Zimbabwe Eyecare And Learning(ZEAL):Formative Research on Hyperopia and Educational Outcomes in Primary School Children
Study Details
Study Description
Brief Summary
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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:
-
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.
-
To accurately detect moderate to high hyperopia (≥ +2.00D) using four screening tests compared to the gold-standard cycloplegic refraction.
-
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:
-
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.
-
To compare spectacle compliance among newly diagnosed hyperopic and newly diagnosed myopic (short-sighted) school children at six weeks and 14 weeks.
Study Design
Arms and Interventions
| 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. |
Outcome Measures
Primary Outcome Measures
- Prevalence of moderate to high hyperopia (≥ +2.00D) [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
- Binocular near visual acuity [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.
- Accommodative response [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.
- Presence of eye conditions [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.
- Stereoacuity [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
- Improvement in near visual acuity on prescribing hyperopic spectacle correction [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.
- Change of reading scores 6 months post hyperopia spectacle correction [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
- Observed spectacle wear [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
Eligibility Criteria
Criteria
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).
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | The University of Zimbabwe, Faculty of Medicine and Healthcare Sciences | Harare | Zimbabwe | P.O. Box A178 |
Sponsors and Collaborators
- Queen's University, Belfast
- L.V. Prasad Eye Institute
- University of Zimbabwe
- University of Ulster
- New England College of Optometry
- Peek Vision
- Zimbabwe Optometric Association
- Clearly
- 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
Study Documents (Full-Text)
None provided.More Information
Publications
- Atkinson J, Braddick O, Nardini M, Anker S. Infant hyperopia: detection, distribution, changes and correlates-outcomes from the cambridge infant screening programs. Optom Vis Sci. 2007 Feb;84(2):84-96. Review.
- Babinsky E, Candy TR. Why do only some hyperopes become strabismic? Invest Ophthalmol Vis Sci. 2013 Jul 24;54(7):4941-55. doi: 10.1167/iovs.12-10670. Review.
- French AN, O'Donoghue L, Morgan IG, Saunders KJ, Mitchell P, Rose KA. Comparison of refraction and ocular biometry in European Caucasian children living in Northern Ireland and Sydney, Australia. Invest Ophthalmol Vis Sci. 2012 Jun 26;53(7):4021-31. doi: 10.1167/iovs.12-9556.
- Glewwe P, Park A, Zhao M. A better vision for development: Eyeglasses and academic performance in rural primary schools in China. J Dev Econ. 2016;122:170-82.
- Glewwe P, West KL, Lee J. The Impact of Providing Vision Screening and Free Eyeglasses on Academic Outcomes: Evidence from a Randomized Trial in Title I Elementary Schools in Florida. J Policy Anal Manage. 2018;37(2):265-300. doi: 10.1002/pam.
- Hashemi H, Fotouhi A, Yekta A, Pakzad R, Ostadimoghaddam H, Khabazkhoob M. Global and regional estimates of prevalence of refractive errors: Systematic review and meta-analysis. J Curr Ophthalmol. 2017 Sep 27;30(1):3-22. doi: 10.1016/j.joco.2017.08.009. eCollection 2018 Mar. Review.
- Ma X, Zhou Z, Yi H, Pang X, Shi Y, Chen Q, Meltzer ME, le Cessie S, He M, Rozelle S, Liu Y, Congdon N. Effect of providing free glasses on children's educational outcomes in China: cluster randomized controlled trial. BMJ. 2014 Sep 23;349:g5740. doi: 10.1136/bmj.g5740.
- Ma Y, Congdon N, Shi Y, Hogg R, Medina A, Boswell M, Rozelle S, Iyer M. Effect of a Local Vision Care Center on Eyeglasses Use and School Performance in Rural China: A Cluster Randomized Clinical Trial. JAMA Ophthalmol. 2018 Jul 1;136(7):731-737. doi: 10.1001/jamaophthalmol.2018.1329.
- Naidoo KS, Raghunandan A, Mashige KP, Govender P, Holden BA, Pokharel GP, Ellwein LB. Refractive error and visual impairment in African children in South Africa. Invest Ophthalmol Vis Sci. 2003 Sep;44(9):3764-70.
- Narayanasamy S, Vincent SJ, Sampson GP, Wood JM. Impact of simulated hyperopia on academic-related performance in children. Optom Vis Sci. 2015 Feb;92(2):227-36. doi: 10.1097/OPX.0000000000000467.
- O'Donoghue L, McClelland JF, Logan NS, Rudnicka AR, Owen CG, Saunders KJ. Refractive error and visual impairment in school children in Northern Ireland. Br J Ophthalmol. 2010 Sep;94(9):1155-9. doi: 10.1136/bjo.2009.176040. Epub 2010 May 21.
- Rosner J, Rosner J. The relationship between moderate hyperopia and academic achievement: how much plus is enough? J Am Optom Assoc. 1997 Oct;68(10):648-50.
- Shankar S, Evans MA, Bobier WR. Hyperopia and emergent literacy of young children: pilot study. Optom Vis Sci. 2007 Nov;84(11):1031-8.
- Slavin RE, Collins ME, Repka MX, Friedman DS, Mudie LI, Owoeye JO, et al. In Plain Sight: Reading Outcomes of Providing Eyeglasses to Disadvantaged Children. J Educ Stud Placed Risk. 2018;23(3):250-8.
- VIP-HIP Study Group, Kulp MT, Ciner E, Maguire M, Moore B, Pentimonti J, Pistilli M, Cyert L, Candy TR, Quinn G, Ying GS. Uncorrected Hyperopia and Preschool Early Literacy: Results of the Vision in Preschoolers-Hyperopia in Preschoolers (VIP-HIP) Study. Ophthalmology. 2016 Apr;123(4):681-9. doi: 10.1016/j.ophtha.2015.11.023. Epub 2016 Jan 27.
- White SLJ, Wood JM, Black AA, Hopkins S. Vision screening outcomes of Grade 3 children in Australia: Differences in academic achievement. Int J Educ Res. 2017;83:154-9.
- Williams WR, Latif AH, Hannington L, Watkins DR. Hyperopia and educational attainment in a primary school cohort. Arch Dis Child. 2005 Feb;90(2):150-3.
- ENGINE-ZEAL-TP