Myopia in Children and Adolescents Linked to Screen Time

Researchers conducted a comprehensive analysis and quantitative evaluation of the epidemiological evidence regarding the relationship between screen time exposure and myopia in children and adolescents in a new study that was published in the BMC Public Health.

Context

The refractive error known as myopia, or near-sightedness, is characterized by an abnormal elongation of the ocular globe. This condition increases the risk of pathological changes in the eyes, including macular degeneration, cataracts, glaucoma, and retinal detachment, all of which can result in irreversible vision loss.

Outdoor activities, near-work, and education are examples of environmental factors that have a substantial impact on the prevalence of myopia. These days, children’s and teenagers’ lives are dominated by screen time, which includes using computers, televisions, video games, and mobile devices. Exposure to screen time increases with age.

There is inconsistent evidence in recent epidemiological studies about the relationship between screen usage and myopia.

To make sense of the contradictory results regarding the link between screen time and myopia in kids and teenagers, as well as to develop practical preventative and management techniques, more research is required.

Concerning the study

In this systematic review and meta-analysis, researchers conducted literature screening, data extraction, risk of bias assessment, and analysis.

Eligibility criteria included studies on children and adolescents examining screen time exposure (categorical or continuous) and reporting adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for myopia, by the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) 2020 statement.

If many studies reported on the same population, the most recent and thorough publication was chosen to include observational studies utilizing cross-sectional, cohort, or case-control designs.

Screen- and myopia-related terms were utilized in PubMed, Embase, and Web of Science literature searches through June 1, 2023. Reviews, letters, commentary, research on occupational exposure, studies involving non-human subjects, studies on ecology, and studies without effect estimates were among the materials excluded.

Author information, publication year, nation, sample size, screen device type, myopia definition, results (ORs and 95%CIs), and confounder adjustments were among the data extracted. The Newcastle Ottawa Scale (NOS), which rates studies as high, moderate, or poor quality, was utilized for the quality assessment.

R software was used for the statistical analysis, which made use of heterogeneity-based fixed-effect or random-effect models. Subgroup and sensitivity analyses were performed, and funnel plots, Egger’s test, and the trim and fill method were used to assess publication bias.

Study findings

6,493 publications were found for the study using Web of Science, Embase, and PubMed. During the title and abstract screening, 5,295 irrelevant research were eliminated after 1,159 duplicate studies were eliminated.

Twenty publications were eliminated after thirty-nine were evaluated for eligibility because of univariate analysis, absence of data, or low prevalence of myopia.

In the end, 102,360 participants from 19 studies were selected; 91,282 were from cross-sectional studies (N = 15), and 11,078 from cohort studies (N = 4).

 Thirteen studies (68%) used cycloplegic refraction, three (16%) used self-reported myopia, and three (16%) performed optometry without cycloplegia. The studies originated from nine countries: two from North America, seven from Europe, six from East Asia, two from South Asia, and two from Southeast Asia. According to the NOS checklist, 14 studies (74%) were considered high quality (score ≥ seven stars), while the remaining five studies (26%) were of moderate quality (score 5 or 6 stars). Possible sources of bias included small sample sizes in six studies, insufficient strategies to deal with confounding factors in five studies, lack of adjustment for key confounders in five studies, and not using cycloplegic refraction to confirm myopia cases in five studies.

The association between category screen time exposure (high vs. low) and myopia in children and adolescents was investigated in eleven studies with a total of 90,415 individuals. In both cohort studies (OR=2.39, 95%CI: 2.07–2.79) and cross-sectional studies (OR=2.24, 95%CI: 1.47–3.42), the highest category of screen time exposure was substantially linked to myopia.

Smartphones did not exhibit significant links with myopia, whereas PCs and televisions did, according to subgroup analysis by screen device type. Significant connections were found in high-quality studies, in East and South Asia, and research conducted after 2008 when subgroup analysis was performed based on study quality, geographic region, and research time.

Myopia and continuous exposure (per 1 h/d increase) to screen time were examined in eight trials with 11,925 participants. Cohort studies revealed a significant connection (OR=1.07, 95%CI: 1.01–1.13), but cross-sectional studies found no association (OR=1.15, 95%CI: 0.97–1.37).

Prominent correlations were observed regarding computer screen usage in East Asian and cross-sectional research. For cohort studies, additional subgroup analyses were not carried out because of the small number of studies.

Egger’s test revealed publication bias in cross-sectional research for both high vs. low screen time and per 1 h/d increasing screen time groups. Following a study of trim and fill, the pooled odds ratios held significance.

Sensitivity analysis revealed strong results for the groups with high and low screen times, but not for the group with screen times increased by one hour per day.

In conclusion

In conclusion, our thorough meta-analysis discovered a strong correlation between myopia and screen time spent on computers and televisions, but not on smartphones. There were observed regional variations, with notable correlations seen in East and South Asia.

The study underlined the necessity of focused preventative measures, such as lowering activities conducted close to the workplace and encouraging outdoor recreation. 

For more information: The association between screen time exposure and myopia in children and adolescents: a meta-analysis, BMC Public Health, https://doi.org/10.1186/s12889-024-19113-5