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 Table of Contents  
Year : 2021  |  Volume : 1  |  Issue : 1  |  Page : 26-31

Mohsin's schoolchildren eye screening program - Analysis of the results

1 Department of Community Ophthalmology, Visakha Eye Hospital, Visakhapatnam, Andhra Pradesh, India
2 Department of Community Ophthalmology, Visakha Eye Bank Research and Training Trust, Visakhapatnam, Andhra Pradesh, India

Date of Submission22-Jul-2021
Date of Decision01-Oct-2021
Date of Acceptance04-Oct-2021
Date of Web Publication01-Nov-2021

Correspondence Address:
Dr. Pandiri Venkatagiri Syamala
Visakha Eye Hospital, Pedda Waltair, Visakhapatnam - 530 017, Andhra Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jocr.jocr_17_21

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Aim of the Study: To determine the prevalence of ocular morbidity among government schoolchildren from Mohsin's Schoolchildren Eye Screening Program. Design: A school-based, observational study design. Participants: Schoolchildren between 1st and 10th standards across various government schools. Materials and Methods: Students of 429 government schools of Visakhapatnam were covered under this eye screening program. It was a three-staged program. In the first stage, 84,727 students were screened for visual impairment and the presence of any abnormality by trained teachers or optometrists. In the second stage, those who were identified were subjected to a detailed ocular examination and refraction in the school premises by trained optometrists. Glasses were dispensed for those who improved to normal visual acuity and treatment was given for minor ailments by optometrists, residents and ophthalmologists requiring further evaluation were referred to the base hospital for examination and appropriate management by an ophthalmologist in the third stage. Results: 84,727 children from 429 schools were screened. Ocular morbidity was 6.07%. Refractive error was the most common ocular disorder identified in 3.74% with a significantly high rate among secondary schoolchildren (P < 0.001). Other common abnormalities found were color blindness (1.25%), allergic conjunctivitis (0.12%), squint (0.08%), infective conjunctivitis (0.02%), amblyopia (0.02%), and lid and adnexal disorders (0.02%). Conclusion: Ocular morbidity is a significant problem among schoolchildren. Visual impairment due to refractive errors is common and can be corrected by prescribing glasses. School screening programs are effective and essential in identifying ocular morbidity in schoolchildren.

Keywords: Childhood visual impairment, ocular morbidity, refractive errors, school eye screening

How to cite this article:
Syamala PV, Raju RS, Raju C V, Ahikrishna R, Chetty A V. Mohsin's schoolchildren eye screening program - Analysis of the results. J Ophthalmol Clin Res 2021;1:26-31

How to cite this URL:
Syamala PV, Raju RS, Raju C V, Ahikrishna R, Chetty A V. Mohsin's schoolchildren eye screening program - Analysis of the results. J Ophthalmol Clin Res [serial online] 2021 [cited 2023 Sep 23];1:26-31. Available from: http://www.jocr.in/text.asp?2021/1/1/26/329771

  Introduction Top

Good vision is essential for the psychosocial development of children.[1] According to population-based studies in India, the prevalence of ocular morbidity in children ranged between 1.3% and 6.54%.[2],[3],[4] Data from school-based studies show a prevalence of 13%–45%.[5],[6],[7],[8] The World Health Organization estimates that 13 million children aged 5–15 years worldwide are visually impaired from uncorrected refractive error (URE).[9] In India, the prevalence of visual impairment among children varied between 2.05 per thousand and 13.6 per thousand.[4],[10],[11] Refractive error was the main cause of moderate visual impairment in children and a public health problem as seen in a study conducted in South India.[2]

Apart from refractive errors, various other ocular morbidities such as squint, color blindness, and Vitamin A deficiency, have been variably reported in schoolchildren across the literature.[5],[6],[12],[13] A wide range of abnormalities such as convergence insufficiency, allergic conjunctivitis, viral conjunctivitis, whole globe abnormalities, corneal opacities, ptosis, retinal, and neuro ophthalmological causes have been reported by various studies.[6],[13],[14] Any such abnormality is capable of causing visual impairment or discomfort, leading to an interference with the learning as well as significant loss of days of attendance from the school.

