Myopia and digit ratio in medical college students

Myopia is amongst the most common refractive errors in the world. Both environmental and genetic factors are attributed to its causation, however all factors contributing to the development of myopia is yet to be found. Recent studies show presence of sex hormone receptor in the eyes. This has been shown to have a role in the development of various ocular pathologies. The second to fourth finger length ratio (2D:4D) has been hypothesised to be determined by exposure to sex steroids prenatally and thus considered a crude measure for prenatal androgen exposure. Hence this study was initiated to assess the association between myopia and 2D:4D ratio (a proxy marker to prenatal sex steroid exposure) among 100 medical college students of either sex and explore the possibility of role of prenatal sex steroids in causation of myopia. This study showed significant negative associations between myopia and digit ratio favouring a probable causal role of sex steroids on eye growth and development of myopia.