Sage Journals: Discover world-class research

Abstract

Objective:

Refractive errors are most common ocular disorders among children and adolescents. They remain as secondary causes of avoidable blindness in impoverished areas in Africa, most notably in Ethiopia. The problem worsens if it is not managed and addressed early. The aim of this systematic review and meta-analysis was to determine the prevalence of refractive errors among school students in Ethiopia.

Methods:

We searched international databases such as PubMed/Medline, Web of Science, CINAHL, Embase, Scopus, Cochrane Library, Google Scholar, and Science Direct for relevant articles. Data were extracted using Microsoft Excel and exported to Stata version 14.0 software for analysis. The Cochrane Q and I² tests were used to assess heterogeneity. Funnel plot, Egger’s, and Begg’s tests were used to assess reporting bias. Random effect meta-analysis model was employed to estimate pooled prevalence of refractive errors. A regional subgroup analysis was carried out.

Results:

We reviewed 22 qualified studies with 23,355 study participants. The overall prevalence of refractive errors among school students was 7.36% (95% confidence interval = 6.05, 8.67). The prevalence of myopia, hyperopia, and astigmatism was 5.10% (95% confidence interval = 3.79, 6.40), 0.95% (95% confidence interval = 0.59, 1.31), and 0.01% (95% confidence interval = 0.01, 0.04), respectively. From subgroup analysis, the highest prevalence of refractive errors was reported in Amhara Region (9.18%, 95% confidence interval = 6.63, 11.74), followed by Southern Nations, Nationalities, and Peoples’ region (6.78%, 95% confidence interval = 4.65, 8.92) while the lowest prevalence of refractive errors was reported in Addis Ababa (3.93%, 95% confidence interval = 3.30, 4.56).

Conclusion:

In Ethiopia, the prevalence of refractive errors among school students is higher (7.36%) compared to what it was 5 years (7.05%) ago. Amhara Region has the highest prevalence of refractive errors among school students in Ethiopia with myopia being the most common type of refractive error.

Keywords

Prevalence refractive errors school students Ethiopia

Introduction

Refractive errors (REs) are conditions in which the optical system of the eye fails to focus parallel beams of light on the retina. As a result, the perceived picture is blurred, and refractive correction is necessary to see the image clearly.¹ Myopia, hyperopia, and astigmatism are the three types of REs.² Myopia was described as a spherical power of ⩽−0.50 diopter sphere in one eye or both eyes.^3,4 Hyperopia was described as a spherical power of ⩾+1.50 diopter sphere in one or both eyes.⁵ Astigmatism was defined as a cylindrical power of ⩾0.50 diopters in one or both eyes.^4,6 In myopia, light is focused to a position anterior to the retina due to excessive refraction either at the cornea, lens, or more typically an increased length of the eye.⁷ In hyperopia, the image is formed posterior to the retinal plane as a result of either insufficient refraction or a short axial length.⁸ In astigmatism, the refractive power of the eye is unequal across distinct meridians,⁹ resulting in blurred vision because the ocular system is unable to form a sharply focused image on the retina.¹⁰

REs are primary causes of visual impairment and secondary causes of blindness around the world.¹¹ For instance, myopia is a risk factor for ocular diseases such as glaucoma.¹² The global report on vision 2019 revealed that about 123.7 million people had visual impairment due to uncorrected REs, of which 12 million were children in the age group 5–15 years.¹³ REs, especially myopia, are most common visual problems among children and adolescents. It has a significant impact on children’s social and emotional well-being, which can limit their academic performance as well as access to education.^14,15 The consequences of undetected and untreated REs are severe particularly in school children, and affect their ability to read words and contents on the blackboard. They are also barred from productive working lives with serious economic and social implications in late adulthood life.¹⁶

Vision 2020 global initiative for elimination of avoidable blindness suggests visual acuity test in school health programs and provision of spectacles to all children with significant REs as a priority for national eye programs.¹⁷ A person who becomes blind as a result of REs at a young age and does not fix it would endure many more years of blindness than a person who becomes blind as a result of cataract in the old age. These impose huge socioeconomic burden on the individual and the society. Hence, the World Health Organization recommends frequent visual screening programs in school children.¹⁸

Ethiopia is one of the Africa’s least developed countries with relatively inadequate healthcare coverage, particularly in the area of eye health services, and is believed to have the highest rates of blindness.¹⁹ Many individuals continue to lose their sight because of lack of accessible and affordable primary eye care services. In Ethiopia, more than 85% of causes of low vision and blindness are either preventable or curable.¹⁹ According to the 2006 National Survey Report in Ethiopia, uncorrected REs caused 7.8% of blindness and 33.4% of low vision.²⁰

Many individual studies were conducted to assess the prevalence of REs among school students in different areas of Ethiopia: Gondar, 9.4%,⁴ Gurage Zone, 3.5%,²¹ Central Ethiopia, 6.3%,²² Debark and Kola Diba towns, 7.6%,²³ and Addis Ababa, 4.0%.²⁴ However, the magnitude of REs in those studies greatly varied. To the best of our knowledge, the pooled estimate of REs among school students in Ethiopia is not reported so far. Therefore, this systematic review and meta-analysis was conducted to estimate the pooled prevalence of REs among school students in Ethiopia. The findings of this review would help governmental and non-governmental organizations for evidence-based interventions like school-based visual screening and dissemination of free spectacles. It would also help policymakers and other concerned bodies to plan and campaign aimed at REs for elimination of avoidable and curable blindness.