School-based eye screening programs are more effective than other primary eye care models in delivering eye care to school-going children.[15] There are established school screening programs from the National Program for Control of Blindness and Visual Impairment to identify visual impairment in children.[16] To supplement the above programs, many Non-Governmental Voluntary Organizations (NGO) conduct schoolchildren eye screening programs.[17] The purpose of this program was to screen children studying in Municipal corporation schools for ocular morbidity. This study aimed to determine the prevalence and causes of ocular morbidity among children from Municipal Corporation Schools of Visakhapatnam, based on data from school eye screening from the above program. To the best of our knowledge, there is no data on the prevalence and causes of ocular morbidity among municipal schoolchildren in this region.

  Materials and Methods Top

This study was based on the data obtained from the school screening program described below. Mohsin's Schoolchildren Eye Screening Program was established by two NGOs. Children aged 6–15 years, enrolled in the municipal corporation schools of Visakhapatnam, from 1st to 10th standards were included. Institutional Ethics Committee approval was obtained and the study was conducted in full accord with the tenets of the Declaration of Helsinki. These schools were chosen because the majority of the children in them are from low-income groups where awareness is minimal and accessibility and affordability to eye care are barriers.[18] After taking written permission from the municipal authorities, the principals of the schools were informed and appropriate permission was taken. The school management informed the parents regarding the study and informed consent was taken through school diaries. Then, these children were screened through this program from April 2019 to March 2020. The process was planned in three stages. Before the first stage, volunteers who were nonoptometrist staff from a tertiary eye care center and an NGO and teachers were trained regarding the identification of ocular disorders. They were provided with demonstrations of vision screening using Snellen's charts and gross ocular examination to detect a deviated eye (squint), lusterless eyes or Bitot's spot, white opacity (corneal or lenticular), and signs of ocular allergy, etc., using teaching modules. An ophthalmologist undertook the training of the teachers and volunteers using the modules. Following this, a screening was by the optometrists, teachers, and volunteers, which constituted the first stage of the program. For all the students, vision screening was performed using Snellen's charts at six meters distance in outdoor illumination. Color vision was examined using an Ishihara's chart. Ocular examination was performed using a torchlight.

In the second stage, students with a visual acuity of >6/12 or any abnormal ocular findings were sent for a detailed examination by the optometrists, residents, and ophthalmologists within the school premises on the same day.[19] They carried out ocular examination including fundus examination, cycloplegic refraction with cyclopentolate 0. 5% eye drops in selected cases, either in the mobile unit or in a makeshift room in the school equipped with an auto refractometer, streak retinoscope, a slit lamp, and ophthalmoscope.

Operational definitions

Ocular morbidity was defined as an abnormality in any of the ocular structures, which may or may not be visually significant and which may or may not require/improve with treatment.[20] Myopia was diagnosed if spherical equivalent (SE) refraction was<–0.50 diopter sphere (DS). Hyperopia was diagnosed if SE was ≥±1.00 DS and astigmatism if cylindrical power was ≥±0.75 diopter cylinder (DC) in either eye.[21] A child was considered myopic or hyperopic if at least one eye was defective. Other ocular conditions were diagnosed based on standard diagnostic criteria. Children with refractive errors were prescribed appropriate glasses and the spectacles were dispensed in the schools. Those with ocular abnormalities which could be managed at the field level were treated with medication where possible. Other cases where the further examination was necessary were referred to the base hospital. In the third stage, children who reported to the base hospital underwent an examination by an ophthalmologist and appropriate management was advised. The children who were diagnosed to have refractive errors and amblyopia were prescribed glasses with amblyopia therapy in the form of occlusion therapy. Those with allergic conjunctivitis were prescribed antihistamine drops. Those with lid problems such as hordeolum and blepharitis were prescribed topical antibiotics. Those with cataracts and squints were advised surgery where necessary. This was done by an ophthalmologist at the base hospital.

Data were entered in preexisting formats in MS Excel and analyzed in Statistical Product and Service Solutions, version, 24, IBM corporation, Armonk, New York, USA, 2016. Descriptive statistics were represented with frequencies and percentages. 95% confidence intervals (CI) were calculated. A Chi-square test was applied. P < 0.05 was considered statistically significant. The children were divided into primary school (1st–5th standards), upper primary school (6th and 7th standards), and secondary school (8th, 9th, and 10th) students based on the class in which they studied.

