Axial length: an underestimated endophenotype of myopia.

Myopia is a major threat for vision health across the world. Around 1 in 4 in the West and over 3 in 4 in the East are suffering from this common eye disorder. It is a complex trait affected by both genetic and environmental determinants. Axial length is an essential man-made parameter generated from ocular biometric components. It represents a combination of anterior chamber depth, lens thickness and vitreous chamber depth. Meanwhile, it is an endophenotype of the phenotype of myopia. In the mainstream genetic studies on vision science, it is always treated only as a parameter rather than an endophenotype. However, in this article, the potential advantages are discussed for axial length analysed as an endophenotype independently. It may provide solutions for the exploration of myopia genetics.