Mendelian randomization analysis reveals a causal relationship between preterm birth and myopia risk

Area of Science:

• Ophthalmology
• Genetics
• Epidemiology

Background:

• Preterm birth is linked to higher myopia risk, but causality is debated due to confounding factors and reverse causality.
• Mendelian randomization (MR) offers a robust method to investigate causal relationships using genetic variants.
• This study employed a two-sample MR strategy to assess the causal link between preterm birth and myopia.

Purpose of the Study:

• To investigate the potential causal relationship between preterm birth and the risk of developing myopia.
• To utilize genetic variants as instrumental variables for a robust causal inference.
• To overcome limitations of traditional epidemiological studies in establishing causality.

Main Methods:

• A two-sample Mendelian randomization (MR) study design was implemented.
• Genetic variants (SNPs) from genome-wide association studies (GWAS) served as instrumental variables.
• Multiple regression models (MR-Egger, weighted median, inverse variance weighted, Weighted mode) and sensitivity analyses (leave-one-out, funnel plot, MR-Egger test) were used.

Main Results:

• MR analysis indicated a significant causal effect of preterm birth on myopia risk (p < 0.05).
• A one standard deviation increase in preterm birth was associated with approximately a 30% increase in myopia risk.
• Sensitivity analyses confirmed the robustness and stability of the findings.

Conclusions:

• Evidence supports a causal relationship between preterm birth and increased myopia risk.
• The observed association is unlikely due to confounding factors or reverse causality.
• Specific SNP loci (rs6699397, rs10871582, rs2570497) may be involved in pathogenic mechanisms, potentially via intraocular cytokine regulation.