Moderate hyperopia prevalence and associated factors among elementary school students

Early Detection of Refractive Errors by Photorefraction at School Age

Early detection and treatment of refractive defects during school age are essential to avoid irreversible future vision loss and potential school problems. Previously, vision screening of preschool children used methods based on subjective visual acuity; however, technologies such as photorefraction have promoted the detection of refractive errors quickly and easily. In this study, 1347 children from 10 schools in Madrid aged 4 to 12 years participated in a program of early detection of visual problems, which consisted of visual screening composed of anamnesis and photorefraction with a PlusOptix A12R. The prevalence of refractive errors was analyzed in terms of spherical equivalent, cylinder and its orientation, and potential cases of development of high myopia or amblyopia. Hyperopia predominates in the early years, but the number of myopic subjects is higher than that of hyperopic subjects from the age of ten onwards. At all ages, the predominant orientation of astigmatism was with-the-rule. On average, 80% of the myopic subjects were uncorrected. Potential high myopia increased with age, from 4 to 21% of the measured population. Potential amblyopia cases decreased across age groups, from 19 to 13.7%. There is a need to raise awareness of the importance of vision screening at school age to address vision problems.

Refractive Error of Students (15- to 18-year-olds) in Northwest Mexico

SIGNIFICANCE

We assessed the prevalence of refractive error in a sample of children of Northern Mexico using the Refractive Error Study in Children protocol of the World Health Organization, which allows for the comparison with other global studies.

PURPOSE

Uncorrected refractive error is the main cause of visual impairment in children. The purpose of this study was to assess the refractive error and visual dysfunctions of students (15 to 18 years old) in the upper-middle school system of Sinaloa, Mexico.

METHODS

A total of 3468 students in Sinaloa's high school system participated in the study from 2017 to 2019. Optometrists and student clinicians from the Optometry Program of the Autonomous University of Sinaloa conducted the testing. Tests included visual acuities and static retinoscopy. We did not use a cycloplegic agent.

RESULTS

The results showed a high prevalence of uncorrected refractive errors. Myopia, defined as a refractive error ≤-0.50 D, had a prevalence of 36.11% (95% confidence interval, 33.47 to 38.83%); hyperopia, defined as a refractive error ≥+2.00 D, had a prevalence of 1.49% (95% confidence interval, 0.09 to 2.33%); and astigmatism, defined as a refractive error with a cylinder ≥0.75 D, had a prevalence of 29.17% (95% confidence interval, 26.60 to 31.76%). We found a significant effect of sex on visual acuity.

CONCLUSIONS

Our results are consistent with a high prevalence of myopia reported in adolescents worldwide and in Mexico's northern regions. The results suggest that students attending high school and entering universities should be required to have an optometric eye examination. Additional studies are needed to investigate the prevalence of refractive errors in children in Mexico.

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

Purpose

The aim of the study was a systematic review of refractive errors across the world according to the WHO regions.

Methods

To 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).

Results

In 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).

Conclusion

This 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.