Vision Impairment among Children in South India: Results from a Large-Scale School Eye Screening.

PURPOSE: To provide the prevalence of vision impairment and blindness among 250,000 school children aged 6 to 17 years, screened in Tamil Nadu, India. METHODS: The study was conducted between 2016 and 2019 as a part of the school eye screening program in Kanchipuram district, Tamil Nadu. The clinical examination included basic vision testing, objective refraction, subjective acceptance, spectacle dispensing, and a posterior segment evaluation. The prevalence of vision impairment, blindness, low vision, and the association with other demographic variables using logistic regression were calculated. RESULTS: A total of 250,052 children were screened in 1047 schools and the prevalence of vision impairment, blindness, and low vision in Kanchipuram district was 3.83%, 0.01%, 0.19%, respectively. The major causes for vision impairment, blindness, and low vision were refractive errors (3.05%), high myopia (0.002%), and refractive amblyopia (0.04%), respectively. Vision impairment was significantly associated with urban location (OR = 1.42, 95% CI 1.36-1.48, p < .0001), females (OR = 1.11, 95%CI - 1.08-1.15, p < .0001), private schools (OR = 2.43, 95%CI - 2.35-2.42, p < .0001), higher secondary class grade (OR = 1.69, 95%CI - 1.61-1.77, p = .001), high-school class grade (OR = 1.65, 95%CI - 1.58-1.72, p = .001) and middle school class grade (OR = 1.53, 95%CI - 1.47-1.59, p = .001). CONCLUSION: This large-scale school eye screening reports a comparatively lower prevalence of vision impairment, blindness, and low vision when compared to other studies conducted around the world. Although the overall prevalence is relatively low, the causes are mostly refractive. Urban, female, private school-going children aged 11-17 are at higher risk.

Distribution of Astigmatism among School Children Who Fail Vision Screening in South India.

PURPOSE: The purpose of this study is to report the distribution of astigmatism among school children in South India. METHODS: The study was conducted as part of a national school eye screening project named 'Refractive Error Among Children' (REACH) between 6 and 17 years of age. Children underwent presenting visual acuity screening, external eye examination, screening for color vision deficiency, and non-strabismic binocular vision anomalies. Those who failed screening underwent, objective and subjective refraction, and identification of other ocular conditions. Astigmatism was defined as cylindrical power greater than 0.50D. Refractive errors were classified into myopia (≤0.50D), hyperopia (≥0.75D), and other refractive errors (between -0.50D and +0.75D). The data on astigmatism were analyzed and were deduced into its vector components (M, J0 and J45). Descriptive statistics and regression analysis were performed. RESULTS: Data of 245,565 children from 1047 schools were taken for analysis. The average age was 11.63 ± 3.32 (range:6-17) years. After screening, refractive errors and astigmatism was found to be 6.57% (n = 16157) and 3.69% (n = 9064), respectively. Astigmatism among children aged 6 to 10 years was 1.37%. The mean cylindrical power, J0, and J45 was found to be 1.93 ± 1.06D, 0.06 ± 0.59D, and 0.43 ± 0.81D, respectively. Linear regression showed a decreasing trend in the cylindrical component (p < .001) and shift towards less positive J0 values (p < .001). Higher proportions of astigmatism more than 1.50 D (1.83%,n = 4578) and unilateral astigmatism (1.20%,n = 2952) are evident among refractive errors. CONCLUSION: More than 50% of children who failed vision screening with refractive errors presented with astigmatism. Prevalence was higher among primary school children. Presence of higher magnitude and unilateral astigmatism is amblyogenic and needs early intervention.

Profile of ocular conditions from school eye screening in Southern India.

Purpose: To profile the presentation of ocular conditions among school children aged 6 to 17 years from the south Indian state of Tamil Nadu. Methods: The study was conducted as part of a school eye health program in Kanchipuram district, Tamil Nadu that aimed to address the refractive needs of children (6-17 years) between July 2016 and June 2019. The study followed a three-phase protocol, which included visual acuity test, modified clinical test, color vision test, binocular vision assessment, objective and subjective refraction, dispensing spectacles, posterior segment evaluation using direct ophthalmoscopy, and referral to the base hospital. The demographics, clinical details, and ocular conditions (classified under 16 categories) were analyzed. Profiling and association of ocular conditions among different locations, types of schools, class grades, and gender were presented. Results: Data of 2,45,565 children were analyzed from 1,047 schools, of which 4,816 (1.96%) children were identified with ocular conditions other than refractive errors. The common reasons for referral were high myopia 901 (0.37%), strabismus 819 (0.33%), and amblyopia 691 (0.28%). Retinal problems (odds ratio [OR]: 1.65, 95% confidence interval [CI]: 1.22-2.22, P = 0.001) and strabismus (OR: 1.41, 95% CI: 1.21-1.65, P < 0.001) were the conditions prevalent in the rural location. Cataract and related conditions (OR: 5.73, 95% CI: 4.10-8.01, P < 0.001) and retinal problems (OR: 4.76, 95% CI: 3.37-6.72, P < 0.001) were common in children studying in public schools. Of the 16 categories, 13 conditions were seen among primary school children. Vernal keratoconjunctivitis (OR: 3.64 95% CI: 2.12-6.23 P < 0.001) was common among males. Conclusion: The study profiled ocular conditions among school children. Most ocular conditions warrant prolonged care and specialty eye care services. Ensuring the availability of such services and follow-up after school eye screening would safeguard the visual development of these children.

Prevalence of color vision deficiency among school-going boys in South India.

Purpose: Impact of color vision deficiency (CVD) on activities at school and productivity at work and consequential psychosocial difficulties has been reported. Although early detection and awareness help in overcoming these difficulties, screening for CVD is not a part of the school eye-screening initiatives in many countries. This study aimed at reporting the prevalence of CVD among school-going boys in Kanchipuram district, South India. Methods: The study was carried out as part of a school eye-screening program (SES) conducted in Kanchipuram district, Tamil Nadu, India for children between 6 and 17 years. The SES followed a three-phased protocol, which also included screening for CVD for all the boys between 11 and 17 years. The boys underwent CVD screening with Dalton's pseudo isochromatic plates (PIPs) followed by confirmation with Ishihara's PIP. The data were analyzed and the proportion of CVD in boys among different class grades, type of schools, location of schools, blocks of the district, and other clinical characteristics are presented. Results: Totally 250,052 children were screened in 1047 schools of which 74986 (60.61%) were boys between 11 and 17 years (mean age: 13.75 ± 1.91). The overall prevalence of CVD was found to be 2.76% (n = 2073; 95% confidence interval [CI]: 2.65-2.88). CVD was associated with urban locations (3.17% odds ratio [OR]: 1.90 95%CI: 1.69-2.13 P < 0.05) and public schooling (2.87%) (OR: 1.29 95%CI: 1.17-1.43 P < 0.05). Boys with CVD were less likely to have vision impairment (P = 0.002) and myopia (P < 0.001) as compared with boys with normal color vision. There was no significant difference in the proportion of other ocular conditions between children with and without CVD (P > 0.05). Conclusion: The study shows a significant proportion of CVD among boys in Kanchipuram district, India and its association with various demographic and clinical characteristics. Identification of CVD and counseling the stakeholders earlier through school children screening is crucial.