Methods

Study design and setting

In September 2002, Ethiopia adopted vision 2020 global initiative to develop comprehensive and sustainable healthcare system. This initiative aimed to ensure best possible vision for all people with disease prevention, human power, and infrastructure development.^19,25 Thus, this systematic review and meta-analysis was conducted to estimate the pooled prevalence of REs among school students in Ethiopia. Ethiopia is one of the East African countries and is neighbored by Eritrea to the North, Djibouti and Somalia to the East, Sudan and South Sudan to the West, and Kenya to the South. It has ten regional states (Tigray, Afar, Amhara, Oromia, Somali, Benishangul-Gumuz, Southern Nations, Nationalities, and Peoples (SNNP), Sidama, Gambella, and Harari) and two city administrations (Addis Ababa and Dire Dawa).²⁶

Literature searching strategies

Searching strategies and protocols have been registered in PROSPERO for systematic review and meta-analysis with registration no. CRD42022296352. We have used the guideline for Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) to report searched articles.²⁷ International electronic databases (PubMed/Medline, Web of Science, Embase, Scopus, CINAHL, Google Scholar, Science Direct, and Cochrane Library) were searched to retrieve pertinent peer-reviewed articles. Reference lists of eligible studies were also intensively searched. In addition, we have searched official websites of local and international organizations (Addis Ababa University institutional repository and African journals online). The two authors (B.W.S. and G.S.) have searched and reviewed all retrieved articles independently using the PRISMA protocol. “Prevalence,” “refractive error,” “school students,” and “Ethiopia” were the key words for searching published articles in electronic databases (Supplemental additional file 1). “Medical subject heading (MeSH) terms,” “keywords,” and “Boolean operators” were used in separation and combination for searching the articles (Supplemental additional file 2).

Eligibility criteria

Inclusion criteria

The contents of each retrieved articles were thoroughly scrutinized by the two investigators (B.W.S. and G.S.) independently. Finally, only those literatures that met the following criteria were included in the study:

Population: studies done among school students.

Study design: all original articles reporting prevalence of REs and/or myopia, hyperopia, and astigmatism.

Study setting: only studies conducted in Ethiopia.

Language: only articles published and written in English language.

Publication status: all published articles and gray literatures that met the inclusion criteria.

Exclusion criteria

Articles reporting prevalence of REs and conducted at health facilities (clinics, health center, and hospitals) were excluded. Articles did not also report outcome of interest were also excluded.

Outcome of the study

The outcome of this study was to estimate the prevalence of REs including myopia, hyperopia, and astigmatism among school students in Ethiopia.

Data extraction and quality assessment

Microsoft Excel spreadsheet format was used to extract data. The extraction format consists of author/s name, year of publication, study region, study design, sample size, response rate, and prevalence of REs including myopia, hyperopia, and astigmatism. The two authors (B.W.S. and G.S.) independently extracted the data from 10 October 2021 to 1 January 2022. Quality of recruited articles was assessed using the Joanna Briggs Institute’s (JBI) critical appraisal checklist.²⁸ Methodological quality of the articles was also evaluated using modified version of Newcastle–Ottawa Scale (NOS) for cross-sectional studies.²⁹

Risk assessment of bias for the included studies

The 10 items rating scale was employed to assess risk of bias for the included studies. The studies were graded as having low risk of bias or “Yes” or high risk of bias or “No” answers to the domain questions. Items answered “Yes” had score “1” and “No” had score “0.” Thus, total item scores “8–10,” “6–7,” and “0–5” declared as having low risk of bias, moderate risk of bias, and high risk of bias, respectively.³⁰ Items 1–4 examine the study’s external validity (domains include selection and non-response bias), while items 5–10 assess the study’s internal validity (items 5–9 assess the domain of measurement bias, and item 10 assesses bias related to the analysis) (Supplemental additional file 3).

Statistical analysis

Microsoft Excel extracted data were exported to Stata version 14 statistical software for analysis. Cochrane’s Q statistics and inverse variance (I²) were employed to assess heterogeneity of the selected studies. Low, moderate, and high heterogeneity was quantified with I² test statistics for 25%, 50% and 75%, respectively.³¹ As a result of significant heterogeneity, random effect meta-analysis model was used to estimate the DerSimonian and Laird’s pooled effect. Egger’s and Begg’s tests were also used to assess publication bias.³² The pooled estimate with 95% confidence interval (CI) was presented using the Forest plot. The size of each box in the plot indicates the weight of the study while each crossed line indicates the CI. Regions and publication years were used for subgroup analysis. Meta-regression model was conducted to assess random variations among the selected studies. Sensitivity analysis was also performed to assess effect of a single study on the pooled estimate.

Results

Search results and study selection

A total of 10,577 articles were identified from electronic databases using MeSH terms, keywords, and Boolean operators in separation and combination. These articles were assessed, managed, and screened using their titles and abstracts through EndNote software. Due to duplications in the retrievals, 2222 of them were removed from inclusion. After reviewing the titles and abstracts, 8327 retrievals were excluded because they were unrelated to the outcome of interest in this meta-analysis. Then, 28 full-text articles were evaluated for eligibility using the eligibility criteria. Finally, 22 peer-reviewed articles were identified to be eligible for this systematic review and meta-analysis. However, six articles were not met the inclusion criteria and excluded with clear reasons^33–38 (Figure 1).

Figure 1.

PRISMA flowchart for refractive errors among school students in Ethiopia, 2021 (N = 22).

