Mendelian Randomization in Eye Research: Powerful, but Prone to Misuse

Mendelian Randomization in Eye Research: Powerful, but Prone to MisuseMendelian randomization (MR) was first introduced in 2003 as a natural experiment to help make causal inference in observational studies. 1 It has become a widely used method to reduce confounding in epidemiological studies. [2][3]3][4] In recent years, the number of MR studies increases exponentially, driven largely by the growing availability of large-scale genetic data.The number of PubMed-indexed MR publications across medicine has risen from 899 in 2020 to more than 6000 annually in 2024 to 2025.Ophthalmology and vision science reflect a similar trend: MR publications increased from only 17 in 2020 to over 220 in 2025, with a parallel surge in submissions to Translational Vision Science & Technology (TVST).Specifically, MR submission to TVST increased from 7 (0.8%) in 2023 to 44 (4.3%) in 2024.Whereas this growth demonstrates the community's enthusiasm for MR analysis, it also raises concerns about its appropriate use, as evidenced in several recent journal editorials.