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 Table of Contents  
Year : 2022  |  Volume : 34  |  Issue : 2  |  Page : 110-114

Role of teachers in screening of ocular disorders in school children: A multistage school screening program

1 DNB Resident, Chaithanya Eye Hospital, Trivandrum, Kerala, India
2 Department of Paediatric Ophthalmology, Chaithanya Eye Hospital, Trivandrum, Kerala, India
3 Department of Retina, Chaithanya Eye Hospital and Research Institute, Trivandrum, Kerala, India

Date of Submission28-Oct-2021
Date of Decision11-Nov-2021
Date of Acceptance08-May-2022
Date of Web Publication30-Aug-2022

Correspondence Address:
Dr. K S Aparna
Chaithanya Eye Hospital and Research Institute, Kesavadasapuram, Trivandrum - 695004, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/kjo.kjo_213_21

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Purpose: The aim of the study was to find out whether teachers can be introduced as an effective tool in ocular screening of school children and to list out various causes of visual impairment and ocular abnormalities in school children and provide appropriate measures.
Method: A multistage school screening program from August to December 2019 in Trivandrum included 33,990 students from 52 schools. Five stages of the study were training of selected teachers, screening by teachers in the school, comprehensive examination by the hospital team in schools, detailed evaluation of referred children in the hospital, and corrective measures by pediatric ophthalmologists in our hospital. A total of 1480 children were selected randomly from the children identified as normal by teachers to detect false negatives. The pattern of ocular disorders children was analyzed.
Results: Out of 33,990 students, 6343 students who were detected to have ocular disorders by teachers (18.6%) were examined by our team. 74.2% (4707 students) of them were confirmed to have ocular problems. Thus teachers were able to identify the eye problems correctly (true positives) in 74.2% children, 25.8% being false positives. True positives include refractive errors (73.4%), allergic conjunctivitis (7.9%), strabismus (1.9%), amblyopia (0.098%), pediatric cataract (0.08%), etc. Out of 1480 randomly selected children, 8 (0.54%) children were false negatives (none had refractive errors). Spectacles were given to 2484 children free of cost.
Conclusion: Simplicity of multistage screening, ease of its application, time and cost effectiveness, wider coverage, utility as a continuous process in coming years signifies that introducing teachers as primary vision screeners at their schools is an innovative community-based strategy to address the challenges of childhood blindness in resource-constrained settings.

Keywords: Childhood blindness, refractive errors, school screening

How to cite this article:
Aparna K S, Bhaskar R, Nair U. Role of teachers in screening of ocular disorders in school children: A multistage school screening program. Kerala J Ophthalmol 2022;34:110-4

How to cite this URL:
Aparna K S, Bhaskar R, Nair U. Role of teachers in screening of ocular disorders in school children: A multistage school screening program. Kerala J Ophthalmol [serial online] 2022 [cited 2023 Feb 5];34:110-4. Available from: http://www.kjophthal.com/text.asp?2022/34/2/110/355047

  Introduction Top

Childhood blindness is one of the priority targets of Vision 2020-Right To Sight due to its impact on the overall development of the child. The WHO reports that there are approximately 19 million visually impaired children in the world, and 1.4 million are blind.[1] The overall population-based estimate of prevalence of refractive errors in children in India was 8%, and from the school-based data, it was 10.8%.[2]

Childhood blindness due to various preventable causes suggests that eyecare services in the population are inadequate. Vision screening of children in schools has traditionally been done by optometrists and ophthalmologists. In most developed countries, the optometrist-to-population ratio is approximately 1:10,000. However, in developing countries, the ratio is 1:600,000 and much worse in many rural areas, up to millions.[3] In rural areas of India, only 10,000 ophthalmologists are responsible for the care of the entire population: a ratio of 1 ophthalmologist per 100,000 people.[4] This lack of practitioners is the main reason for high rates of vision problems due to uncorrected refractive error in developing countries.

Introducing teachers in school eye screening programs, especially in rural areas, can lead to effective utilization of existing resources and early detection of potentially blinding disorders in children. It will save enormous amount of time and energy of the eyecare staff, reduce their workload, and provide a wider coverage of eyecare services. This model is low-cost and has been successfully tried in parts of India, China, and Brazil.[5] It is important to know the accuracy of the screening carried out by teachers before recommending this method as an effective tool.

  Aims and Objectives Top

  1. To find out whether teachers can be introduced as an effective tool in ocular screening of school children.
  2. To list out various causes of visual impairment and ocular abnormalities in school children and provide appropriate measures.

