Background
Methods
Results
Characteristics of the eligible studies
Authors/ year of publication/ Study design | Population (age range or grade level) at study enrolment/ Geographic Location/ Country Profile/ Study setting | Intervention/Type of refractive error corrected | Comparison | Tools and methods used | OUTCOME/KEY FINDINGS | Sampling Method | Sample Size | Limitations | Strengths | Recommendations |
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Hannum and Zhang / 2012 / RCT [59] | 9–12 years old / China / LMIC / Rural | Spectacle correction / Not specified | Children who did not receive spectacle correction | – Literacy assessment – A curriculum-based math achievement test – A curriculum-based language achievement test | Spectacle correction had a significant favourable effect on math and literacy performance and class failure: – Literacy outcome: effect was 0.34 SD (95% CI: 0.130–0.557) – Math achievement outcome: effect is 0.26 SD (95% CI: 0.052–0.462) – Language achievement outcome: the effect was not significant – Children who received glasses from this project were 35% less likely to fail a class (p < 0.01) | Randomisation at the township level | 19,185 | It was uncertain if the strategy for matching the treatment and control groups could account for pertinent differences in confounding variables | – The randomised nature of the trial by count – The use of curriculum-based achievement tests | The selectivity issues in the study suggest that further empirical studies are needed to test the impact of vision correction on learning outcomes |
Van Rijn / 2014 / RCT [62] | 9–10 years old / Netherlands / HIC / Urban | Spectacle correction / Hyperopia | Differing magnitudes of refractive correction | Reading speeed tests: – Klepel (reading speed of nonwords) – The One-Minute Test (reading speed of genuine words) | Differing impact of spectacle correction on reading speed using the Klepel and one-minute reading speed tests was recorded for subjects myopia and hyperopia: – Myopes showed a small (2.44, CI: 0.39–4.49) and significant (p = 0.021) difference from baseline to follow-up with the Klepel test; Analysis of the impact of spectacle correction on reading speed amongst hyperopes found: – Hyperopes with full prescription showed a significant (p = 0.012) increase (8.77, CI: 1.59–15.93) compared to no correction and the group receiving 0.50 prescription (8.40, CI: 1.09–15.71; p = 0.019) | Randomisation of subjects in the treatment arm | 191 | – The small sample size did not allow unequivocal conclusions to be made – The instantaneous measurement of reading speed did not allow an assessment of the frequency of spectacle wear and its impact – There was no masking between the groups receiving and not receiving spectacle correction – A large number of subjects were lost to follow-up | – The subjects recruited for this study were those who did not plan to receive a prescription | A larger study is recommended with larger sample size |
Harvey et al / 2016 [60] / Cross-sectional | Grade 3–8 / USA / HIC / Urban | Spectacle correction /Astigmatism | Differing levels of astigmatism | – Oral Reading Fluency test: Dynamic Indicators of Basic Early Literacy Skills (DIBELS) | This cross-sectional study found that: – Spectacle correction resulted in improved oral reading fluency (ORF) in subjects with astigmatism o High astigmats showed a mean improvement in ORF of 6.05 words per minute with spectacle correction o Moderate astigmats showed a mean improvement in ORF of 1.87 words per minute with spectacle correction | Purposive sampling of astigmatic students | 273 | – Use of grade level rather than age across groups – Absence of data on the effects of text size and near acuity on ORF in the sample – The study did not measure the impact of spectacle correction over time due to its cross-sectional nature | – Large school-based sample of bilateral astigmats with with-the-rule astigmatism – A comparison group of students with low or no astigmatism from the same cohort – Use of a well-validated tool to measure Oral Reading Fluency | – Individuals with high astigmatism should adhere to full-time spectacle wear |
Dudovitz et al / 2016 [17] / Qualitative | 5–14 years old / USA / HIC / Urban | Spectacle correction / Not specified | None | – Focus Group Interviews | This qualitative study investigated the relationship between vision care, students’ academic performance, classroom behaviour and psychosocial well-being using focus groups with students, their families and teachers The study found the following: – Obtaining glasses resulted in improved school function due to: o Better grades and academic performance o Improved reading ability o Increased willingness to practice academic skills and o More accuracy in math-related homework – Less disruptive behaviour in the classroom resulted in an enhanced learning environment – Greater ease in completing homework | Convenience | 