Prevalence Of Refractive Errors In School Going Children In Rural And Urban Areas -A Cross-Sectional Study

Prevalence Of Refractive Errors In School Going Children In Rural And Urban Areas -A Cross-Sectional Study Triveni C.1, Divya T.2*, Rama Devi P.3, Chowdary N.4, Sirisha G.5 DOI: https://doi.org/10.17511/jooo.2021.i02.01 1 Chimata Triveni, M.S, Associate Professor, Department of Ophthalmology, NRI Academy of Medical Science, Guntur, Andhra Pradesh, India. 2* Tirumuru Divya, M.S, Assistant Professor, Department of Ophthalmology, NRI Academy of Medical Science, Guntur, Andhra Pradesh, India. 3 Ponna Rama Devi, M.B.B.S, Postgraduate, Department of Ophthalmology, NRI Academy of Medical Science, Guntur, Andhra Pradesh, India. 4 N. Lakshmi Chowdary, M.S, Professor, Department of Ophthalmology, NRI Academy of Medical Science, Guntur, Andhra Pradesh, India. 5 Gantela Sirisha, M.S, Professor, Department of Ophthalmology, NRI Academy of Medical Science, Guntur, Andhra Pradesh, India.


Introduction
Ametropia or refractive error is the term for any refractive condition other than emmetropia or condition in which parallel rays of light fail to converge to a sharp focus on the retina with accommodation at rest. Refractive error includes myopia, hyperopia, and astigmatism. In 1994, the National program for control of blindness initiated a school eye screening program.

Objective
The objective of this study is to determine the association between demographic character and refractive errors with rural and urban school children of 5-15 years of age.

Study population and Study site:
The study population included all the children of the age group 5-15 years, studying in rural and urban schools. The children were examined in the classrooms of the schools. A pilot study was performed to assess the interexaminer reliability of two optometrists, which was found to be high (0.923). These two optometrists conducted all the examinations in schools and referred students to the hospital.

Refractive Error Examinations:
The examination conducted involved three main steps: The first step was examination of visual acuity using the Snellen chart.
All the children with vision less than 6/6 were subjected to autorefractrometry using a portable autorefractometer, and all of them were given a full correction.
Those children whose vision was not improving with refraction were referred to the ophthalmology outpatient department at NRI Medical College and General Hospital, Chinakakani. For those who were referred to OPD, the complete ophthalmic examination was done with a slit lamp to rule out any anterior segment abnormalities.
After slit-lamp examination, children were subjected to cycloplegic refraction using 0.5% cyclopentolate eyedrops, and streak retinoscopy was done. Fundus examination was done with slit-lamp biomicroscopy.
Children were asked to come after two days for a post mydriatic test, and spectacles were prescribed.
Types of refractive errors were identified and recorded for analysis.

Results
The prevalence of refractive error was found to be 6.41 %, with a prevalence of 7.61% in urban and 5.21% in rural areas.    showed a similar pattern, but a slightly higher prevalence was noted. The majority of the participants were in the age group 13 to 15 years, 47.37% in the urban area and 61.54% in the rural area, followed by the age group 9-12 years, in this study. Similarly, many studies reported an increase in the prevalence of refractive error with increasing age. [13,14,15] In contrast, Khandekar et al.
reported that refractory error was more in the age group 9-12 years, followed by 6-8 years. [11] In the present study, refractive errors were seen more in males, 52.63% from the urban area and 73.08% from the rural area. In a study by Khandekar et al., boys had the higher uncorrected refractive error, although gender was not significantly associated with uncorrected refractive error in urban and rural children. [11] In contrast, studies by Vidusha KSS et al. [15] Prema N et al. [16], and Yadav et al. [17] reported female preponderance for refractive errors in their study.

Triveni C. et al: Prevalence Of Refractive Errors In School Going
Tropical Journal of Ophthalmology and Otolaryngology 2021;6(2) The main type of uncorrected refractive error was myopia in this study, which was significantly higher in urban children compared to rural children (73.68% in the urban area and 69.23% in the rural area). Studies by Dandona et al. [18] and Khandekar et al. [11] found the prevalence of myopia to be 5%, 2.5%, 3.16%, 1.45% in urban and rural regions, respectively. Many studies reported myopia as the most common pathology among refractive errors. [15], [19] Dandona et al. [18] in Andhra Pradesh eye diseases study also noted that urban location was a predictor of myopia, and children of the urban area had 2.5 times higher risk compared to rural children. Increased prevalence of myopia in an urban population may be due to increased literacy rate, educational demands, and differences in lifestyle, for example, reading, watching TV, and computer visual display units. [20] The prevalence of refractive error was significantly associated with the duration of using the computer in this study. Kumar P et al. and Sharma S et al. reported that refractive error was more common in the students who have a history of watching TV/or computer for more than 3 hours. [21.22] Rathod HK et al. [13] also reported that defective eye problem was more in that students who had a history of watching TV. The presence of refractive error was significantly associated with a positive family history, as seen in other studies. [23,24,25] Periodic eye check-ups are essential for school children and should be included in the school health screening programs, as early detection helps in the prevention of complete blindness and ocular infections. Parents and teachers should be educated about the importance of eye care and taught not to ignore any complaint of the child. [20] Limitation The data was collected through a self-reported questionnaire to the parents; hence, there is a potential of recall bias. The questionnaire on risk factors was given only to the students who were having refractive errors. The sample was restricted to a narrow age group, even though refractive errors are common in 5 to 15 years of age.

Conclusion
The prevalence of refractive errors was more in urban school children than in rural. Refractive error was more prevalent in the 13-15 years age group, in both rural and urban school children.
The common refractive error was found to be myopia, followed by astigmatism and hyperopia.

What does the study add to existing knowledge
There is a dearth of data on refractive errors between rural and urban students in the Guntur district of Andhra Pradesh. Tropical Journal of Ophthalmology and Otolaryngology 2021;6(2)