  Materials and Methods Top

This study was a prospective multistaged clinical trial carried out over a period of 5 months from August to December 2019 in Trivandrum district, Kerala. This study included 33,990 students from 52 schools in the age of 5–15 years. The study was approved by the institutional ethics committee and followed the tenets of the Declaration of Helsinki for biomedical research. As a preparatory step, a school screening team comprising a project director, pediatric ophthalmologist, general ophthalmologist, staff nurse, optometrists, public relation officer (PRO), and camp coordinator was formed.

Trivandrum district is divided into 3 educational districts including Trivandrum, Attingal, and Neyyattinkara. Details of schools in each educational district were collected from the corresponding district educational officers. After necessary planning, the camp coordinator and PROs visited each school to brief the headmaster about the program. Following the visit, teachers willing and able to participate in the program were identified depending upon the total number of students in that school for training. The school authorities provided consent for eye examination by optometrists in their premises.

The study was done in 5 stages:

Stage 1: Training of selected school teachers

Stage 2: Screening by the trained school teachers in the school

Stage 3: Vision testing by optometrists and comprehensive ophthalmological evaluation by general ophthalmologists in the school

Stage 4: Cycloplegic refraction and detailed ophthalmologist examination in the secondary eye center for referred children

Stage 5: Surgery and visual rehabilitation by pediatric ophthalmologists in the tertiary eye center

Training of selected school teachers

273 school teachers from 52 schools in Trivandrum were invited to the training program arranged with the help of the NGO Lions Club. A total of 7 teacher's training programs, each of half-day duration, were conducted. The training was given by ophthalmologists and optometrists.

The lectures started with topics on magnitude of childhood blindness and the role of teachers in early detection of vision problems. The first half of the training program was devoted to an introduction to the anatomy and functioning of the eye and common eye problems in children. Slides, posters, and videos were presented in addition to didactic lectures. The second part of the program included practical training on how to measure visual acuity using Snellen's chart. This was practiced by the teachers among themselves.

Subsequently, each teacher repeated the whole procedure in front of the staff in order to confirm that they understood the procedure completely and also to clear their doubts. The school teachers were provided with a Snellen's number chart, a rope of 6 meters to measure the distance, and a form to fill in the details of the child including short history.

Screening by teachers

Children were asked to read the number pointed out by the teacher on the Snellen's chart from a distance of 6 meters. Children with any other ocular abnormalities or children complaining of ocular symptoms were also selected for further stages of the study.

Screening by the hospital team

On another day, within 1 month after teacher screening was completed, the hospital team screened the children selected by teachers. Six optometrists with >5 years of experience were included for the study. All children underwent vision screening by the optometrists and comprehensive examination by the ophthalmologist.

Those who were detected to have refractive error were referred to the hospital for dilated retinoscopy and fundus examination. Children with common problems such as blepharitis, allergic conjunctivitis hordeolum, etc., were give medications in the camp site. Those who needed further evaluation for cataract, ptosis, asthenopic symptoms for convergence evaluation, squint for orthoptic evaluation, etc., were also referred.

To assess the true negatives and false negatives, we conducted the second part of the screening. Approximately 5% of children who were identified as normal by the school teachers were included for examination by the ophthalmology team. These children were identified using a simple random sampling technique. Children identified as normal by the teacher but found to have abnormalities by the ophthalmology team were considered as false negatives. The data analysis was done using MS-Office Excel.

  Results Top

In the first stage of the project, 52 schools in Trivandrum district were covered. A total of 273 teachers from these schools were trained in vision screening. The project enrolled 34,274 school-going children in the age of 5–15 years. Out of these, 33,990 children (51.3% males and 49.7% females) were screened by the teachers, providing a coverage of 99.1%. They were divided into 3 categories as lower primary school (LPS, n = 8579), upper primary school (UPS, n = 7431), and high school (HS, n = 17980).

The teachers identified 6343 (18.6%) children with eye problems, who needed evaluation by an ophthalmologist. These included 24.81% LPS, 21.2% UPS, and 53.94% HS children (males 46.8%, females 53.2%). Therefore, our team had to examine only 18.6% of the total children enrolled in the project [Figure 1].
Figure 1: Comparison of the number of children examined by teachers and the hospital team

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The team confirmed eye problems in 4707 children (13.8% of the total children enrolled for the study). Thus, the teachers were able to identify the eye problems correctly (signifying true positives) in 74.2% children, remaining 25.8% being false positives [Figure 2].
Figure 2: Children identified as true positives and false positives after examination by the hospital team in stage 3 of the program

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Out of the 4707 children identified as true positives, ocular disorders among various categories were 68.5% in LPS, 78% in UPS, and 69.6% in HS children.