Characteristics of included articles

Twenty-two articles were recruited for this systematic review and meta-analysis. About 23,355 Ethiopian school students aged 5–24 years were involved in these studies. They were cross-sectional in design and published from 2002 to 2021. The largest (n = 4238) and smallest (n = 313) sample sizes were reported from studies done in Gurage Zone (SNNP region) and Gondar (Amhara Region), respectively.^22,39 Nine studies with 7438 participants were conducted in Amhara Region,^4,23,39–46 8 studies with 11,122 participants were done in SNNP,^{6,21,22,47–51} 1 study with 1137 participants was conducted in Tigray,⁵² and 4 studies with 3658 participants were done in Addis Ababa.^53–56 The included studies had the lowest response rate of 77% and the lowest quality score of 8 (Table 1).

Table 1.

Characteristics of included articles in this systematic review and meta-analysis of refractive errors among school students in Ethiopia, 2021 (N = 22).

Author name	Publication year	Region	Study site	Study design	Age group (years)	Sample size	Response rate (%)	Quality score (10 points)
Yared et al.⁴	2015	Amhara	Gondar	Cross-sectional	5–24	1722	93	9
Mehari and Yimer²²	2012	SNNP	Gurage Zone	Cross-sectional	7–18	4238	77	8
Sewunet et al.⁴²	2014	Amhara	Debre Markos	Cross-sectional	7–15	420	97	9
Kassa and Alene²³	2004	Amhara	Gondar	Cross-sectional	5–15	1112	98	9
Kedir and Girma²¹	2014	SNNP	Gurage Zone	Cross-sectional	7–15	570	96	9
Dhanesha et al.⁵²	2018	Tigray	Mekelle	Cross-sectional	11–15	1137	95	8
Hailu et al.⁵³	2019	Addis Ababa	Addis Ababa	Cross-sectional	7–17	773	95	8
Zelalem et al.⁴¹	2019	Amhara	Sekela Woreda	Cross-sectional	8–18	875	100	9
Woldeamanuel et al.⁴⁷	2020	SNNP	Gurage Zone	Cross-sectional	7–18	1064	100	9
Tegegne et al.⁴⁶	2021	Amhara	Bahir Dar	Cross-sectional	6–18	611	97	8
Alem and Gebru⁶	2021	SNNP	Hawassa	Cross-sectional	5–20	529	95	8
Ferede et al.⁴⁰	2020	Amhara	Gondar	Cross-sectional	5–15	1289	100	9
Gessesse and Teshome⁴⁸	2020	SNNP	Welkite	Cross-sectional	13–26	1271	89	8
Misganaw and Woldeyes⁵⁴	2014	Addis Ababa	Addis Ababa	Cross-sectional	5–18	1789	99	9
Assem et al.⁴⁴	2021	Amhara	Bahir Dar	Cross-sectional	6–18	601	95	8
Belete et al.⁴⁵	2016	Amhara	Gondar	Cross-sectional	15–22	495	99	9
Bezabih et al.⁵⁵	2016	Addis Ababa	Addis Ababa	Cross-sectional	6–18	718	89	8
Darge et al.⁵⁶	2017	Addis Ababa	Addis Ababa	Cross-sectional	5–16	378	100	9
Ezinne³⁹	2013	Amhara	Gondar	Cross-sectional	7–16	313	100	9
Abayo et al.⁴⁹	2021	SNNP	Kembata Zone	Cross-sectional	6–16	778	100	9
Worku and Bayu⁵⁰	2002	SNNP	Butajira	Cross-sectional	5–15	1846	95	9
Shaffi and Bejiga⁵¹	2005	SNNP	Goro district	Cross-sectional	6–15	826	100	9

SNNP: Southern Nations, Nationalities, and Peoples’ region.

The highest prevalence of RE (16.70, 95% CI = 13.74, 19.66) was reported in Bahir Dar, Amhara Region,⁴⁶ and the lowest prevalence of RE (2.50, 95% CI = 1.56, 3.44) was found in Gurage Zone, SNNP region.⁴⁷ The highest prevalence of myopia (11.90, 95% CI = 9.05, 14.75) and hyperopia (7.20, 95% CI = 5.15, 9.25) among school students was also revealed in Gondar and Bahir Dar, Amhara Region, respectively^45,46 (Table 2).

Table 2.

Prevalence of refractive error, myopia, hyperopia, and astigmatism of included articles for this systematic review and meta-analysis among school students in Ethiopia, 2021 (N = 22).