21 | – The qualitative study nature may result in an over-representation of specific participant contributions – Aggregate group data may not reflect the specific concerns of each participant within the group – Convenience sampling has likely caused selection bias, limiting generalisation to all parents, teachers, and children served by the VTL programme | – Forging stronger partnerships between education and health sectors, schools serve as a vehicle for health service delivery and a platform for changing social and cultural norms – Results from this study can inform school and health policy for visual screening and referral services for students | – Forging stronger partnerships between education and health sectors, schools serve as a vehicle for health service delivery and a platform for changing social and cultural norms |
Ma et al / 2018 / RCT [61] | 10–12 years old / China / LMIC / Rural | Spectacle correction / Not specified | Late referral group | – A standardised Mathematics test | Early provision of spectacles improved children’s academic performance – Effect on mathematics scores was 0.25 SD (95% CI: 0.01–0.48; p = 0.04) | Cluster Randomisation | 949 | – All schools were taken from one county in rural northwest China, thereby limiting external validity – The unadjusted effect size of the main study outcome was not statistically significant – A modest follow-up of 79% | – The randomised design of the study – The use of population-based sampling | The calculation of program costs and economic modelling was recommended for the future |
Nie et al / 2019 [20] / RCT | Grade 7–8 / China / LMIC / Rural | Spectacle correction / Myopia | Children receiving a prescription to purchase spectacles | – Standardised maths exam – Aspiration of further schooling – School dropout behaviour | This RCT which explored the impact of free spectacles on student’s math scores, aspirations for further schooling and dropout behaviour, found: – Improved math scores by approximately 0.14 SD; – raised aspirations to attend academic high school by nine percentage points; – reduced dropout by 44% during the school year Subjects without spectacles at baseline displayed the greatest increase in math scores of 0.196 SD than those with spectacles at baseline | Cluster Randomisation | 979 | – The study was conducted in one poor region of western China, and therefore findings may not be applied to other settings Effects on the dropout and other study outcomes could only be examined over the school year, making it possible that the intervention delayed students’ decisions to leave school until after the end of the school year | – The results of the study adds to the body of knowledge on the effect of spectacle provision on student academic performance | The subsidisation of spectacles for myopic students in China and other developing countries |
Dudovitz et al / 2020 [18] / Cohort | Elementary school / USA / HIC / Urban | Spectacle correction / Not specified | Non-participating same grade peers who did not receive glasses | – Achievement marks in Mathematics, English language Arts (ELA) – Work habits – Behaviour rank | This cohort study which investigated grades in ELA and Mathematics, work habits and behaviour, found the following after receiving spectacles: – Subjects showed significant, improved ELA achievement rank in the fifth grading period of 5.07 (P = .001) and the sixth grading period of 3.38 PP (p = 0.03) – While there was no significant change in overall math achievement, subjects performing in the lower tercile showed an immediate and sustained improvement of 10 to 24 PP from baseline – There was no significant improvement in work habits over the two years follow-up period – There was a decrease in behaviour rank during the fourth grading period of 3.9 PP (p = 0.01), which returned to baseline levels during the fifth and sixth grading periods | Purposive sampling of VTL students | 406 | – The observational study design makes it impossible to attribute causation to improved school performance – Using class rank rather than grades or test scores allowed the researchers to account for school-level differences. However, it prevented classroom-level differences – It was likely that were unmeasured differences between participants and non-participants – Since the sample was mainly low-income Latino gathered from a single, large, urban school district. The results were more likely not generalisable to other populations | The study provides a quantitative assessment of whether school-based vision care improves grades among US elementary students | – Future studies to explore potential differences by VI diagnosis, age or grade level and socio-demographics |
The impact of spectacle correction on children’s cognitive and educational well-being
The psychological and mental health impact of spectacle correction
Quality of life impact of spectacle correction
