International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

Original article Refractive errors as a cause of childhood blindness in school going children of a rural set-up

Pradnya L. Samant 1, Surekha V. Bangal 2, Purushottam A. Giri 3, Akshay J. Bhandari 4

1Intern, 2Professor, 4Asst. Professor, Department of Ophthalmology, 3Professor, Department of Community Medicine (PSM), Rural Medical College of Pravara Institute of Medical Sciences (Deemed University), Loni, Maharashtra, India Corresponding Author: Dr. Pradnya L. Samant

Abstract : Objectives: The study was done to determine the prevalence and causes of low vision in school going children and to assess the pattern of refractive errors and prevalence of common ones. Materials & Methods: A prospective observational study was carried out in school children of rural area, to find out the prevalence of refractive errors by vision screening programme. Primary screening was carried out by trained teachers of the school. During two months of study period, 1220 students of age group 10-12 years were screened to find out the refractive errors. Results: A total of 1220 school going children of standard 5 th , 6 th and 7 th were screened for using Snellen’s charts. Out of the total 1220 children screened, 721 were boys and 499 were girls. Total of 266 children had defective vision, out of which 128 (25.65%) were girls and 138 (19.14%) were boys. The total incidence of in the screened population of school going children was 21.80%. Amongst this, the incidence of (17.13%) is high as compared to that of hypermetropia (4.67%). Conclusion: There is need for awareness among the community about the ocular health. Vision testing must be added in the schedule of child health programme implemented by government. Annual school health check-ups must focus their attention towards vision impairment due to refractive errors and affected children should get visual aids. Key words: Refractive error, Childhood blindness, Myopia, Hypermetropia,

Introduction: better eye. 1 It can also be defined as visual field of Majority of the population in India, still lives in rural less than 10 degree irrespective of visual acuity. 1 areas. Health consciousness is much less in the rural According to WHO, childhood blindness refers to a population as compared to its urban counterpart. group of diseases and conditions occurring in World Health Organization (WHO) in 1999 proposed childhood or early adolescence, which if left a programme VISION 2020: RIGHT TO SIGHT. It untreated, result in blindness or severe visual plans to decrease the ocular morbidity among the impairment that are likely to be untreatable later in people, by eliminating the treatable causes of life. It is estimated that 1.4 million children are blind blindness. Blindness can be defined as a vision of worldwide out of the total 45 million blind people. 1 less than 3/60 in the better eye or an inability to count The prevalence of childhood blindness ranges to fingers at a distance of 3 meters in daylight in the about 1.5/1000 in developing countries, whereas it is

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International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

0.3/1000 in well affluent countries. 2 The causes of to treatment and follow-up. The children having other childhood blindness vary and include corneal ocular problems such as , and scarring, , , refractive error. 2 In were excluded. The study was done to India main causes of blindness in childhood can be determine the prevalence and causes of low vision in refractive errors, , congenital school going children and to assess the pattern of abnormalities and retinoblastoma. Refractive error refractive errors and prevalence of common ones. In contributes about 19% of the total blindness this study health education about prevention and worldwide. 3 Refractive error is an optical defect correction of these refractive errors was also done. intrinsic to the eye which prevents the light from A pretested questionnaire was used to collect the being brought to a single point focus on the , information from the students. Primary screening was thus reducing normal vision. Refractive errors are carried out in the school setting with the use of common in children and are easily correctable, Snellen’s charts after obtaining verbal informed usually with the use of the spectacles. This is the consent from the parents or school authorities. The commonest cause of around the children, who were found to have defective vision or world. other associated ocular problems with asthenopic The majority of the population in rural areas is symptoms, were referred to Medical College Hospital unaware about the early symptoms of visual for detail ophthalmic evaluation and treatment by impairment and thus results in the high incidence of specialists. The refractive status of children was uncorrected refractive errors. 4 Visual impairment due assessed by retinoscopy under cycloplegic refraction to refractive error can be detected among the (cyclopentolate eye drops 1%). Children were population by vision screening programs. Such prescribed spectacles three days after initial surveys can best be initiated in schools, since the evaluation. Statistical analysis of the relevant data refractive errors identified at a young age can be was done by using appropriate statistical test. corrected by providing quality spectacles and thus Institutional Ethical Committee clearance was save the child from becoming visually handicapped. obtained. A health education activity (IEC) on Materials and Methods: common ocular problems was arranged for the A prospective observational study was carried out in children in the school and subsequently in the school children of rural area, to find out the hospital with the help of charts and posters. prevalence of refractive errors by vision screening Arrangements were made for free spectacles. programme. Primary screening was carried out by Results: trained teachers of the school. During two months of A total of 1220 school going children of standard 5 th , study period, 1220 students of age group 10 to 12 6th and 7 th were screened for visual acuity using years were screened to find out the refractive errors. Snellen’s charts. Out of the total 1220 children The inclusion criteria include children in the age screened, 721 were boys and 499 were girls. Total of group of 10 to 12 years as they are cooperative for 266 children had defective vision, out of which 128 vision testing and there would be better compliance (25.65%) were girls and 138 (19.14%) were boys.