  Results Top

Under the municipal corporation of Visakhapatnam, there were 429 government schools. A total of 98,623 children were enrolled in these municipal corporation schools. 84,727 (85.9%) of these were screened. The remaining numbers were lost to screening due to their absence from their respective schools during the time of the screening. The three-tier system of screening adopted and the numbers identified at each stage, in brief, are shown below in [Figure 1]. The mean age of the students was 10.5 years with a standard deviation of 2.32 years (range: 6–15 years, mean 10.5 ± 2.32). 43,206 (50.9%) of them were female and 41,521 (49%) were male. A total of 6106 students were identified with ocular abnormalities in the first stage. Among these, the total number of ocular morbidities identified after the final optometrist evaluation (the second stage) in the school premises was 5146 (6.07%). Refractive error was the most common ocular disorder identified in 3165 (3.73%) cases. It was more common in secondary schoolchildren (P < 0.001with 95% CI), but there was no association with gender. Among these, 1064 students (1.25%) were already wearing glasses, whereas 2101 (2.47%) of students were newly diagnosed with refractive errors and were provided with spectacles. The prevalence of refractive error in each school group was as shown in the table below [Table 1]. The most common type of refractive error was myopia (2.16%). Myopia also was more common in secondary schoolchildren (P < 0.001 with 95% CI) but there was no association with gender. The prevalence of the other refractive errors was astigmatism – 1.43% and hyperopia – 0.12%. The power-wise distribution among each school group is shown in [Table 2]. In the second stage, 113 cases with other ocular morbidities were treated within the school premises by the optometrists, residents, and ophthalmologists, by administering necessary topical medications. They included allergic conjunctivitis (87), infective bacterial/viral conjunctivitis (21), hordeolum (3), and dry eyes (2).
Figure 1: Flow chart showing the three-staged screening procedure adopted and numbers identified at each stage

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Table 1: Distribution of refractive errors in each class group

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Table 2: Distribution of refractive errors in each class group based on the magnitude of power and type of error

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1868 (2.2%) students were identified for base hospital referral. Among these, only 1223 (65.4%) reported for further examination. The spectrum of the total ocular morbidities, i.e., those treated in the second stage (apart from refractive errors) as well as those who reported to the base hospital is shown below in [Figure 2]. The various ocular morbidities diagnosed in stage three have been listed below in [Table 3]. The number of false positives from the first stage was 960. The false positivity rate for screening in the first stage was 1.19%.
Figure 2: Spectrum of ocular morbidity other than refractive errors

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Table 3: Various ocular morbidities identified in Stage 3

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  Discussion Top

The prevalence of ocular morbidity diagnosed through this school screening program in Visakhapatnam was 6.07%. This prevalence rate is similar to the rate of ocular morbidity found by Kemmanu et al. in the Pavagada Pediatric Eye Disease Study 2.[14] This study also was conducted in the Southern part of the country. The ocular morbidity reported from previous studies was higher when compared to our study.[3],[5],[6],[13]This could probably be attributable to the racial and geographic differences.[22] Refractive error was the most common cause identified in 3.74%. This prevalence was significantly higher in the secondary school group (P < 0.001). There was no association with gender. The most common type of refractive error was myopia (2.16%). Again, it was more common in secondary schoolchildren (P < 0.001) but there was no association with gender. Multiple other studies conducted in our country stated similar results that the most common error was myopia.[19],[21],[23],[24],[25],[26] However, in a study from Manipur, the most common refractive error found was astigmatism.[3] This again could be attributable to the racial differences.[27] There was a statistically significant association with the high school group implying an association with higher ages. It is known that this is due to the growth spurt that occurs at this age. This is in accordance with previous literature.[2],[6],[13] However, we did not find any association with gender. Bigyabati et al. found a correlation between female gender and refractive error.[3] Possible female preponderance in their study could be due to the differences in the cultural and social behavioral patterns in the rural areas. Our population was an urban population and all cases belonged to a predominantly low-income group. The prevalence of URE in our study was 2.49%. This was much lower than the rates found by Padhye et al. in a study conducted by them in Maharashtra, where they reported a rate of 5.46% in the urban population and 2.63% in the rural population.[28] Our population could have possibly been an urban population who migrated from rural areas. This could explain the lower prevalence when compared to other studies stating higher prevalence among urban populations. The number of students with UREs of more than 2D magnitude was 359. Such a high degree of refractive error indicates that this would have been long-standing and has been diagnosed only during a school screening.[29] These could perhaps reflect poor awareness among parents and hence the necessity for screening, especially in government schools. These programs are particularly useful in children who do not complain of defective vision or are usually too young to notice any difference in their acuity. They might compensate by squeezing their eyes, sitting close to the blackboards or by noting down from a classmate. Some might presume that others have the same visual acuity as theirs. The rate of newly diagnosed refractive errors was much higher than the existing ones highlighting the need for an effective screening strategy. The rates of myopia (2.16%), astigmatism (1.43%), and hyperopia (0.12%) were similar to a study conducted in Maharashtra by Padhye et al.[28] Agarwal et al. found Vitamin A deficiency to be the most common cause of morbidity in their study from Central India in contrast to the present study where the refractive error was the most common cause. However, they included the rural population as well.[13]

