Abstract
Purpose :
To evaluate the Diabetic Retinopathy (DR) prevalence and incidence in different sampling sites from 2000 to 2017, methodological defects, and results of studies in Iran using a Systematic Review, and Meta-Analysis
Methods :
The electronic databases PubMed, Embase, Scopus, ISI web of knowledge, Google Scholar, and local databases were searched for cohort and cross-sectional studies up to January 2018. Prevalence and incidence of DR were extracted, and random effects models were used to estimate pooled effect sizes. Important variables regarding DR studies were provided to evaluate the reporting of results. The Joanna Briggs Institute critical appraisal tool was applied for quality assessments of eligible studies.
Results :
A total of 55445 participants from 33 studies were included. Pooled prevalence and incidence rate (per 100 person-years) of DR were 33.6% (95% CI: 27.9, 39.2) and 11.7% (95% CI: 8.0, 15.9) among diabetics. It was 31.8 (95% CI: 24.5, 39.2), 44.5 (95% CI: 31.3, 57.6), and 29.6 (95% CI: 22.6, 36.5) in DM (diabetes) clinics, eye clinic, and population-based studies, respectively. The PDR: NPDR (proliferative diabetic retinopathy: non proliferative diabetic retinopathy) ratio was 13.8% in DM clinics vs. 67% in eye clinics. Only 33.3% (n=11) of studies reported their DR results by gender. Total of 42.4% (n=14) studies reported types of DR. About 54.54% (n=18) of studies clearly stated performing indirect ophthalmoscopy with pupillary dilation for evaluation of DR.
Conclusions :
There were great discrepancies in prevalence among different sampling sites. The most reliable evidence on DR prevalence was likely to be retrieved from DM clinics due to its similarity to population based studies. The difference in PDR: NPDR ratio in DM and eye clinics showed inappropriate screening, leading to advanced stages of DR. Providing a list of essential items for reporting the descriptive epidemiology of DR in studies is a necessity. Although our findings on the prevalence, incidence, and methodological issues regarding DR may not be generalizable to all countries, it could be useful for developing countries, especially areas with similar socioeconomic, demographic, and geographic conditions.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.