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International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

Table 1: Age and gender distribution of study population screened Age Girls Boys Total 10 yrs 151 212 363(29.75%) 11 yrs 180 251 431(35.33%) 12 yrs 168 259 427(35%) Total 499(40.90%) 721(59.10%) 1220

Figure 1: Distribution of children as per visual performance

266

954

CHILDREN WITH NORMAL VISION CHILDREN WITH DEFECTIVE VISION

Figure 2: Gender distribution of children with normal and defective vision

700 Boys, 583 600 500 400 Girls, 371 300

200 Boys, 138 Girls, 128

No ofStudents No 100 0 Normal Vision Defective Vision

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International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

Figure 3: Distribution of students according to their visual acuity

120 107 100 100

80

60

40 23

NO OF STUDENTS OF NO 19 20 15 7

0 6 by 9 6 by 12 6 by 18 6 by 24 6 by 36 6 by 60

Figure 4: Comparison between myopia and hypermetropia amongst the screened population

The above bar diagram shows a predominance of myopia over hypermetropia in the screened visually defective children.

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International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

Figure 5 : Other ocular findings associated with refractive error

VITAMIN A DEFICIENCY 8

SQ UINT 11

CONGENITAL TOXOPLASMO SIS 1

IRIS COLOBO MA 1

PAPILLARY HYPERTROPHY 1

KERATOCONUS 1

AMBYLOPIA 18

NYSTAGMUS 2

MYOPIC 2

POSTERIOR STAPHYLO MA 6

0 2 4 6 8 10 12 14 16 18 20

Discussion: uncorrected visual impairment ( ≤ 6/12 in the better Blindness is defined either in terms of best-corrected eye) in the urban and rural group was found to be distance visual acuity or presenting distance visual 9.8% and 6.6% respectively, which dropped to 7.1% acuity. Level of visual acuity of less than 3/60 in the and 3.3% respectively with presenting vision, and better eye has been commonly used to define reduced to 1.1% and 2.5% respectively with best blindness. A normal eye condition whereby with no corrected visual acuity. The primary cause of the , parallel light is focussed on the visual impairment was myopia and increased retina is called emmetropia. Thus any optical incidence was observed in urban population than departure from this condition is called refractive error rural. This was attributed to increased literacy rate (RE) or ametropia. There are three kinds of refractive and more visual associated activities like use of errors namely myopia, hypermetropia and computers, watching television for longer hours. 7 In a astigmatism. 2,5 According to WHO estimates, similar type of study, by Kasa T & Allene S D, globally there are 40 million blind people and an prevalence rate of visual impairment due to refractive additional 245 million visually impaired. 1 A further error in a preschool and school children aged 5 to 15 517 million people have significant near vision years of Debark & Kola Diba towns, was found to be impairment caused by uncorrected . 6 7.6%. Myopia was a major cause of visual A comparative survey of prevalence of refractive impairment. 8 Further 5.6% of the children were error in urban and rural school children in and around observed to have a visual acuity of <6/12 in the better Hyderabad was carried out. Prevalence of eye while 2.6% showed visual acuity <6/18.