Among the other disorders, color blindness (1.2%), allergic conjunctivitis (0.12%), and strabismus (0.08%) were the most common. Similarly, Gupta et al. found squint (2.5%) and color blindness (2.3%) to be more common after refractive errors.[5] However, their rates were higher. Agarwal et al. reported a prevalence of 0.2% in the urban population for squint.[13] Bigyabati et al. reported 0.1% prevalence for squint.[3] Dandona et al. found cataracts to be more common after refractive errors with a prevalence rate of 2.16% and 3.65% in urban and rural areas, respectively.[2] This was a population-based study. We found a prevalence rate of 0.009% for cataracts. Amblyopia was seen in 0.02% of the cases and the most common cause was anisometropic hyperopia. This is similar to the 0.08% reported in the urban population by Dandona et al.[2] Higher rates were reported by Agarwal et al.(0.4%) and Gonsalves et al. (0.37%).[13],[19] The prevalence of Vitamin A deficiency in this program was only 0.002%; this was much lesser than that found by previous studies. This could be because ours was predominantly an urban population and this improves the accessibility to programs with Vitamin A supplementation. The prevalence of these ocular morbidities was not analyzed according to the class group or gender because of the small sample size in each group. We had analyzed only visual impairment in this study but not blindness.

Among the 1868 cases referred, only 1223 (65.4%) came for an examination in the hospital. This could be due to the low awareness and the economic constraints among the parents who usually belong to the low socioeconomic groups. There is a necessity to implement appropriate strategies to improve the reporting to the base hospitals. These could include the prior spread of awareness regarding the importance of such ocular ill health and the involvement of the teachers and the principals of schools in seeing that the referred students reach the base hospital by close follow-up and repeated motivation.

The false positivity rate of screening in the first stage was 1.19%. The positive predictive value of school vision screening by teachers, volunteers and optometrists in the first stage was 81.30%. In a study by Gurvinder et al., the positive predictive value was only 47.25%.[12] Shukla et al. reported a positive predictive value of 68.9% in their study.[25] The high value in our study could be due to the involvement of trained optometrists along with teachers as compared to the above studies where only teachers were involved. The false-positive rate could also signify that some students were unfamiliar with the standard screening procedures and had not performed correctly in the first stage. A repeat examination could have made them more accustomed to the procedure and they could have possibly performed better. A false-positive rate is always better than a false-negative rate as it only increases the chance of diagnosing a disorder by re-examination by a trained optometrist.

Furthermore, as many as 1061 cases with color blindness were picked (1.25%). The prevalence of color blindness in various other studies was 2.3% (Gupta et al. from Shimla), 3.3% (Agarwal et al. from Madhya Pradesh), 0.98% (Gonsalves et al. from Karnataka), and 0.02% (Mallireddy et al. from Andhra Pradesh).[5],[13],[19],[30] Most people realize that this defect only after a routine medical test is done before recruitment into a service or a job. Diagnosing these disorders early during childhood would help the children and the family plan the professions accordingly. Hence, the authors recommend that color vision screening also should be included in school screening programs.