Author name	Refractive error (95% CI)	Sub types of refractive error
Author name	Refractive error (95% CI)	Myopia (95% CI)	Hyperopia (95% CI)	Astigmatism (95% CI)
Yared et al.⁴	10.10 (8.68, 11.52)	3.20 (2.37, 4.03)	2.70 (1.93, 3.47)	NR
Mehari and Yimer²²	6.30 (5.57, 7.03)	6.00 (5.28, 6.72)	0.30 (0.14, 0.46)	NR
Sewunet et al.⁴²	10.20 (7.31, 13.09)	5.50 (3.32, 7.68)	1.40 (0.28, 2.52)	0.02 (−0.11, 0.15)
Kassa and Alene²³	7.70 (6.13, 9.27)	7.60 (6.04, 9.16)	0.2 (−0.06, 0.46)	NR
Kedir and Girma²¹	3.50 (1.99, 5.01)	2.60 (1.29, 3.91)	0.90 (0.12, 1.68)	NR
Dhanesha et al.⁵²	11.00 (9.18, 12.82)	3.90 (2.77, 5.03)	0.40 (0.03, 0.77)	0.01 (−0.06, 0.09)
Hailu et al.⁵³	4.10 (2.70, 5.50)	1.90 (0.94, 2.86)	0.90 (0.23, 1.57)	0.01 (−0.07, 0.09)
Zelalem et al.⁴¹	3.80 (2.53, 5.07)	NR	NR	NR
Woldeamanuel et al.⁴⁷	2.50 (1.56, 3.44)	1.50 (0.77, 2.23)	0.50 (0.08, 0.92)	0.01 (−0.04, 0.05)
Tegenge et al.⁴⁶	16.70 (13.74, 19.66)	7.70 (5.59, 9.81)	7.20 (5.15, 9.25)	0.02 (−0.09, 0.12)
Alem and Gebru⁶	12.90 (10.04, 15.76)	9.80 (7.27, 12.33)	1.10 (0.21, 1.99)	0.02 (−0.10, 0.14)
Ferede et al.⁴⁰	3.90 (2.84, 4.96)	NR	NR	NR
Gessesse and Teshome⁴⁸	7.20 (5.78, 8.62)	6.50 (5.14, 7.86)	NR	NR
Misganaw and Woldeyes⁵⁴	3.90 (3.00, 4.80)	1.10 (0.62, 1.58)	0.30 (0.05, 0.55)	0.01 (−0.04, 0.07)
Assem et al.⁴⁴	8.50 (6.27, 10.73)	8.50 (6.27, 10.73)	NR	NR
Belete et al.⁴⁵	11.9 (9.05, 14.75)	11.90 (9.05, 14.75)	NR	NR
Bezabih et al.⁵⁵	3.6 (2.24, 4.96)	1.40 (0.54, 2.26)	0.4 (−0.06, 0.86)	0.02 (−0.08, 0.12)
Darge et al.⁵⁶	4.5 (2.41, 6.59)	NR	NR	NR
Ezinne³⁹	11.5 (7.97, 15.03)	6.10 (3.45, 8.75)	2.90 (1.04, 4.76)	0.03 (−0.15, 0.20)
Abayo et al.⁴⁹	4.8 (3.30, 6.30)	NR	NR	NR
Worku and Bayu⁵⁰	11.8 (10.33, 13.27)	NR	NR	NR
Shaffi and Bejiga⁵¹	6.3 (4.64, 7.96)	NR	NR	NR

NR: not reported; CI: confidence interval.

Pooled prevalence of REs among school students in Ethiopia

The overall pooled prevalence of REs was 7.36% (95% CI = 6.05, 8.67). Due to high heterogeneity (I² = 94.4%; p = 0.000), random model effect analysis was conducted considering this fact (Figure 2). The highest proportion of RE was found in Amhara Region (9.18%, 95% CI = 6.63, 11.74), followed by SNNP (6.78%, 95% CI = 4.65, 8.92) and Addis Ababa (3.93%, 95% CI = 3.30, 4.56). From a single multicenter study, 11% (95% CI = 9.18, 12.82) proportion of RE was reported in Tigray region (Figures 3 and 4). The prevalences of myopia and hyperopia were 5.10% (95% CI = 3.79, 6.40) and 0.95% (95% CI = 0.59, 1.31), respectively (Figures 5 and 6). The prevalence of astigmatism was 0.01% (95% CI = −0.01, 0.04).

Figure 2.

Pooled prevalence of refractive errors among school students in Ethiopia, 2021 (n = 22).

Figure 3.

The map illustrates the distribution of refractive error prevalences among school students in Ethiopian regions.⁵⁷

Figure 4.

Subgroup analysis of refractive errors by regions among school students in Ethiopia, 2021 (n = 22).

Figure 5.

Pooled prevalence of myopia among school students in Ethiopia, 2021 (n = 16).

Figure 6.

Pooled prevalence of hyperopia among school students in Ethiopia, 2021 (n = 13).

Publication bias and meta-regression

Funnel plot, Egger’s, and Begg’s tests were used to assess publication biases. The funnel plot showed asymmetrical distribution as subjectively shown (Figure 7). But, the Begg’s (p = 0.640) and Egger’s (p = 0.756) tests revealed no significant publication biases. Meta-regression analysis also revealed heterogeneity was not explained by sample sizes (p = 0.207), publication years (p = 0.374), and study regions (p = 0.238).

Figure 7.

Funnel plot of meta-analysis for refractive errors among school students in Ethiopia, 2021 (n = 22).

Discussion

REs are the most common ocular disorders among children and adolescents. They continue to be a secondary cause of avoidable blindness in impoverished areas throughout Africa, most notably in Ethiopia. The problem worsens if it is not discovered and addressed early in the young age population, particularly among children.¹³ In this study, the pooled prevalence of REs among school students in Ethiopia was 7.36%, of which myopia, hyperopia, and astigmatism accounted 5.1%, 0.95%, and 0.01%, respectively. The prevalence of REs in this study was in line with studies conducted in India, 8%,⁵⁸ Baltimore, 8.2%,⁵⁹ and Nepal, 8.6%.⁶⁰ However, our finding was lower than reported studies from Saudi Arabia, 16.8%,⁶¹ Japan, 10.4%,⁶² the United States, 18.2%,⁶³ and Uganda,12%.⁶⁴ The possible plausible explanation for the highest prevalence in the reported studies might be owing to increased educational demand which lead to greater near vision activities.⁶⁵ Nevertheless, the finding of the current review was higher than studies from Riyadh, 4.5%,⁶⁶ Iran, 3.8%,¹⁶ and Brazil, 4.82%.⁶⁷ The higher prevalence in this study might be due to lack of accessible and affordable primary eye care services in Ethiopia, or it might be due to REs that could be rectified with spectacles but have not been.

