Refractive Errors
Conditions
Keywords
Myopia, Hyperopia, Spectacle correction, Educational outcomes
Brief summary
The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone. The procedures include baseline questionnaires and educational assessments to collect data on students and schools, and then the provision of free eyeglasses to students who have uncorrected (or undercorrected) refractive error (URE). The questionnaires and student assessments will take 1-2 hours. The duration of the study timeframe is one school year. The end-line questionnaires and student assessments will be administered at the end of the school year.
Detailed description
Objective: The main objective of the Sierra Leone Sees to Learn (SL2) trial is to assess the educational impact of providing free eyeglasses to students aged 9-20 years with uncorrected refractive error in Sierra Leone. Sample frame: Approximately 2400 children with uncorrected (or undercorrected) refractive error (URE) at 300 randomly-selected schools in Freetown and Bo City. A similar number of children from the same schools but without vision problems will also be included, at baseline only, to compare their basic demographic characteristics and daily activities to those of the children with URE. The sample size may vary depending on the percentage of children with URE obtained from screening a total of 40,000 children. All children with URE as specified in the enrolment criteria below will be part of the study. Design: Cluster-randomized control trial (cluster RCT), with schools as clusters. Randomization, interventions and balancing: All eligible children will be randomized by school to receive at the start of the school year either: free ready-made or custom eyeglasses (Intervention), or an eyeglasses prescription and letter to parents, with free eyeglasses at end-line (Control). The clusters (schools) will be stratified into groups based on the prevalence of refractive error and on the score on the baseline mathematics and reading exams. The division of the sample into schools in the two cities (Bo and Freetown) will be in the same proportion as the proportion of the number of public schools in those two cities. Power calculations (reading and math exams): Setting power = 0.8, statistical precision = 0.05, intracluster correlation = 0.2 (from 2019 Sierra Leone grade 8 learning assessment), 80 treated schools, 80 control schools, 15 students/school with uncorrected error, yields the following minimal detectable effect (MDE) sizes as a function of correlation between baseline and end-line tests: MDE Correlation of baseline and end-line tests 0.101 0.7 0.127 0.6 0.148 0.5 A nested focus-group study will explore children's, parents' and teachers' attitudes towards vision, student learning, and wearing of eyeglasses, in order to design a locally-tailored intervention to promote wearing of eyeglasses. Regression Framework: The investigators will estimate the effect of the program using a single difference cross-sectional ordinary least squares regression (OLS), and a difference-in-difference (DID) OLS regression that includes observations at both end-line and baseline. The investigators will report two types of effects: the intent-to-treat (ITT) effects and local average treatment effects (LATE), using treatment assignment as an instrumental variable for participation. Analysis will use the observed baseline characteristics as control variables and account for school-level variation through a fixed effect.
Interventions
DEVICEEyeglasses
Children with uncorrected/under-corrected refractive error will be provided with either ready made or custom eyeglasses based on their magnitude and types of refractive errors.
OTHERPrescription slip
Children with uncorrected/under-corrected refractive error will be provided with an eyeglasses prescription and letter to parents, but all of them will get eyeglasses at the end of the trial
Sponsors
University of Minnesota
Innovations for Poverty Action
Peek Vision
Vision Action
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Investigator, Outcomes Assessor)
Masking description
Participants will be given either glasses or a prescription. Hence, they could not be masked. The Care Provider, in our case, screening and examination team will be providing either glasses or prescriptions to the participants. Hence, they could not masked. Investigators and Outcome assessor will only analyse the data at the end of the trial and they will not be
Intervention model description
All eligible children will be randomized by school to receive at the start of the school year either: free ready-made or custom eyeglasses (Intervention), or an eyeglasses prescription and letter to parents, with free eyeglasses at endline (Control). The clusters (schools) will be stratified into groups based on the prevalence of refractive error and on the score on the baseline mathematics and reading exams. The division of the sample into schools in the two cities (Bo and Freetown) will be in the same proportion as the proportion of the number of public schools in those two cities.
Eligibility
Sex/Gender
ALL
Age
9 Years to 20 Years
Healthy volunteers
No
Inclusion criteria
1. Presenting (with or without glasses) distance visual acuity of 6/12 or worse in the better-seeing eye; 2. Refractive error of at least 0.75 diopters (D) of myopia, 2.00 D of hyperopia or 1.00 D of astigmatism; 3. Visual acuity is correctable to 6/7.5 or better with eyeglasses.
Exclusion criteria
1\. Other ocular problems preventing visual acuity \> 6/12 in both eyes.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Foundational mathematic and literacy skills | Month 1 and 9 months after glasses are provided | Item Response Theory to estimate a student's ability on a continuous scale and subsequently standardize students' scores on a continuous scale with respect to the control-group distribution at baseline (mean zero, standard deviation of one). Lower scores will indicate lower performance, and higher scores will indicate higher performance. A -1 would indicate a student's performance is 1 standard deviation below the mean of the control-group performance distribution at baseline. A zero would mean the student performed like the mean student in the control group at baseline. |
| Anxiety | Month 1 and 9 months after glasses are provided | Measured using Generalized Anxiety Disorder 2-item (GAD-2) questionnaire, the highest score is 8 and the lowest score is 2. Higher scores indicated more severe anxiety disorders. |
| Prosocial | Month 1 and 9 months after glasses are provided | Measured using Strengths \& Difficulties Questionnaire with the prosocial score ranges from 0 to 10 and higher scores indicate more prosocial behaviour. |
| Social and emotional problems | Month 1 and 9 months after glasses are provided | Measured using Strengths \& Difficulties Questionnaire with the score ranges from 0 to 40. Higher scores indicate more social and emotional problems. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Teacher-observed wearing of eyeglasses of children | Month 1 to Month 9 after glasses are provided | Proportion of children observed wear across all children at daily assessments |
| Self-reported wearing of eyeglasses compliance | Month 9 after glasses are provided | Proportion of children who reported to be wearing their eyeglasses 1. Not at all 2. Sometimes 3. Most of the time 4. All the time |
| Enumerator-observed wearing of eyeglasses | At Months 3, 6 and 9 after glasses are provided | Actual presence of spectacles on the child's face (rather than having glasses at school) at the time of an unannounced examination |
| Cost-effectiveness 1 | Through study completion, an average of 9 months | Total eyeglasses distribution cost (excluding study cost) per child receiving, and wearing, eyeglasses at endline |
| Cost-effectiveness 2 | Through study completion, an average of 9 months | Total eyeglasses distribution cost (excluding study cost) per 0.1 standard deviation test score gain |
| School attendance | Daily from Month 1 to Month 9 | Attendance data will be collected from attendance registry at school. This will be expressed in percentage. Lowest attendance being 0%, highest being 100%. |
Countries
Sierra Leone
Contacts
PRINCIPAL_INVESTIGATORNathan Congdon, MD
Queen's University, Belfast
Outcome results
None listed