The strength of this study is its large sample size, high coverage of the population of up to 86%, and the three-tier system of examination adopted. Free spectacles were provided in the field which could provide further motivation for these families to attend such programs in future. This system could be a very efficient model in picking up ocular disorders given the extensive coverage and the pick-up rate, especially in a scenario wherein trained manpower and the utility of health infrastructure by the public are low. The limitations of this study were that students who were absent during the screening were missed. This could be addressed by planning a future program to cover these students. The analysis of other ocular morbidities based on the class group or gender was not made due to the small sample size. Furthermore, more than 30% of the patients referred to the base hospital did not turn up. Hence, the cause of the morbidity could not be analyzed in these cases. Negative screening done by the teachers in the first stage was not confirmed by the optometrists. There could have been a certain number of false negatives which could have been missed.

  Conclusion Top

To conclude, ocular morbidity is a significant problem among schoolchildren. Refractive errors were the most common cause identified and could easily be treated by dispensing glasses by our NGO teams at the school premises. UREs can cause amblyopia and permanent visual impairment. These errors can be corrected if detected early. Such school screening programs are indispensable for their detection as large numbers of children can be screened easily with the help of trained personnel, including teachers. These children probably would not have been brought by their parents to the hospital for an ocular examination by themselves. These would also help policymakers to design such programs in the future so that avoidable visual impairment in children is minimized. Strategies to improve the rate of reporting to the base hospital need to be implemented.

Financial support and sponsorship

This study was financially supported by VEHT (Visakha Eye Hospital Trust) and VEBART (Visakha Eye Bank Research and Training Trust).

Conflicts of interest

There are no conflicts of interest.