Out of 33,990 children, 4.35% (n = 1480) who were identified as normal by the school teachers were selected by a simple random sampling technique and re-examined by the hospital team. 8 children (0.54%) were found to have eye problems (3 blepharitis, 1 chalazion, 1 ADS, 1 corneal opacity, 1 mild ptosis, and 1 nystagmus) [Figure 3]. None of them had refractive errors.
Figure 3: Children identified as true negatives and false negatives after examination by the hospital team

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Most common presenting complaints were defective vision (15.4%), eye strain with glasses (13.4%), and headache (8.9%). Other complaints were pain, watering, floaters, lid swelling, deviation of eyes, etc [Table 1].
Table 1: Common ocular disorders identified in the true positives

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Simple myopic astigmatism was the most common refractive error (37.2%), followed by myopia (24%) and compound myopic astigmatism (19%).

Out of 4707 children diagnosed to have ocular disorders, treatment was given for conditions such as hordeolum, blepharitis, etc., and 235 were disposed in the camp. 4472 children were referred to tertiary care centers. Spectacle correction was given free of cost to 2484 children having significant refractive errors (87.9% were not using spectacles previously) [Table 2].
Table 2: Various methods of management of true-positive children are given

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  Discussion Top

Although the simplicity of vision screening by teachers has resulted in its wide coverage and acceptability, there is scanty literature available about the accuracy of the teachers in picking up subnormal vision and comparing it with a trained eyecare worker.

In our study, teachers were able to cover 99.1% of enrolled population, which indicates the organization of the entire program and the ability to involve schools and teachers, the benchmark being 80–100% that had been given by Limburg et al.[6]

In this study, the ophthalmologist had to examine only 18.6% of the total children. On an average, each teacher screened about 125 children in a year and referred about 23 children for further evaluation. Presuming that it takes 5 minutes to screen a child, each teacher is estimated to have spent 9–10 hours in a year to screen children with an additional 8 hours spent for training. This accounts to less than 18 hours in a year. On the other hand, the workload of the hospital team reduced significantly. Therefore, this method effectively utilizes time and manpower.

The effectiveness of the school screening program was assessed by the true positives, false positives, true negatives, and false negatives. In our study, 74.2% children were identified as true positives, with considerably higher sensitivity than similar studies.[7],[8],[9]

The false-positive rate in this program (25.8%) was comparatively lower than those in similar studies [Table 3], but it indicates that nearly a quarter of the referrals to the ophthalmology team were unnecessary as they had to screen these children when actually they did not need any screening. This can be sorted out by improving the quality of teacher's training, making them more confident. The over-diagnosis by the teachers may also be acceptable as this ensures that the teachers are trying to avoid missing out any child because of their doubts.
Table 3: Comparison of our study with the previous studies

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The study by Muralidhar et al.[5] showed that teacher vision screening had a low sensitivity of 24.8% in primary school children due to limited time devoted to teacher training, failure to standardize various factors such as time devoted per student by the teacher, and lack of written protocols for teachers.

The low false-negative rate in the project (0.54%) is reasonably good, supporting the premise that teachers were referring only when they were sure that the child was normal. The false-negative rate is important as it indicates the quality of training to teachers. The disorders which were missed by teachers were mild conditions, and none of them had refractive error.

One study assessed the accuracy of school nurse screening of 1719 students in Oman[11] reporting a sensitivity of 68% and a specificity 99%. School nurses, although more affordable than ophthalmic personnel, are less commonly available for screening than teachers.

Priya et al.[12] compared selected teachers (STs) to all class teachers (ACTs) and found that screening with classroom teachers identified significantly more ocular conditions, other than refractive error. The ACT model significantly increased the number of children attending follow up compared to the ST model as ACTs had the maximum interaction with students in their class.

The prevalence of refractive errors among younger school children in the present study was 10%, which lies in the mid-range (1.8–23%) reported in previous studies.[13] Uncorrected refractive errors were high in the study, and only 11.8% of children were wearing glasses similar to those reported by Rewri et al.,[14] which necessitates regular screening in children. The prevalence of other disorders was comparable to other studies.[13],[15]

  Conclusion Top

Simplicity of multistage screening, ease of its application, time and cost effectiveness, wider coverage, and utility as a continuous process in coming years signifies that introducing teachers as primary vision screeners at their schools is an innovative community-based strategy to address the challenges of childhood blindness in resource-constrained settings.

It would also be more effective in motivating the children for subsequent follow up, regular use of glasses, and monitor the impact of treatment on their performance in studies. The observation that none of the children with ametropia were missed by the teachers in this project shows that the teachers can effectively perform vision screening of children.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

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Rao GN. Ophthalmology in India. Arch Ophthalmol 2000;118:1431-2. Doi: 10.1001/archopht.118.10.1431.  Back to cited text no. 4
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  [Figure 1], [Figure 2], [Figure 3]

  [Table 1], [Table 2], [Table 3]


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