Diabetic retinopathy in Ethiopia: a systematic review and meta-analysis

Authors: Fite RO, Lake EA, Hanfore LK.

Geographical coverage: Ethiopia

Sector: Burden of disease

Sub-sector: Epidemiology, prevalence

Equity focus: Not reported

Study population: Patients with diabetic retinopathy

Review type: Other review

Quantitative synthesis method: Meta-analysis

Qualitative synthesis method: Not applicable

Background: Diabetes mellitus (DM) is related to hyperglycaemia, which contributes to micro- and macro-vascular including multiple visual complications. Diabetic retinopathy (DR) affects the retina of the eye, but does not exhibit any symptoms in many patients. The annual incidence of DR varies worldwide but is consistently increasing. Prevention strategies will be helpful to prevent progression to complications.

Objectives: This review aimed to determine the prevalence of DR among patients with DM in Ethiopia.

Main findings: A total of 502 articles were identified from the electronic database searches, of which 16 were included in this meta-analysis. None of the 16 included studies had a considerable risk. The prevalence of DR varied from region to region in Ethiopia. The overall prevalence of retinopathy was 19.48% (95% CI: 15.95, 23.01; I² = 90.6%). The highest prevalence of retinopathy (33.8%) was in the Oromia region and the lowest (4.7%) was in Addis Ababa. Sensitivity analysis indicated the impact of two studies. Region-based subgroup analysis found the following prevalence of DR:12.48% in Southern Nations and Nationalities Peoples’ region, 24.8% in Oromia, 19.99% in Amhara and 16.29% in Addis Ababa.

The findings of this showed that the overall prevalence of DR among patients with DM was high in Ethiopia (19.48% [95% CI: 15.95, 23.01]). The authors emphasised that early detection of poorly controlled DM and close monitoring of bad patient progress is essential to prevent DR. In addition, the authors recommended a national level study to diagnose DR using ophthalmoscope or fluorescein angiography diagnosis.

Methodology: Searches were conducted in PubMed, EMBASE, Science Direct and Google Scholar to identify observational studies reporting the prevalence of DR in Ethiopia. Searches were restricted to articles published in the English language. The authors of the original study were contacted for missing data.

Three reviewers independently conducted abstract and full-text screening, and quality assessment of the included studies. Two reviewers conducted data extraction independently. The results were synthesised via meta-analysis using a weighted inverse variance random-effects model. The reviewers appraised the quality of the included studies using the Joanna Briggs Institute (JBI) quality appraisal checklist. Heterogeneity was assessed using I² statistics. Subgroup analysis was conducted by region. Sensitivity analysis was conducted to evaluate the effect of single study on the overall estimation. Publication bias was assessed using the funnel plot and Egger’s regression test.

Applicability/external validity: The review did not discuss the applicability or external validity of the results.

Geographic focus:

The study focused on the prevalence of DR in Ethiopia.

Summary of quality assessment:

The conclusions of this review are regarded with low confidence due to the identified shortcomings in the review methodology. The literature search was confined to peer-reviewed articles written solely in English. Furthermore, studies with different levels of bias were not individually reported and analysed based on their bias status.