Zimbabwe Eyecare And Learning(ZEAL):Formative Research on Hyperopia and Educational Outcomes in Primary School Children (ZEAL)

February 29, 2024 updated by: Nathan Congdon, Queen's University, Belfast

Zimbabwe Eyecare And Learning: Formative Research on Hyperopia and Educational Outcomes in Primary School Children in Mashonaland Central Province of Zimbabwe

The purpose of this study is to determine whether uncorrected or corrected long-sightedness (hyperopia) has an impact on reading skills, in Grade 2 or Grade 4 school-aged children from Mashonaland Central province of Zimbabwe, compared to age-, gender- and school-matched children with no refractive error (emmetropia), measured by the Happy Readers V4 reading tool over six months.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Trials in Asia have shown that correction of myopia (close-sightedness) in children has improved educational performance with an effect size larger than for any other school-based health intervention. Myopia prevalence which is, generally inversely associated with the prevalence of hyperopia, appears low in African children. Globally, uncorrected hyperopia (long-sightedness) has a higher prevalence and is present in 12-26% of children, depending on location and age, but the impact of its correction on educational outcomes is not well understood. All-age prevalence of hyperopia is higher in Africa than in any other global region. Despite the traditional view that moderate hyperopia is generally benign, emerging evidence suggests that even moderate uncorrected hyperopia is associated with reduced near function, poorer educational outcomes and lower reading scores. A recent trial in the USA showed that providing refractive correction improved reading scores but did not distinguish between myopia and hyperopia. Another trial in the USA found only small benefits from refractive correction in 1- to 2-year-olds. However, no trial to date has studied the educational impact of hyperopic correction in school-aged children with +2.00 Dioptres (D) or more of hyperopia.

While the gold standard for detecting hyperopia in children during vision examinations requires cycloplegic eye drops to temporarily inhibit accommodation (focusing effort to see near objects), using these eye drops requires trained providers and clinical supervision. It is not typically feasible in vision screening settings. The Vision in Preschoolers study showed that two autorefractors (Retinomax, SureSight) and non-cycloplegic retinoscopy had high discriminatory power to detect young children with hyperopia. However, non-cycloplegic retinoscopy requires trained providers, SureSight is no longer commercially available, and the Retinomax is cost-prohibitive for many screening programs. This limits the availability of hyperopia prevalence data in African children, though, as noted above, available evidence suggests high rates. Most screening programmes use 6/12 as an optimal cut-off value for distance vision. However, studies have reported that measuring distance vision alone is ineffective in detecting hyperopia. Literacy rates remain particularly low among primary school children in sub-Saharan Africa compared to other regions. The challenges and importance of maximising children's early learning, and the potentially important role of vision correction, are not well-understood in this setting. However, these initiatives have focused on myopia, not hyperopia.

Study plan: 2000 study participants (1000: Grade 2, 1000: Grade 4) will be recruited from primary schools selected by the Ministry of Primary and Secondary Education (MoPSE) in Mashonaland Central province in Zimbabwe.

Study design:

Objectives 1, 2 and 3 use a cross-sectional study design to assess the following:

  1. To assess the prevalence of moderate to high hyperopia (≥ +2.00D) among primary school children in Grades 2 and 4 from Mashonaland Central province in Zimbabwe.
  2. To accurately detect moderate to high hyperopia (≥ +2.00D) using four screening tests compared to the gold-standard cycloplegic refraction.

  3. To study the association between uncorrected and corrected moderate to high hyperopia (≥ +2.00D) and baseline reading levels.

    Objectives 4 and 5 use a longitudinal intervention design to assess the following:

  4. To compare near visual acuity and reading levels at baseline and at six months between moderate to high hyperopic (≥ +2.00D) children compared to age-, gender-, and school-matched controls with no vision problems.
  5. To compare spectacle compliance among newly diagnosed hyperopic and newly diagnosed myopic (short-sighted) school children at six weeks and 14 weeks.

Study Type

Interventional

Enrollment (Actual)

1883

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Zimbabwe
      • Harare, Zimbabwe, P.O. Box A178
        • The University of Zimbabwe, Faculty of Medicine and Healthcare Sciences

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

6 years to 11 years (Child)

Accepts Healthy Volunteers

Yes

Description

Inclusion criteria for the cross-sectional assessment of hyperopia prevalence and diagnostic tool development evaluation:

  • Grades 2 or 4 from the list of selected primary schools by the Ministry of Primary and Secondary Education (MoPSE)

Inclusion criteria for the baseline and longitudinal assessment of reading performance

Primary school children will be eligible to participate in the 'reading assessment' if they fulfil the following criteria:

Hyperopic cohort:

  • In Grade 2 or 4 from the list of selected schools by the MoPSE.
  • Presence of moderate to high hyperopia, defined as ≥ +2.00D in the more hyperopic meridian, in the more hyperopic eye, using cycloplegic autorefraction with an average of three consecutive readings taken.

Emmetropic cohort:

  • In Grade 2 or 4 from the list of selected schools by the MoPSE.
  • Meets criteria for visually normal (unaided distance visual acuity 6/6 monocular and near visual acuity N5), based on an absence of significant refractive error.
  • Presence of emmetropia, defined as < +1.00D to >-0.50 Dioptre in the more hyperopic meridian, in both eyes using cycloplegic autorefraction with an average of three consecutive readings taken to record the refractive status.

Newly diagnosed hyperopic and newly diagnosed myopic children will be eligible to participate in the 'spectacle compliance' assessment if they fulfil the following criteria:

Hyperopic cohort:

  • Presence of hyperopia, defined as ≥ +2.00D in the more hyperopic meridian, in the more hyperopic eye by cycloplegic autorefraction.

