Global and regional estimates of prevalence of refractive errors: Systematic review and meta-analysis

Abstract

PurposeThe aim of the study was a systematic review of refractive errors across the world according to the WHO regions.MethodsTo extract articles on the prevalence of refractive errors for this meta-analysis, international databases were searched from 1990 to 2016. The results of the retrieved studies were merged using a random effect model and reported as estimated pool prevalence (EPP) with 95% confidence interval (CI).ResultsIn children, the EPP of myopia, hyperopia, and astigmatism was 11.7% (95% CI: 10.5–13.0), 4.6% (95% CI: 3.9–5.2), and 14.9% (95% CI: 12.7–17.1), respectively. The EPP of myopia ranged from 4.9% (95% CI: 1.6–8.1) in South–East Asia to 18.2% (95% CI: 10.9–25.5) in the Western Pacific region, the EPP of hyperopia ranged from 2.2% (95% CI: 1.2–3.3) in South-East Asia to 14.3% (95% CI: 13.4–15.2) in the Americas, and the EPP of astigmatism ranged from 9.8% in South-East Asia to 27.2% in the Americas. In adults, the EPP of myopia, hyperopia, and astigmatism was 26.5% (95% CI: 23.4–29.6), 30.9% (95% CI: 26.2–35.6), and 40.4% (95% CI: 34.3–46.6), respectively. The EPP of myopia ranged from 16.2% (95% CI: 15.6–16.8) in the Americas to 32.9% (95% CI: 25.1–40.7) in South-East Asia, the EPP of hyperopia ranged from 23.1% (95% CI: 6.1%–40.2%) in Europe to 38.6% (95% CI: 22.4–54.8) in Africa and 37.2% (95% CI: 25.3–49) in the Americas, and the EPP of astigmatism ranged from 11.4% (95% CI: 2.1–20.7) in Africa to 45.6% (95% CI: 44.1–47.1) in the Americas and 44.8% (95% CI: 36.6–53.1) in South-East Asia. The results of meta-regression showed that the prevalence of myopia increased from 1993 (10.4%) to 2016 (34.2%) (P = 0.097).ConclusionThis report showed that astigmatism was the most common refractive errors in children and adults followed by hyperopia and myopia. The highest prevalence of myopia and astigmatism was seen in South-East Asian adults. The highest prevalence of hyperopia in children and adults was seen in the Americas.

Evaluation of vision screening of 5–15‐year‐old children in three Tongan schools: comparison of The Auckland Optotypes and Lea symbols

“…Comparison of these results to epidemiological work is challenging given: (1) the small sample; (2) the use of the non‐cycloplegic Spot Photoscreener as an estimate of refraction; and (3) the difference between cut‐offs used in epidemiological work compared to that used for clinical referral . With these caveats in mind, the refraction data suggest that Tongan school children experience lower levels of myopia than children from developed parts of South East Asia, with our results being more in line with the rates of myopia reported in other Pacific Islands .…”

“…While the data suggested low rates of myopia, there appeared to be higher levels of mild astigmatism compared to international norms . It has been reported that astigmatism is associated with keratoconus, and that Pacific students in New Zealand high schools have higher rates of keratoconus than their European peers .…”

Screening of refractive error among primary school students at Tanta City Gharbia governorate Egypt. How serious is the problem?

“…11 On the other hand, our finding agrees with Hashemi H (2017) finding in systematic review and meta-analysis that astigmatism was the most common refractive error in children. 12 This variation can be explained by using different methods in the evaluation of RE type. In the present study, we used the (Plusoptix A12 R USA manufactured tool) photorefractory device which gives an accurate evaluation of RE and better detection of astigmatism than retinoscopy Study limitation is the unequal number of boys and girls; girls had a higher participation rate both in governmental and non-governmental school.…”

Imaging in myopia: potential biomarkers, current challenges and future developments

“…Usually stratification is required for covariates that affect measurements such as age, ethnicity and refractive error. For myopia, this is a challenge because of the large regional variation in refractive error prevalence 22. As such the normative database in OCT systems will not optimally reflect the patient population in regions where myopia and PM are highly prevalent, such as in East Asia.…”