The prevalence of myopia in this study was comparable with previous studies in Africa, 4.7%,⁶⁸ the Middle East, 4%,⁶⁹ and India, 5.3%–7.5%.^58,70 But, our finding was lower than other studies in Norway, 35%,⁷¹ Colombia, 14.7%,⁷² China, 38.0%,⁷³ and Asia, 14.1%.⁷⁴ The higher prevalence in these studies could be due to myopia was more common in developed countries than developing countries. Myopia has historically been seen as an Asian health issue, with the prevalence being substantially greater in Asian societies than in Western communities.^75–77 This was supported by a reported study from India revealed myopia was more common in urban children than rural children.⁷⁸ This might be due to relatively increased literacy rate and duration of study hours of urban child than rural child. Myopia had also a direct relation with community development.⁷⁹ As a result, we believed that the increased frequency of myopia in developed countries was linked to rising literacy rates, educational expectations, and variations in lifestyle such as reading, watching TV, and computer visual display units. However, the correlation between myopia and close work remains obscure.⁸⁰

In this study, the prevalences of hyperopia and astigmatism were similar and comparable to studies conducted in India among rural school children (hyperopia = 0.39%, astigmatism = 0.21%),⁸¹ Vietnam (hyperopia = 0.4%, astigmatism = 0.7%),⁸² Thailand (astigmatism = 0.3%),⁸³ Malaysia (hyperopia = 1%, astigmatism = 0.6%),⁸⁴ and Pakistan (astigmatism = 0.76%).⁸⁵ However, our findings were lower than other study findings from Iran (hyperopia = 16.6%, astigmatism = 18.7%),¹⁶ Pakistan (myopia = 52.6%, astigmatism = 28.4%),⁸⁶ Jordan (hyperopia = 5.67%, astigmatism = 36.8%),⁸⁷ Turkey (astigmatism = 11%),⁸⁸ China (astigmatism = 40.8%),⁸⁹ and the Netherlands (hyperopia = 8%, myopia = 28%).⁹⁰ This discrepancies might be because of variations in geography, socioeconomic condition, race, and ethnicity. This was supported by a study which showed the Whites had the highest prevalence of hyperopia than the Hispanics, and African Americans had the lowest prevalence of astigmatism than Asian followed by Whites.⁹¹ This discrepancies could be also due to differences in study design (cycloplegia vs non-cycloplegia) or different definition of myopia, hyperopia, and astigmatism.

The subgroup analysis of this study also revealed that the prevalence of REs among school students significantly varies across different regions of Ethiopia. The highest prevalence was reported in Amhara Region followed by SNNP region. However, the lowest prevalence was reported in Addis Ababa. This regional discrepancy might be due to differences in the students’ physical activity, time spent outdoors, and near-work activity across those regions of Ethiopia.⁹² The other inherent regional variation could be attributed to access to government and private–owned primary eye care services including eye glasses and prescribed spectacles. This supports the lower prevalence reported in Addis Ababa, the capital city of Ethiopia, where primary eye care services and eye clinics are relatively available. This regional discrepancy suggests special campaign aimed REs among school students in Amhara and SNNP regions.

Limitations of the study

This systematic review and meta-analysis did not include all regional states of Ethiopia due to lack of published articles in those excluded regional states. In addition, this study did not assess predisposing factors of REs among school students in Ethiopia.

Conclusion

The pooled prevalence of REs among school students in Ethiopian was 7.36%. The prevalence of REs among Ethiopian school students is higher compared to what it was 5 years (7.05%) ago. The Amhara Region had the highest prevalence of REs among school students, followed by the SNNP region. Myopia was the most common RE among school students in Ethiopia.

Supplemental Material

sj-docx-1-smo-10.1177_20503121221127096 – Supplemental material for Prevalence of refractive errors among school students in Ethiopia: A systematic review and meta-analysis

Supplemental material, sj-docx-1-smo-10.1177_20503121221127096 for Prevalence of refractive errors among school students in Ethiopia: A systematic review and meta-analysis by Bickes Wube Sume and Girma Seyoum in SAGE Open Medicine

Supplemental Material

sj-docx-2-smo-10.1177_20503121221127096 – Supplemental material for Prevalence of refractive errors among school students in Ethiopia: A systematic review and meta-analysis

Supplemental material, sj-docx-2-smo-10.1177_20503121221127096 for Prevalence of refractive errors among school students in Ethiopia: A systematic review and meta-analysis by Bickes Wube Sume and Girma Seyoum in SAGE Open Medicine

Supplemental Material

sj-docx-3-smo-10.1177_20503121221127096 – Supplemental material for Prevalence of refractive errors among school students in Ethiopia: A systematic review and meta-analysis

Supplemental material, sj-docx-3-smo-10.1177_20503121221127096 for Prevalence of refractive errors among school students in Ethiopia: A systematic review and meta-analysis by Bickes Wube Sume and Girma Seyoum in SAGE Open Medicine

Footnotes

The authors gratefully thank the primary authors of included studies.

Author contributions

The two authors (B.W.S. and G.S.) participated equally in designing the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol,literature review,data extraction,and developing the manuscript. Both authors approved the final manuscript.

Availability of data and material

The data sets used for this systematic review and met-analysis are available from the corresponding author upon reasonable request.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research,authorship,and/or publication of this article.

Funding

The author(s) received no financial support for the research,authorship,and/or publication of this article.

ORCID iD

Bickes Wube Sume

Supplemental material

Supplemental material for this article is available online.

References

Jobke

Kasten

Vorwerk

The prevalence rates of refractive errors among children, adolescents, and adults in Germany. Clin Ophthalmol 2008; 2(3): 601–607.

Williams

Verhoeven

Cumberland

, et al. Prevalence of refractive error in Europe: the European Eye Epidemiology (E3) Consortium. Eur J Epidemiol 2015; 30(4): 305–315.