Myopic cohort:

  • Presence of myopia, defined as <-0.50D in the more hyperopic meridian, in either eye by cycloplegic autorefraction.

Exclusion criteria for the baseline and longitudinal assessment of reading performance and spectacle compliance.

Children in either cohort will be ineligible if they have:

  • History of systemic disease or ocular disease and/or medications known to have an impact on accommodation.
  • History of previous spectacle wear

Children in the hyperopic cohort will be ineligible if they have:

  • Vision limitation in either eye for reasons other than hyperopia (including amblyopia defined as <6/12 in the better eye).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Spectacles

Based on the refraction results, spectacles will be prescribed at the baseline visit and worn throughout the study. Study participants with newly diagnosed hyperopia at baseline will undergo a reading assessment and near visual acuity check over six months, compared to age-, gender- and school-matched emmetropic controls.

Spectacle compliance will be observed among newly diagnosed hyperopic and newly diagnosed myopic school children in Grades 2 and 4 primary school children, from Mashonaland Central province of Zimbabwe, at six weeks and 14 weeks from spectacle acquisition.
Device: Spectacles
Based on the refraction results, study participants diagnosed with refractive error will be dispensed two free pairs of distance spectacles.
No Intervention: No treatment
Age-, gender- and school-matched emmetropic controls will undergo a reading assessment at baseline and at six months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Prevalence of moderate to high hyperopia (≥ +2.00D)
Time Frame: Measured at baseline
The metric or method of measurement to be used:The Average of three readings(in dioptre)using cycloplegic autorefraction for each eye. Higher dioptre indicates high hyperopia
Measured at baseline
Binocular near visual acuity
Time Frame: Measured at baseline
The metric or method of measurement to be used: Logarithm of Minimum Angle of Resolution(LogMAR) measured using the laser-etched near vision chart with Lea symbols at 12.5 cm.
Measured at baseline
Accommodative response
Time Frame: Measured at baseline
The metric or method of measurement to be used: binocular distance autorefraction measured at 3 metres and monocular near refraction measured at 25cm using the Quick See autorefractor.
Measured at baseline
Presence of eye conditions
Time Frame: Measured at baseline
The metric or method of measurement to be used: assessing the overall appearance of the fundus reflex in both eyes(Bruckner Reflex Test) as an indicator of the prevalence of refractive error using the Arclight ophthalmoscope. This will be a binary outcome of Yes or No.
Measured at baseline
Stereoacuity
Time Frame: Measured at baseline

The metric or method of measurement to be used: measured in seconds of arc using the Preschool Assessment of Stereopsis with a Smile (PASS) 3+ stereoacuity test (scores: 480, 240, 120, 60, 40 and 30). Seconds of arc refers to the visual angle being measured to determine depth perception. Lower scores indicate better stereoacuity.

Highest possible score: 480 Lowest possible score: 30
Measured at baseline
Improvement in near visual acuity on prescribing hyperopic spectacle correction
Time Frame: Measured at baseline,2 weeks and 24 weeks after baseline
The metric or method of measurement to be used: measured in M-unit using a conventional near vision chart with Lea symbols at 40cm.
Measured at baseline,2 weeks and 24 weeks after baseline
Change of reading scores 6 months post hyperopia spectacle correction
Time Frame: Measured at baseline and at month -6

The metric or method of measurement to be used: Reading scores measured using the Happy Readers V4 reading test.

Best possible score: Improvement from baseline Worst possible score: No change from baseline
Measured at baseline and at month -6
Observed spectacle wear
Time Frame: Measured at week 6 and week 14 from baseline
The metric or method of measurement to be used: proportion of children prescribed with spectacles, wearing them during unannounced direct observation
Measured at week 6 and week 14 from baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Queen's University, Belfast

Collaborators

University of Ulster
University of Zimbabwe
L.V. Prasad Eye Institute
Clearly
New England College of Optometry
Peek Vision
Zimbabwe Optometric Association
Christian Blind Mission

Investigators

  • Principal Investigator: Nathan G Congdon, MD, MPH, Queen's University, Belfast
  • Principal Investigator: Rohit C Khanna, MPH, L.V. Prasad Eye Institute
  • Principal Investigator: Lynett E Masiwa, MSc, University of Zimbabwe
  • Principal Investigator: Rangarirai Masanganise, University of Zimbabwe

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 1, 2022

Primary Completion (Actual)

July 28, 2023

Study Completion (Actual)

July 28, 2023

Study Registration Dates

First Submitted

September 9, 2022

First Submitted That Met QC Criteria

September 9, 2022

First Posted (Actual)

September 13, 2022

Study Record Updates

Last Update Posted (Estimated)

March 1, 2024

Last Update Submitted That Met QC Criteria

February 29, 2024

Last Verified

February 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MHLS 22_63

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

All Individual Participant Data (IPD) will be stored in an anonymised format. The IPD that includes personally identifiable information will be deleted when the data collection process is complete and before the initiation of data analysis.

Only de-identified data will be shared with all the researchers for analysis. The primary analysis will be conducted on all outcome data obtained from all enrolled participants as randomised.

IPD Sharing Time Frame

All deidentified IPD will be available from June 2022 (anticipated Trial start date) to December 2032 (inclusive of analysis, publication and archival).

IPD Sharing Access Criteria

Following publication of the primary outcomes there may be scope to conduct additional analyses on the data collected. In such instances formal requests for data will need to be made in writing to the Chief Investigator, who will discuss this with the Sponsor. The study will comply with the good practice principles for sharing individual participant data from publicly funded clinical trials and data sharing will be undertaken in accordance with the required regulatory requirements.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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