Search

Background: Success of a school vision screening program depends on compliance with the advice that is offered to the children. This study evaluates the effect of an intervention package on compliance to spectacle wear and referral in a school vision screening program.Methods: Among 8,442 children aged 13-17 years in 11 government schools in and around Chennai, India, 114 (2.2 per cent) children who required spectacles were allocated to the control arm (5,116 children) and 124 (3.7 per cent) children to the intervention arm (3,326 children). There were 44 (0.9 per cent) children in the control arm and 49 (1.5 per cent) children in the intervention arm who required referral for further management. Control schools received a conventional school screening protocol and intervention schools received 23-step interventions. Spectacle wear was noted in an unannounced direct observation after one, four and 12 months. Compliance to referral was noted based on the response of children with confirmation from medical records.Results: Spectacle compliance was significantly higher for the intervention arm compared to the control arm based on direct observation in the first month (17.6 per cent versus 49 per cent, adjusted odds ratio [OR] = 4.4, 95 per cent confidence interval [CI] 2.3-8.5, p < 0.05); in the fourth month (23 per cent versus 56 per cent, OR = 4.2, 95 per cent CI 2.3-7.8, p < 0.05); and in the 12th month (13.3 per cent versus 38.8 per cent, OR = 4.1, 95 per cent CI 1.8-9.4, p < 0.05). Referral compliance was significantly higher in the intervention arm in the first month (17.5 per cent versus 70.5 per cent, OR = 10.9, 95 per cent CI 3.8-30.9, p < 0.001) and in the fourth month (31.7 per cent versus 75.6 per cent, OR = 6.2, 95 per cent CI 2.3-16.0, p < 0.001).Conclusion: A 23-step package of interventions was effective in improving compliance to spectacle wear and referral among adolescents in a school vision screening program. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to report the minimum test battery needed to screen non-strabismic binocular vision anomalies (NSBVAs) in a community set-up. When large numbers are to be screened we aim to identify the most useful test battery when there is no opportunity for a more comprehensive and time-consuming clinical examination.Methods: The prevalence estimates and normative data for binocular vision parameters were estimated from the Binocular Vision Anomalies and Normative Data (BAND) study, following which cut-off estimates and receiver operating characteristic curves to identify the minimum test battery have been plotted. In the receiver operating characteristic phase of the study, children between nine and 17 years of age were screened in two schools in the rural arm using the minimum test battery, and the prevalence estimates with the minimum test battery were found.Results: Receiver operating characteristic analyses revealed that near point of convergence with penlight and red filter (> 7.5 cm), monocular accommodative facility (< 10 cycles per minute), and the difference between near and distance phoria (> 1.25 prism dioptres) were significant factors with cut-off values for best sensitivity and specificity. This minimum test battery was applied to a cohort of 305 children. The mean (standard deviation) age of the subjects was 12.7 (two) years with 121 males and 184 females. Using the minimum battery of tests obtained through the receiver operating characteristic analyses, the prevalence of NSBVAs was found to be 26 per cent. Near point of convergence with penlight and red filter > 10 cm was found to have the highest sensitivity (80 per cent) and specificity (73 per cent) for the diagnosis of convergence insufficiency. For the diagnosis of accommodative infacility, monocular accommodative facility with a cut-off of less than seven cycles per minute was the best predictor for screening (92 per cent sensitivity and 90 per cent specificity).Conclusion: The minimum test battery of near point of convergence with penlight and red filter, difference between distance and near phoria, and monocular accommodative facility yield good sensitivity and specificity for diagnosis of NSBVAs in a community set-up. [ABSTRACT FROM AUTHOR]

Background: To determine the spectacle reassessment rates of dissatisfied patients returning to the optical services department of a tertiary eye centre in India over a period of six years.Methods: A total of 169,567 spectacles were dispensed from the optical services department between January 2010 and December 2015. The spectacle reassessment forms of dissatisfied patients who returned to the optical services department with their spectacles were analysed.Results: A total of 797 spectacle reassessment forms were analysed. The overall spectacle reassessment rate during the study period was found to be 0.5% (95% CI: 0.467-0.472). The mean age of patients returning back for spectacle reassessment was 48 years (SD 19.9, range 3-97 years). Error in refractive correction measurement was found to be the most common reason for spectacle reassessment (54.7%), followed by dispensing error (21.1%), documentation errors while writing the prescription from the medical records in the tertiary eye care centre (12.7%), transcription error occurring at the optical services department (10.8%) and ocular pathologies (0.8%). No statistically significant difference was observed in the year-wise spectacle reassessment rates during the study period (p = 0.14).Conclusions: The frequency of spectacle reassessment rate in a tertiary eye care centre was low, with errors in measuring refractive errors contributing the most to the reassessment and reorder of spectacles. [ABSTRACT FROM AUTHOR]

School eye screening is a crucial strategy in the elimination of childhood blindness because of its ability to reach out to children who are otherwise inaccessible to eye care needs. Comprehensive screening programs are recommended and are beneficial, but the economic aspects of such models remain to be understood. This study aimed to analyse the cost of a comprehensive school eye screening model while utilizing optometrists and optometry students. This cross-sectional study was conducted for 295 schools screened in the academic year 2018–2019. The analysis was performed from the service provider's perspective including only the direct costs. Financial records were used for cost estimates. The outcome measures were cost per school and child, predictors for the cost, DALYs averted, cost of childhood blindness, and Benefit–Cost Ratio. A total of 65 094 children underwent screening from 295 schools. The median (IQR) cost per school and child for screening was $29.65 (29.65–44.34) and $0.66 (0.32–1.13). The regression model predicted that the cost of screening was dependent on school strength, number of screening personnel, distance of the schools, and deliverables. With the interventions to improve compliance, 14686.30 DALYs have been averted. Loss of productivity due to childhood blindness was estimated to be $339070.83. Screening for colour vision also had a Benefit–Cost ratio of greater than one. Cost of screening was low and the benefits were high while utilising optometrist and optometry students along with a comprehensive screening protocol. [ABSTRACT FROM AUTHOR]