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International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

In the present study as evident from figure 1, the a previous history and current use of spectacles as a sample size of girls and boys studying in 5 th , 6 th and visual aid. This can be attributed to illiteracy amongst 7th standard were apparently not largely different. The the parents of the children. Majority of the parents of total number of children screened in 5 th , 6 th and 7 th the children earn daily wages and belonged to low standards was 29.75%, 35.33% and 35% respectively. socio-economic group. Due to low socio-economic Out of the 1220 children screened, 266 children with status of the parents they could not afford frequent <6/6 visual acuity as determined by Snellen’s chart visits to the eye care centre and the cost of the visual were identified with defective vision (21.80%). aids (e.g- spectacles). This depicts ignorance amongst Children with visual acuity of less than 6/9, 6/12, the community as a cause of increased risk of ocular 6/18, 6/24, 6/36 and 6/60 were identified and morbidity in the future. Hence a provision was made segregated from the total number of students with for free spectacles for the children with the help of a defective vision. The number of students (figure 3) non-governmental organisation. with the above visual acuity is 100,110,21,19,13 and The incidence of myopia was more than 3 respectively. hypermetropia in the screened population. Refractive The prevalence of myopia in the present study (figure errors were commonly seen in males than females. 6) is 17.13%. There was a similar study which was Correction was given to these children with conducted in western china in which the incidence of appropriate lenses. Arrangements for free spectacles myopia was found out to be 13.75%. Many studies were made with help of a non-governmental which detected refractive error in school children organisation. Health education was imparted to the have reported myopia to range from 4% to about 8%. children and counselling regarding need and In one primary school study of Qazvin city importance of regular follow-up and use of spectacles prevalence of refractive error was 61.9% of those was emphasised to the parents. 65.03% were myopic. This difference may be Conclusion: attributed to various factors such as geographical There is need for awareness among the community location, economic development, contributing about the ocular health. It can be done through mass environmental factors and the overall awareness media (electronic and paper media), through amongst the masses. Amongst the visually defective awareness campaigns, rallies, posters, exhibitions, children 78.57% comprises of myopia while the rest etc. Vision testing must be added in the schedule of is of hypermetropia. Also the incidence of child health programme implemented by government. hypermetropia amongst the total screened masses is Annual school health check-ups must focus their 4.67% in present study. Hence from the above attention towards vision impairment due to refractive findings it is clear that the incidence of myopia errors and affected children should get visual aids. amongst school going children is higher than that of Up gradation of ophthalmic facilities/services at hypermetropia. The incidence of myopia is 17.13%. primary health centers should be done so that it Hence the primary cause of visual impairment becomes easily accessible for rural population. amongst these children is myopia. Out of the total children having defective vision, only 6 children had

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International J. of Healthcare and Biomedical Research, Volume: 03, Issue: 03, April 2015, Pages 45-51

Acknowledgement: We are grateful to Pravara Rural Hospital, Loni and Indian Council of Medical Research (ICMR) for allowing us to do this study. References:

1. Resnikoff S, Pascolini D, Mariotti SP, Pokharel GP. Global magnitude of visual impairment caused by uncorrected refractive errors in 2004. Bull World Health Organ. 2008; 86: 63–70. 2. Pizzarello L, Abiose A, Ffytche T. et al. Vision 2020: the right to sight: a global initiative to eliminate avoidable blindness. Arch Ophthalmol. 2004; 122: 615-20 3. Dandona R., Dandona L. Childhood blindness in India: a population based perspective. Br. J. Ophthamol. 2003; 87: 263-65 4. Fotouhi A., Khabaz KM, Hashemi H et al. The prevalence of refractive errors among schoolchildren in Dezful, Iran. Br J Ophthalmol. 2007; 91: 287–92 5. Parr J. Introduction to Ophthalmology, Oxford Medical publications. Dunedin, New Zealand,1989; 44-45 6. Dandona R, Dandona L, Srinivas M, Sahare P, Narsaiah S, Muñoz SR, Pokharel GP, Ellwein LB (). Refractive error in children in a rural population in India. Invest Ophthalmol Vis Sci. 2002; 4: 615-22 7. Pi LH, Chen L, Liu Q, Ke N, Fang J, Zhang S, Xiao J, Ye WJ, Xiong Y, Shi H, Yin ZQ. Refractive Status and Prevalence of Refractive Errors in Suburban School-age Children. Int J Med Sci. 2010; 7: 342-53 8. Kassa T., Alene G.D. Prevalence of refractive errors in pre-school and school children of Debark and Kola Diba towns, North-western Ethiopia. Ethiop. J. Health Dev.17(2);117-24

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