Mahjoob

Heydarian

Nejati

, et al. Prevalence of refractive errors among primary school children in a tropical area, Southeastern Iran. Asia Pac J Trop Biomed 2016; 6(2): 181–184.

Yared

Belaynew

Destaye

, et al. Prevalence of refractive errors among school children in Gondar town, northwest Ethiopia. Middle East Afr J Ophthalmol 2012; 19(4): 372–376.

Bakar

Chen

Noor

, et al. Comparison of refractive error and visual impairment between Native Iban and Malay in a formal government school vision loss prevention programme. Malays J Med Sci 2012; 19(2): 48–55.

Alem

Gebru

EA.

A cross-sectional analysis of refractive error prevalence and associated factors among elementary school children in Hawassa, Ethiopia. J Int Med Res 2021; 49(3): 1998894.

Saw

Seet

, et al. Academic achievement, close up work parameters, and myopia in Singapore military conscripts. Br J Ophthalmol 2001; 85(7): 855–860.

Robaei

Kifley

, et al. Prevalence of hyperopia and associations with eye findings in 6- and 12-year-olds. Ophthalmology 2008; 115(4): 678–685.

Shih

Hsiao

Tung

, et al. The prevalence of astigmatism in Taiwan schoolchildren. Optom Vis Sci 2004; 81(2): 94–98.

10.

Read

Collins

Carney

LG.

A review of astigmatism and its possible genesis. Clin Exp Optom 2007; 90(1): 5–19.

11.

World Health Organization. World report on vision, 2019, https://www.who.int/publications/i/item/9789241516570

12.

Biswas

Jhanji

Leung

CK.

Prevalence of glaucoma in myopic corneal refractive surgery candidates in Hong Kong China. J Refract Surg 2016; 32(5): 298–304.

13.

Pascolini

Mariotti

SP.

Global estimates of visual impairment: 2010. Brit J Ophthalmol 2012; 96(5): 614–618.

14.

Packwood

Cruz

Rychwalski

, et al. The psychosocial effects of amblyopia study. J AAPOS 1999; 3(1): 15–17.

15.

Naidoo

Jaggernath

Uncorrected refractive errors. Indian J Ophthalmol 2012; 60(5): 432–437.

16.

Fotouhi

Hashemi

Khabazkhoob

, et al. The prevalence of refractive errors among schoolchildren in Dezful, Iran. Brit J Ophthalmol 2007; 91(3): 287–292.

17.

World Health Organization. Global initiative for the elimination of avoidable blindness. Geneva: World Health Organization, 2000.

18.

Dandona

Refractive error blindness. Bullet World Health Organ 2001; 79: 237–243.

19.

Berhane

Worku

Bejiga

, et al. National survey on blindness, low vision and trachoma in Ethiopia: methods and study clusters profile. Ethiop J Health Develop 2007; 21(3): 185–203.

20.

Berhane

Worku

Bejiga

National survey on blindness, low vision and trachoma in Ethiopia. Addis Ababa, Ethiopia: Federal Ministry of Health of Ethiopia, 2006, p. 9.

21.

Kedir

Girma

Prevalence of refractive error and visual impairment among rural school-age children of Goro District, Gurage Zone, Ethiopia. Ethiop J Health Sci 2014; 24(4): 353–358.

22.

Mehari

Yimer

AW.

Prevalence of refractive errors among schoolchildren in rural central Ethiopia. Clin Exp Optom 2013; 96(1): 65–69.

23.

Kassa

Alene

GD.

Prevalence of refractive errors in pre-school and school children of Debark and Kola Diba towns, North-western Ethiopia. Ethiop J Health Develop 2003; 17(2): 117–124.

24.

Nebiyat

Alemayehu

Tigist

Refractive errors among school children in Addis Ababa, Ethiopia. J Ophthalmol East Cent South Afr 2015; 19(2): 57–62.

25.

Berhane

Worku

Bejiga

, et al. Prevalence and causes of blindness and low vision in Ethiopia. Ethiop J Health Develop 2007; 21(3): 204–210.

26.

Okumu

Resources and border disputes in Eastern Africa. J East Afr Stud 2010; 4(2): 279–297.

27.

Liberati

Altman

Tetzlaff

, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 2009; 62(10): e1–e34.

28.

Munn

Moola

Riitano

, et al. The development of a critical appraisal tool for use in systematic reviews addressing questions of prevalence. Int J Health Policy Manage 2014; 3(3): 123–128.

29.

Moskalewicz

Oremus

No clear choice between Newcastle–Ottawa Scale and Appraisal Tool for Cross-Sectional Studies to assess methodological quality in cross-sectional studies of health-related quality of life and breast cancer. J Clin Epidemiol 2020; 120: 94–103.

30.

Hoy

Brooks

Woolf

, et al. Assessing risk of bias in prevalence studies: modification of an existing tool and evidence of interrater agreement. J Clin Epidemiol 2012; 65(9): 934–939.

31.

Rücker

Schwarzer

Carpenter

, et al. Undue reliance on I² in assessing heterogeneity may mislead. BMC Med Res Methodol 2008; 8(1): 1–9.

32.

Borenstein

Hedges

Higgins

, et al. A basic introduction to fixed-effect and random-effects models for meta-analysis. Res Synth Methods 2010; 1(2): 97–111.

33.

Getnet

Akalu

Dagnew

, et al. Visual impairment and its associated factors among medical and health sciences students at the University of Gondar, Northwest Ethiopia. PLoS ONE 2021; 16(8): e0255369.

34.

Mehari

ZA.

Pattern of childhood ocular morbidity in rural eye hospital, central Ethiopia. BMC Ophthalmol 2014; 14(1): 1–6.

