Light, near work, and ocular remodeling and during emmetropization and myopia development in children

University Of Houston, Houston TX

Investigators

Linked publications & trials

Abstract

PROJECT SUMMARY/ABSTRACT Myopia, or nearsightedness, is an epidemic, with up to 90% of the population in some urbanized countries affected. Efforts have increased to understand the regulatory mechanisms underlying myopic eye growth due to the potentially blinding complications and socioeconomic burden associated with myopia. The long term goal of this work is to provide the scientific basis for effective environmental and behavioral treatment options to slow myopia onset and progression in children and to better understand structural changes in the myopic eye that render it more susceptible to ocular pathologies. Our central hypothesis is that reduced high intensity light exposure and increased time engaged in near work contribute to myopia onset and progression. We also hypothesize that the choroid, inner retinal vasculature, retinal morphology, and optic nerve head undergo significant remodeling during myopia development, which contribute to associated pathologies later in life. Refractive development is regulated by a complex interaction between genetic, environmental, and behavioral factors. Evidence suggests that outdoor time is protective against myopia onset, with some studies also showing that outdoor time decreases myopia progression. Numerous studies strongly support a role of near work in myopia onset and progression. However, there are conflicting findings, with some studies reporting no association. Inconsistent results are due to the variable and subjective nature by which light exposure and near work have traditionally been assessed. Based on gaps in the existing literature and our preliminary work, we will carry out the following studies to quantify the effects of environment and behavior on eye growth and the effects of eye growth on ocular structure in children; each aim will follow children for a two-year period. 1) Longitudinal objective and continuous measurement of personal light exposure over five one-week periods to determine its influence on refraction and axial length change; 2) Longitudinal objective measurement of near work over five one-week periods, paired with a visual activity questionnaire, to determine the influence of near viewing behaviors and electronic device use on refraction and axial length change; 3) Optical coherence tomography (OCT) imaging, OCT angiography (OCTA), and adaptive optics scanning laser ophthalmoscopy (AOSLO) imaging at one year intervals to investigate changes in foveal cone photoreceptor density, foveal pit morphology, foveal avascular zone characteristics, choroidal thickness, inner retinal vascular perfusion, and optic nerve head parameters in association with refraction and axial length change. The proposed studies are intended to fill a critical void in our understanding of the precise influence of environmental and behavioral factors on eye growth and myopia and how the eye remodels in myopia. This work will contribute to the development of evidence- based therapies, thereby reducing ocular complications and socioeconomic burden related to myopia.