CH, but not CRF, was significantly lower in high myopia patients compared to that in normal subjects. The results indicate that some compromised aspects of the biomechanical properties of cornea may exist in people with high myopia.

Background Myopia is a good model for understanding the interaction between genetics and environmental stimuli. Here we dissect the biological processes affecting myopia progression. Methods Human Genetic Analyses: (1) gene set analysis (GSA) of new genome wide association study (GWAS) data for 593 individuals with high myopia (refraction ≤ -6 diopters [D]); (2) over-representation analysis (ORA) of 196 genes with de novo mutations, identified by whole genome sequencing of 45 high-myopia trio families, and (3) ORA of 284 previously reported myopia risk genes. Contributions of the enriched signaling pathways in mediating the genetic and environmental interactions during myopia development were investigated in vivo and in vitro . Results All three genetic analyses showed significant enrichment of four KEGG signaling pathways, including amphetamine addiction, extracellular matrix (ECM) receptor interaction, neuroactive ligand-receptor interaction, and regulation of actin cytoskeleton pathways. In individuals with extremely high myopia (refraction ≤ -10 D), the GSA of GWAS data revealed significant enrichment of the HIF-1α signaling pathway. Using human scleral fibroblasts, silencing the key nodal genes within protein-protein interaction networks for the enriched pathways antagonized the hypoxia-induced increase in myofibroblast transdifferentiation. In mice, scleral HIF-1α downregulation led to hyperopia, whereas upregulation resulted in myopia. In human subjects, near work, a risk factor for myopia, significantly decreased choroidal blood perfusion, which might cause scleral hypoxia. Interpretation Our study implicated the HIF-1α signaling pathway in promoting human myopia through mediating interactions between genetic and environmental factors. Funding National Natural Science Foundation of China grants; Natural Science Foundation of Zhejiang Province.

Myopia is a refractive error of the eye that is prevalent worldwide. The most extreme form, high myopia, is usually associated with other ocular disorders such as retinal detachment, macular degeneration, cataract, and glaucoma, and is one of leading causes of blindness. The etiology is complex and has not been fully elucidated. In this study, we identified a novel missense variant of the CCDC111 gene (NM_152683.2: c.265T > G; p.Y89D) in a high myopia family by exome sequencing. The variant was identified in 4 patients from an additional 270 sporadic high myopia patients, but not found in 270 controls. The amino acid is highly conserved across species, and variants giving rise to amino acid substitutions are predicted to be functionally damaging. The CCDC111 gene was ubiquitously expressed in primary cell cultures from human eye tissue, including corneal epithelial cells, choroidal melanoma cells, scleral fibroblasts, retinal epithelial cells, retinal Müller cells, and lens capsule epithelial cells. In summary, our results suggested that the CCDC111 may be a susceptibility gene for high myopia.