How genetic is school myopia?
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing genetic, twin, and epidemiological literature
PubMed 15555525 · doi:10.1016/j.preteyeres.2004.06.004
What was done
This narrative review synthesized evidence on the genetic and environmental determinants of school myopia. It evaluated known chromosomal localizations for high familial myopia, refractive error correlations in families and twins, parent-offspring heritability across rapidly developing generations, and epidemiological prevalence patterns across urban, rural, and ethnically diverse populations.
What was found
The abstract provides qualitative findings without specific numerical values. Chromosomal loci linked to high familial myopia do not appear relevant to common school myopia. While twin studies report high heritability, parent-offspring correlations yield low heritability when rapid environmental changes occur between generations. Marked increases in myopia prevalence correspond with increased schooling and urbanization across diverse ancestral groups. Furthermore, East Asian populations exhibit very low myopia prevalence in rural settings, while Indian populations in Singapore exhibit high prevalence, indicating that high myopia propensity is a shared human response to myopigenic environments rather than an intrinsic population-specific genetic trait.
Why it matters
This paper reframes school myopia primarily as an environmentally driven condition shaped by schooling and urbanization rather than an unmodifiable genetic trait. It demonstrates that high twin-based heritability estimates do not preclude large-scale environmental interventions.
Limits
As a narrative review, the paper lacks systematic search criteria, formalized study selection, and quantitative meta-analytic pooling. The abstract reports no empirical sample sizes, effect sizes, or confidence intervals.
Cited by
- contradicts Ophthalmological refractive traits and poor eyesight are overwhelmingly genetic.