Choroidal thickness measurements: challenges in clinical practice

The increased worldwide prevalence of myopia has intensified the interest of researchers in determining causes, mechanisms, and predisposing factors that lead to its onset and progression over time. The eye growth, that is strictly linked to the refractive status and the development of myopia, is controlled by complex interactions between genetic and environmental factors. Neural mechanisms in the retina can detect the presence of defocus and generate signals that alter axial growth in a manner that eliminates optical errors. The choroidal seems to be in charge of this initial compensatory response to retinal defocus. In particular, a prolongated visual work at a near distance can induce a hyperopic defocus and the subsequent transient choroidal thinning, which, over time, would produce an irreversible ocular elongation of the scleral fibrous structures, structuring the condition of myopia. Our study is focused on finding a reliable and repeatable method to measure choroidal thickness from OCT images, and its transient response in relation to various stimuli, which could increase understanding of the relationship between the two phenomena in causing future myopization.