Causal relationships between 41 inflammatory cytokines and myopia: a Mendelian randomization study

AIM: To investigate the potential causal associations between 41 inflammatory cytokines and myopia using a two-sample Mendelian randomization (MR) approach. METHODS: Publicly available genome-wide association study (GWAS) datasets were utilized for this two-sample MR analysis. Inflammatory cytokine-related GWAS data were extracted from The University of Bristol's Research Data Repository, and myopia-related GWAS data were obtained from the FinnGen project. Single nucleotide polymorphisms (SNPs) associated with inflammatory cytokines were systematically selected as instrumental variables (IVs) based on three rigorous criteria: relevance, independence, and exclusion of pleiotropy. Five MR methods were employed for causal inference: the inverse-variance weighted (IVW) method as the primary analysis, supplemented by MR-Egger regression, weighted median estimator, simple mode, and weighted mode approaches. Sensitivity analyses were performed to evaluate the robustness of the causal estimates. RESULTS: A total of 773 myopia-associated SNPs were identified. MR analysis revealed that higher levels of macrophage inflammatory protein 1-α (MIP-1α) were associated with a 17% reduced risk of myopia [odds ratio (OR)=0.83; 95% confidence interval (CI): 0.69-0.99; P