Background: Diagnosing colour vision deficiency is vital, owing to its impact on the choice of career and activities of daily living. Conventional screening methods require frequent replacement due to soiling of the materials, and hence are expensive and not feasible for large-scale community screening. This study aims to construct and validate a new screening tool, Dalton's pseudo-isochromatic plates (PIP), addressing the disadvantages of the conventional methods.Methods: The two phases of the study included the construction and validation of the Dalton's PIP. Construction involved utilising specific wavelengths based on spectral tuning, selection of numerals as targets for the chart and identification of a material with durability and resistance to wear and tear. Validation of the chart was done against the 38-plate edition of Ishihara's PIP by two masked examiners for 1,019 school children aged between 11-17 years (mean ± SD: 14 ± 2 years) as part of a school eye-health program.Results: The sensitivity and the specificity of the Dalton's PIP was found to be 94.12 per cent (95% CI 71.31-99.85) and 99.60 per cent (95% CI 98.98-99.89) respectively and the positive and negative predictive values were 80 per cent and 99.90 per cent respectively. Dalton's PIP when used with a failure criterion of less than three plates correct in two screening sets had the maximum sensitivity and specificity and the area under the curve was 0.96 (95% CI 0.90-0.99, p < 0.05).Conclusion: The newly constructed Dalton's PIP is found to be a valid screening tool to detect congenital colour vision deficiency and is comparable to the Ishihara PIP. This screening tool with its shorter screening time, cost and longer durability would effectively serve in large-scale vision screening programs. [ABSTRACT FROM AUTHOR]

Background: Population-based studies on the prevalence of non-strabismic anomalies of binocular vision in ethnic Indians are more than two decades old. Based on indigenous normative data, the BAND (Binocular Vision Anomalies and Normative Data) study aims to report the prevalence of non-strabismic anomalies of binocular vision among school children in rural and urban Tamil Nadu.Methods: This population-based, cross-sectional study was designed to estimate the prevalence of non-strabismic anomalies of binocular vision in the rural and urban population of Tamil Nadu. In four schools, two each in rural and urban arms, 920 children in the age range of seven to 17 years were included in the study. Comprehensive binocular vision assessment was done for all children including evaluation of vergence and accommodative systems. In the first phase of the study, normative data of parameters of binocular vision were assessed followed by prevalence estimates of non-strabismic anomalies of binocular vision.Results: The mean and standard deviation of the age of the sample were 12.7 ± 2.7 years. The prevalence of non-strabismic anomalies of binocular vision in the urban and rural arms was found to be 31.5 and 29.6 per cent, respectively. Convergence insufficiency was the most prevalent (16.5 and 17.6 per cent in the urban and rural arms, respectively) among all the types of non-strabismic anomalies of binocular vision. There was no gender predilection and no statistically significant differences were observed between the rural and urban arms in the prevalence of non-strabismic anomalies of binocular vision (Z-test, p > 0.05). The prevalence of non-strabismic anomalies of binocular vision was found to be higher in the 13 to 17 years age group (36.2 per cent) compared to seven to 12 years (25.1 per cent) (Z-test, p < 0.05).Conclusion: Non-strabismic binocular vision anomalies are highly prevalent among school children and the prevalence increases with age. With increasing near visual demands in the higher grades, these anomalies could significantly impact the reading efficiency of children. Thus, it is recommended that screening for anomalies of binocular vision should be integrated into the conventional vision screening protocol. [ABSTRACT FROM AUTHOR]

Background: This population-based, cross-sectional study was designed to determine normative data for binocular vision and accommodative testing in rural and urban populations of Tamil Nadu.Methods: A sample of 936 was determined, based on a previous pilot study. The epidemiological field work included a comprehensive eye examination and a binocular vision and accommodative assessment carried out in a total of four public schools, two each in the rural and urban arms of Chennai. An overall sample of 3,024 children between seven and 17 years of age was screened in the four schools and 920 children were included in the study.Results: We found significant differences in expected values from the current clinical criteria for near point of convergence (NPC) with penlight, distance and near horizontal phorias, vergence facility, accommodation convergence/accommodation (AC/A) ratio, accommodative amplitudes, monocular and binocular accommodative facility (t-test: p < 0.001). The mean and standard deviation break/recovery values for NPC (in centimetres) with an accommodative target and penlight with red filter was 3 ± 3/4 ± 4 and 7 ± 5/10 ± 7, respectively. The mean accommodative amplitudes for the population could be estimated from the linear regression equation 16 - 0.3 × (age). The vergence facility was 12 ± 4 cycles/minute and 14 ± 4 cycles/minute in the seven to 10 and 11 to 17 age groups, respectively. Monocular accommodative facility was 11 ± 4 cycles/minute and 14 ± 5 cycles/minute and binocular accommodative facility was 10 ± 4 cycles/minute and 14 ± 5 cycles/minute in the seven to 12 and 13 to 17 age groups, respectively. The mean calculated AC/A ratio was 5.4 ± 0.6/1.Conclusion: The normative data for vergence and accommodative parameters for the Indian children between seven and 17 years of age are reported. The developmental trend of accommodation and vergence differences and significant differences in cut-off between the current data and available literature are reported. These differences have clinical implications for the interpretation, diagnosis and management of anomalies of binocular vision. [ABSTRACT FROM AUTHOR]