35.

Kello

Gilbert

Causes of severe visual impairment and blindness in children in schools for the blind in Ethiopia. Br J Ophthalmol 2003; 87(5): 526–530.

36.

Demissie

Solomon

AW.

Magnitude and causes of childhood blindness and severe visual impairment in Sekoru District, Southwest Ethiopia: a survey using the key informant method. Trans R Soc Trop Med Hyg 2011; 105(9): 507–511.

37.

Abebe

Wagnew

Zeleke

, et al. Magnitude of visual impairment and associated factors among patients attending ophthalmic clinics of Debre Markos referral hospital, North West Ethiopia. BMC Ophthalmol 2021; 21(1): 1–10.

38.

Demissie

ES.

Patterns of eye diseases in children visiting a tertiary teaching hospital: South-western Ethiopia. Ethiop J Health Sci 2014; 24(1): 69–74.

39.

Ezinne

Prevalence of refractive error among school children in Meseret General Primary School Gondar Town North West Ethiopia. J Health Vis Sci 2013; 15(1): 23–29.

40.

Ferede

Alemu

Gudeta

, et al. Visual impairment among primary school children in Gondar Town, Northwest Ethiopia. J Ophthalmol 2020; 2020: 6934013.

41.

Zelalem

Abebe

Adamu

, et al. Prevalence of visual impairment among school children in three primary schools of Sekela Woreda, Amhara regional state, north-west Ethiopia. SAGE Open Med 2019; 7: 9849769.

42.

Sewunet

Aredo

Gedefew

Uncorrected refractive error and associated factors among primary school children in Debre Markos District, Northwest Ethiopia. BMC Ophthalmol 2014; 14(1): 1–6.

43.

Merrie

Tegegne

Munaw

, et al. Prevalence and associated factors of visual impairment among school-age children in Bahir Dar City, Northwest Ethiopia. Clin Optom 2019; 11: 135–143.

44.

Assem

Tegegne

Fekadu

SA.

Prevalence and associated factors of myopia among school children in Bahir Dar city, Northwest Ethiopia, 2019. PLoS ONE 2021; 16(3): e0248936.

45.

Belete

Anbesse

Tsegaye

, et al. Prevalence and associated factors of myopia among high school students in Gondar town, northwest Ethiopia, 2016. Clin Optom 2017; 9: 11–18.

46.

Tegegne

Fekadu

Assem

AS.

Prevalence of strabismus and its associated factors among school-age children living in Bahir Dar city: a community-based cross-sectional study. Clin Optom 2021; 13: 103–112.

47.

Woldeamanuel

Biru

Geta

, et al. Visual impairment and associated factors among primary school children in Gurage Zone, Southern Ethiopia. Afr Health Sci 2020; 20(1): 533–542.

48.

Gessesse

Teshome

AW.

Prevalence of myopia among secondary school students in Welkite town: South-Western Ethiopia. BMC Ophthalmol 2020; 20(1): 1–6.

49.

Abayo

Gessesse

Asaminew

Prevalence and pattern of ocular morbidity among school children in southern Ethiopia. Ethiop J Health Sci 2021; 31(4): 831–836.

50.

Worku

Bayu

Screening for ocular abnormalities and subnormal vision in school children of Butajira Town, southern Ethiopia. Ethiop J Health Develop 2002; 16(2): 165–171.

51.

Shaffi

Bejiga

Common eye diseases in children of rural community in Goro district, central Ethiopia. Ethiop J Health Develop 2005; 19(2): 148–152.

52.

Dhanesha

Polack

Bastawrous

, et al. Prevalence and causes of visual impairment among schoolchildren in Mekelle, Ethiopia. Cogent Med 2018; 5(1): 1554832.

53.

Hailu

Hiko

Shaweno

Prevalence of visual impairment and associated factors among primary schoolchildren in Addis Ababa, central Ethiopia. Clin Ophthalmol 2020; 14: 767–774.

54.

Misganaw

Woldeyes

Prevalence and factors associated with refractive error among primary school children in Addis Ababa, Ethiopia. Int J Med Health Sci Res 2014; 1(9): 92–104.

55.

Bezabih

Abebe

Fite

RO.

Prevalence and factors associated with childhood visual impairment in Ethiopia. Clin Ophthalmol 2017; 11: 1941–1948.

56.

Darge

Shibru

Mulugeta

, et al. The prevalence of visual acuity impairment among school children at Arada Subcity primary schools in Addis Ababa, Ethiopia. J Ophthalmol 2017; 2017: 9326108.

57.

Regions of Ethiopia, 1992, https://en.wikipedia.org/wiki/Regions_of_Ethiopia

58.

Sheeladevi

Seelam

Nukella

, et al. Prevalence of refractive errors in children in India: a systematic review. Clin Exp Optom 2018; 101(4): 495–503.

59.

Preslan

Novak

Baltimore vision screening project. Ophthalmology 1996; 103(1): 105–109.

60.

Shrestha

Sujakhu

Joshi

Refractive error among school children in Jhapa, Nepal. J Optom 2011; 4(2): 49–55.

61.

Alghamdi

Prevalence of refractive errors among children in Saudi Arabia: a systemic review. Open Ophthalmol J 2021; 15(1): 89–95.

62.

Kazuhiro

Refractive errors among Japanese school children XXIII Cong. Ophthalmology 1978; 25: 1207–1211.

63.

Chen

Chang

Lee

, et al. Prevalence of ocular disorders among 6- and 7-year-olds in Santa Monica, California. J Am Optom Assoc 1996; 67(6): 358–365.

64.