  References Top

Rahi J, Gilbert C. Epidemiology and world-wide impact of visual impairment in children. In: Lambert SR, Lyons C, editors. Taylor and Hoyt's Pediatric Ophthalmology and Strabismus. 5th ed. London: Elsevier; 2016.  Back to cited text no. 1
Dandona R, Dandona L, Srinivas M, Giridhar P, Prasad MN, Vilas K, et al. Moderate visual impairment in India: The Andhra Pradesh eye disease study. Br J Ophthalmol 2002;86:373-7.  Back to cited text no. 2
Bigyabati R, Victor R, Rajkumari B. A study of the prevalence of ocular morbidities in school going children in a rural district of Manipur. J Evol Med Dent Sci 2016;5:3540-3.  Back to cited text no. 3
Kemmanu V, Hegde K, Giliyar SK, Shetty BK, Kumaramanickavel G, McCarty CA. Prevalence of childhood blindness and ocular morbidity in a rural pediatric population in southern India: The pavagada pediatric eye disease study-1. Ophthalmic Epidemiol 2016;23:185-92.  Back to cited text no. 4
Gupta M, Gupta BP, Chauhan A, Bhardwaj A. Ocular morbidity prevalence among school children in Shimla, Himachal, North India. Indian J Ophthalmol 2009;57:133-8.  Back to cited text no. 5
[PUBMED]  [Full text]  
Singh V, Malik KPS, Malik VK, Jain K. Prevalence of ocular morbidity in school going children in West Uttar Pradesh. Indian J Ophthalmol 2017;65:500-8.  Back to cited text no. 6
[PUBMED]  [Full text]  
Kumar P, Pore P, Dixit AK, Jha AK, Ahmad A, Chauhan N. Demographic profile of ocular morbidity in school children in India. Sch J App Med Sci 2013;1:645-52.  Back to cited text no. 7
Naik R, Gandhi DJ, Shah N. Prevalence of ocular morbidity among school going children (6-15 years). Sch J App Med Sci 2013;1:848-51.  Back to cited text no. 8
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.  Back to cited text no. 9
Dandona L, Williams JD, Williams BC, Rao GN. Population-based assessment of childhood blindness in southern India. Arch Ophthalmol 1998;116:545-6.  Back to cited text no. 10
Titiyal JS, Pal N, Murthy GV, Gupta SK, Tandon R, Vajpayee RB, et al. Causes and temporal trends of blindness and severe visual impairment in children in schools for the blind in North India. Br J Ophthalmol 2003;87:941-5.  Back to cited text no. 11
Kaur G, Koshy J, Thomas S, Kapoor H, Zachariah JG, Bedi S. Vision screening of school children by teachers as a community based strategy to address the challenges of childhood blindness. J Clin Diagn Res 2016;10:C09-14.  Back to cited text no. 12
Agrawal D, Sahu A, Agrawal D. Prevalence of ocular morbidities among school children in Raipur district, India. Indian J Ophthalmol 2020;68:340-4.  Back to cited text no. 13
[PUBMED]  [Full text]  
Kemmanu V, Giliyar SK, Shetty BK, Singh AK, Kumaramanickavel G, McCarty CA. Emerging trends in childhood blindness and ocular morbidity in India: The Pavagada pediatric eye disease study 2. Eye (Lond) 2018;32:1590-8.  Back to cited text no. 14
Lester BA. Comparing the cost-effectiveness of school eye screening versus a primary eye care model to provide refractive error services for children in India. Community Eye Health 2007;20:15.  Back to cited text no. 15
Jose R, Sachdeva S. School eye screening and the National Program for Control of Blindness. Indian Pediatr 2009;46:205-8.  Back to cited text no. 16
Dandona R, Dandona L. Childhood blindness in India: A population based perspective. Br J Ophthalmol 2003;87:263-5.  Back to cited text no. 17
Devi P, Srigiri S. Morbidity profile of children [6-11 years] attending municipal corporation primary schools in Visakhapatnam city, Andhra Pradesh. IOSR J Dent Med Sci 2015;14:118-22.  Back to cited text no. 18
Gonsalves S, Ganagi S, Vivedkanad U. School screening in coastal Karnataka. Rom J Ophthalmol 2019;63:245-8.  Back to cited text no. 19
Mahesh KM, John D, Rose A, Paul P. Prevalence of ocular morbidity among tribal children in Jawadhi Hills, southern India: A cross-sectional study. Indian J Ophthalmol 2019;67:386-90.  Back to cited text no. 20
[PUBMED]  [Full text]  
Krishnan VM, Baba, Poovitha R, Kumar PS. Study of prevalence of refractive errors in school children of Villupuram and Puducherry. Sch J App Med Sci 2015;3:2568-73.  Back to cited text no. 21
Rudnicka AR, Kapetanakis VV, Wathern AK, Logan NS, Gilmartin B, Whincup PH, et al. Global variations and time trends in the prevalence of childhood myopia, a systematic review and quantitative meta-analysis: Implications for aetiology and early prevention. Br J Ophthalmol 2016;100:882-90.  Back to cited text no. 22
Narayanan A, Krishnamurthy SS, Kumar R K. Status of eye health among school children in south India – Sankara Nethralaya school children eye examination study (SN-SEES). Ophthalmic Epidemiol 2021;28:349-58.  Back to cited text no. 23
Panda L, Nayak S, Khanna RC, Das T. Tribal Odisha eye disease study (TOES) # 7. Prevalence of refractive error in children in tribal Odisha (India) school screening. Indian J Ophthalmol 2020;68:1596-9.  Back to cited text no. 24
[PUBMED]  [Full text]  
Shukla P, Vashist P, Singh SS, Gupta V, Gupta N, Wadhwani M, et al. Assessing the inclusion of primary school children in vision screening for refractive error program of India. Indian J Ophthalmol 2018;66:935-9.  Back to cited text no. 25
[PUBMED]  [Full text]  
Warkad VU, Panda L, Behera P, Das T, Mohanta BC, Khanna R. The Tribal Odisha eye disease study (TOES) 1: Prevalence and causes of visual impairment among tribal children in an urban school in Eastern India. J AAPOS 2018;22:145.e1-6.  Back to cited text no. 26
Kleinstein RN, Jones LA, Hullett S, Kwon S, Lee RJ, Friedman NE, et al. Refractive error and ethnicity in children. Arch Ophthalmol 2003;121:1141-7.  Back to cited text no. 27
Padhye AS, Khandekar R, Dharmadhikari S, Dole K, Gogate P, Deshpande M. Prevalence of uncorrected refractive error and other eye problems among urban and rural school children. Middle East Afr J Ophthalmol 2009;16:69-74.  Back to cited text no. 28
[PUBMED]  [Full text]  
Verkicharla PK, Kammari P, Das AV. Myopia progression varies with age and severity of myopia. PLoS One 2020;15:e0241759.  Back to cited text no. 29
Mallireddy S, Patra R. Prevalence of refractive errors and other ocular disorders in school going children of Srikakulam district Andhra Pradesh. J Evol Med Dent Sci 2015;4:9168-72.  Back to cited text no. 30


  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3]


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