Myopia May Protect Against Diabetic Retinopathy

This study is the first to demonstrate a casual relationship between myopia and DR by analyzing single nucleotide polymorphisms associated with different forms of ametropia. Its findings may have implications for future research on DR risk among patients with refractive error. Photo: Steven Ferrucci, OD. Click image to enlarge. Several observational studies have indicated that myopia may delay the onset and progression of diabetic retinopathy (DR), while others have found no clear association. Meta-analyses also indicate similar findings, yet these are also based on observational data. To confirm the causal link, there is a need for Mendelian randomization (MR) studies, which use genetic variation as instrumental variables to investigate causality. One such study was recently published in BMJ Open Ophthalmology, employing a two-sample MR approach to explore the causal associations between ametropia—including myopia, hypermetropia and astigmatism—and DR. The analysis revealed that myopia may actually have an inhibitory effect on the development of DR; meanwhile, neither hyperopia nor astigmatism displayed a casual relationship with DR risk.Participants were drawn from databases of genome-wide association studies, encompassing thousands of individuals diagnosed with diabetes. The researchers analyzed genetic data linked to refractive error traits, focusing on a total of 38 single nucleotide polymorphisms associated with myopia, hyperopia and astigmatism.The study indicated that in individuals with myopia, particularly high myopia, the refractive error exhibited a protective effect against the development of DR. However, the same was not true for the other two forms of ametropia—hypermetropia and astigmatism—neither of which were found to have a statistically significant effect on DR. In their paper, the study authors relay the significance of this research. “In contrast to the observational studies prevalent in the existing literature, the use of the MR method in this study enhanced the reliability of the research findings, thereby broadening the scope of traditional observational research,” they wrote. As the first study to identify a casual relationship between myopia and DR, the researchers noted that these findings offer “valuable insights into our understanding of the underlying mechanisms and pathophysiology of the condition, thereby providing useful references for future research.” They concluded, “Further investigations are warranted to elucidate myopia’s protective mechanisms.”Click here for the journal source. Ma Q, Yao H, Wang S, et al. Causal association between different types of ametropia and risk of diabetic retinopathy: a two-sample Mendelian randomization study. BMJ Open Ophthalmol. 2025;10:e001909. This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.