Kawuma

Mayeku

A survey of the prevalence of refractive errors among children in lower primary schools in Kampala district. Afr Health Sci 2002; 2(2): 69–72.

65.

Saxena

Vashist

Tandon

, et al. Prevalence of myopia and its risk factors in urban school children in Delhi: the North India Myopia Study (NIM Study). PLoS ONE 2015; 10(2): e0117349.

66.

Al-Rowaily

MA.

Prevalence of refractive errors among pre-school children at King Abdulaziz Medical City, Riyadh, Saudi Arabia. Saudi J Ophthalmol 2010; 24(2): 45–48.

67.

Salomão

Mitsuhiro

Belfort

Jr.

Visual impairment and blindness: an overview of prevalence and causes in Brazil. An Acad Bras Cienc 2009; 81(3): 539–549.

68.

Ovenseri-Ogbomo

Osuagwu

Ekpenyong

, et al. Systematic review and meta-analysis of myopia prevalence in African school children. PLoS ONE 2022; 17(2): e0263335.

69.

Khoshhal

Hashemi

Hooshmand

, et al. The prevalence of refractive errors in the Middle East: a systematic review and meta-analysis. Int J Ophthalmol 2020; 40(6): 1571–1586.

70.

Agarwal

Saxena

Gupta

, et al. Prevalence of myopia in Indian school children: meta-analysis of last four decades. PLoS ONE 2020; 15(10): e0240750.

71.

Midelfart

Kinge

Midelfart

, et al. Prevalence of refractive errors in young and middle-aged adults in Norway. Acta Ophthalmol Scand 2002; 80(5): 501–505.

72.

Galvis

Tello

Otero

, et al. Prevalence of refractive errors in Colombia: MIOPUR study. Br J Ophthalmol 2018; 102(10): 1320–1323.

73.

Tang

Chen

Zou

, et al. Prevalence and time trends of refractive error in Chinese children: a systematic review and meta-analysis. J Glob Health 2021; 11: 08006.

74.

Pan

Dirani

Cheng

, et al. The age-specific prevalence of myopia in Asia: a meta-analysis. Optom Vis Sci 2015; 92(3): 258–266.

75.

Hyman

Myopic and hyperopic refractive error in adults: an overview. Ophthalmic Epidemiol 2007; 14(4): 192–197.

76.

Saw

SM.

A synopsis of the prevalence rates and environmental risk factors for myopia. Clin Exp Optom 2003; 86(5): 289–294.

77.

Saw

Katz

Schein

, et al. Epidemiology of myopia. Epidemiol Rev 1996; 18(2): 175–187.

78.

Uzma

Kumar

Khaja Mohinuddin Salar

, et al. A comparative clinical survey of the prevalence of refractive errors and eye diseases in urban and rural school children. Can J Ophthalmol 2009; 44(3): 328–333.

79.

Zeng

Liu

, et al. Refractive error and visual impairment in urban children in southern China. Invest Ophthalmol Vis Sci 2004; 45(3): 793–799.

80.

Ramamurthy

Lin Chua

Saw

SM.

A review of environmental risk factors for myopia during early life, childhood and adolescence. Clin Exp Optom 2015; 98(6): 497–506.

81.

Padhye

Khandekar

Dharmadhikari

, et al. Prevalence of uncorrected refractive error and other eye problems among urban and rural school children. Middle East Afr J Ophthalmol 2009; 16(2): 69–74.

82.

Paudel

Ramson

Naduvilath

, et al. Prevalence of vision impairment and refractive error in school children in Ba Ria–Vung Tau province, Vietnam. Clin Exp Ophthalmol 2014; 42(3): 217–226.

83.

Yingyong

Refractive errors survey in primary school children (6-12 year old) in 2 provinces: Bangkok and Nakhonpathom (one year result). J Med Assoc Thai 2010; 93(10): 1205–1210.

84.

Hashim

Tan

Wan-Hazabbah

, et al. Prevalence of refractive error in Malay primary school children in suburban area of Kota Bharu, Kelantan, Malaysia. Ann Acad Med Singap 2008; 37(11): 940–946.

85.

Gull

Visual screening and refractive errors among school aged children. J Rawalp Med Coll 2014; 18(1): 97–100.

86.

Atta

Arif

Ahmed

, et al. Prevalence of refractive errors in Madrassa students of Haripur district. J Ayub Med Coll Abbottabad 2015; 27(4): 850–852.

87.

Mallen

Gammoh

Al-Bdour

, et al. Refractive error and ocular biometry in Jordanian adults. Ophthalmic Physiol Opt 2005; 25(4): 302–309.

88.

Gursoy

Basmak

Yaz

, et al. Vision screening in children entering school: Eskisehir, Turkey. Ophthalmic Epidemiol 2013; 20(4): 232–238.

89.

Sun

Cao

Yan

ZG.

Prevalence of refractive errors in middle school students in Lanzhou city. Int J Ophthalmol 2007; 7(5): 1240–1242.

90.

Hendricks

de Brabander

Vankan-Hendricks

, et al. Prevalence of habitual refractive errors and anisometropia among Dutch schoolchildren and hospital employees. Acta Ophthalmol 2009; 87(5): 538–543.

91.

Kleinstein

Jones

Hullett

, et al. Refractive error and ethnicity in children. Arch Ophthalmol 2003; 121(8): 1141–1147.

92.

Karthikeyan

Ashwini

Priyanka

, et al. Physical activity, time spent outdoors, and near work in relation to myopia prevalence, incidence, and progression: an overview of systematic reviews and meta-analyses. Indian J Ophthalmol 2022; 70(3): 728–739.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.01 MB

0.00 MB

0.01 MB