Authors/ year of publication/ Study design | Population (age range or grade level) at study enrolment / Geographic Location / Country Profile / Study setting | Intervention / Type of refractive error corrected | Comparison | Tools and methods used | OUTCOME/KEY FINDINGS | Sampling Method | Sample Size | Limitations | Strengths | Recommendations | |
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Guan et al / (2018) / RCT [58] | 9–12 years old / China / LMIC / Rural | Spectacle correction / Myopia | Students who received only prescriptions | – Mental Health Test (MHT) with special attention to learning anxiety and physical anxiety | The impact of providing fully subsidised glasses on mental health resulted in the following: – When considering the total sample, glasses resulted in a 0.08 decrease in physical anxiety (p < 0.1) Sub-group analysis revealed the following: – Students who studied at a low-intensity level (studying for less than half an hour per day) experienced a 0.17SD increase in Learning Anxiety (p < 0.05) – Students who studied at a high-intensity level (studying more than two hours per day) experienced: o 0.25 SD decline in Learning Anxiety (p < 0.1); o 0.22 SD decline in Physical Anxiety (p < 0.1); o 0.26 SD improvement in MHT score (p < 0.05) – Students who studied at a moderate degree of intensity (studying between half an hour to two hours per day) experienced a 0.13 decline in MHT score (p < 0.05) | Randomisation of schools to TG and CG | 2851 | – Average treatment recorded could have masked heterogenous effects | – Large sample size Randomised study design | – Need to boost wear rates of glasses among students – Care must be taken to eliminate teasing of students who are newly wearing glasses Spectacles should be promoted as a learning asset among children |
Authors/ year of publication/ Study design | Population (age range or grade level) at study enrolment/ Geographic Location/Country Profile/Study setting | Intervention/Type of refractive error corrected | Comparison | Tools and methods used | OUTCOME/KEY FINDINGS | Sampling Method | Sample Size | Limitations | Strengths | Recommendations |
---|---|---|---|---|---|---|---|---|---|---|
Zhou et al. / (2016) / RCT | 12–15 years old / China / LMIC/ Rural | Spectacle correction/ Myopia | Differing spectacle prescriptions determined by an optometrist, self-refraction, rural refractionist and ready-made spectacles | – National Eye Institute Refractive Error Quality of Life-42 (NEI-RQL-42) questionnaire | The National Eye Institute Refractive Error Quality of Life questionnaire assessing the visual function-related quality of life showed increases in scores from the baseline assessment of: – 2.32 [95% CI (0.37, 4.27) p = 0.020] in the group tested by an optometrist – 4.65 [95% CI (2.45, 6.86) p < 0.001] in the group receiving ready-made spectacles – 4.13 [95% CI (2.04, 6.23) p < 0.001] in the group tested by a rural refractionist – 3.14 [95% CI (1.05, 5.23) p = 0.004] in the self-refraction group Irrespective of the type of spectacles or method of correction, all findings reveal an increase in quality-of-life scores with correction | Randomisation of subjects to TG (3 groups) and CG | 542 | – The enrolled schools were selected using non-random sampling – All schools were drawn from a single region in southern China, thereby limiting the application of findings from the study to other contexts | – The study followed a randomised controlled design – The study had a high follow-up rate | – Further research is needed to assess the acceptability of adjustable spectacles for actual wear by adults and children |
Quality appraisal of studies
Randomised control trials | Aspect of Well-being | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 | Q10 | Q11 | Quality % rating |
Guan et al 2018 [58] | Psychological and mental health | ✓ | ✓ | ✓ | ± | ✓ | x | ✓ | x | x | x | ✓ | 54.5 |
Hannum & Zhang 2012 [59] | Cognitive and education | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | x | x | ✓ | ✓ | 81.8 |
Ma et al 2018 [61] | Cognitive and education | ✓ | ✓ | ✓ | ± | ✓ | ✓ | ✓ | x | x | ✓ | ✓ | 72.7 |
Nie et al 2019 [20] | Cognitive and education | ✓ | ✓ | ✓ | ± | ✓ | ✓ | ✓ | x | ✓ | ✓ | ✓ | 81.8 |
Van Rijn 2014 [62] | Cognitive and education | ✓ | ✓ | ✓ | x | ✓ | ✓ | ✓ | ✓ | x | x | ✓ | 72.7 |
Zhou et al 2016 [63] | Quality of life | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | x | ✓ | ✓ | 90.9 |
Cohort study | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 | Q10 | Q11 | ||
Dudovitz et al. 2020 [18] | Cognitive and education | ✓ | ✓ | ± | ✓ | ✓ | ✓ | ± | ✓ | ± | ± | ✓ | 63.6 |
Cross-sectional study | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | |||||
Harvey et al 2016 [60] | Cognitive and education | ✓ | ✓ | ✓ | ✓ | ± | ✓ | ✓ | ✓ | 87.5 | |||
Qualitative study | Q1 | Q2 | Q3 | Q4 | Q5 | Q6 | Q7 | Q8 | Q9 | Q10 | |||
Dudovitz 2016 [17] | Cognitive and education | ✓ | ✓ | ✓ | ✓ | ✓ | ± | ✓ | ✓ | ✓ | ✓ | 90.0 |