] in which a low positive predictive value of 47.4% and a high negative predictive value of 97.9% was observed. This is slightly different from the study in Port Harcourt[8] that reported a high positive predictive value of 78.3% and a comparable negative predictive value of 94.7%. The Kappa score of 0.525 in our study agrees with the Kappa score of 0.604 reported in the study conducted in Port Harcourt.[8]


  Conclusion Top


This study shows that school teachers can be trained to participate in school eye health program. Their involvement will make the program cheaper to establish, and enhance sustainability and better coverage of the population of interest in a poor socioeconomic resource setting like ours. Furthermore, the involvement of school teachers would help in improving early detection and treatment of potentially blinding conditions that may be present among their students or pupil. The school eye health service should provide pre-entrance screening for all new intakes, periodic screening for old pupils, and prompt referral service for children who may require further ophthalmic evaluation. The study therefore recommends that teachers should participate in school eye screenings after undergoing appropriate training with sustainable ownership by the state and local school authorities, head teachers and teachers, parents and students, as well as the community.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
World Health Organization. Visual Impairment and Blindness. WHO Factsheet number 282. August 2014. Available at: http://www.who.int/mediacentre/factsheets/fs282/en. (Cited March 2018).  Back to cited text no. 1
    
2.
Gilbert C, Foster A. Childhood blindness in the context of Vision 2020-The Right to Sight. Bull World Health Org 2001;7:227-32.  Back to cited text no. 2
    
3.
DANIDA Support Unit (DANPCB) vision screening in school children − a training module. 1992. p. 5.  Back to cited text no. 3
    
4.
Vision Screening for Children Expert Workgroup. Vision screening of children in public schools − Final Report. Washington State Department of Health. December 2006. Available at: https://www.uspreventiveservicestaskforce.org. (Cited March 2018).  Back to cited text no. 4
    
5.
Wedner SH, Ross DA, Balira R, Foster A. Prevalence of eye diseases in primary school children in a rural area of Tanzania. Br J Ophthalmol 2000;84:1291-7.  Back to cited text no. 5
    
6.
Abubakar S, Ajaiyeoba AI. Vision screening in Nigerian school children. Nig J Ophthalmol 2001;1:1-5.  Back to cited text no. 6
    
7.
Limburg H, Vaidyanathan K, Dalal HP. Cost-effective screening of school children for refractive errors. World Health Forum 1995;160:173-8.  Back to cited text no. 7
    
8.
Tabansi PN, Anochie IC, Nkanginieme KEO, Pedro-Egbe CN. Evaluation of teachers’ performance of vision screening in primary school children in Port Harcourt Nigeria. Nig J Ophthalmol 2009;17:27-31.  Back to cited text no. 8
    
9.
Faderin MA, Ajaiyeoba AI. Refractive errors in primary school children in Nigeria. Nig J Ophthalmol 2001;9:10-4.  Back to cited text no. 9
    
10.
Taylor HR. Refractive errors: Magnitude of the need. J Comm Eye Health 2000;13:1-2.  Back to cited text no. 10
    
11.
Dandona L, Dandona R. Revision of visual impairment definitions in the international statistical classification of diseases. BMC Med 2006;4:7.  Back to cited text no. 11
    
12.
Castanes MS. The underutilization of vision screening for amblyopia, optical anomalies and strabismus among pre-school age children. Bonocul Vis Stabismus Q 2003;18:217-32.  Back to cited text no. 12
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

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