The RPE in Myopia Development

Abstract

Myopia is one of the most common types of refractive errors and a major cause of visual impairment worldwide. Most myopia is the product of excessive elongation of the vitreous chamber, which largely accounts for increases in eye length and uncorrected blurred distance vision. Myopia also carries an increased risk of blinding pathologies, including retinal detachment and myopic maculopathy, with no evidence of a safe level of myopia. Changes in the retinal pigment epithelium (RPE) have also been observed in myopic patients with excessively large eyes. The role of RPE in eye growth regulation and refractive development has been the subject of more recent investigations, in both animal models and in vitro cell cultures. Due to the key location and complex functions of RPE, it likely serves as a relay or conduit for retina-derived growth modulatory signals directed at the choroid and sclera, which ultimately determine vitreous chamber depth and thus overall eye length. This chapter summarizes results of recent RPE studies, including RPE-derived growth factors, neurotransmitters and their receptors, ion channels, and RPE morphological changes in the context of eye growth regulation and myopia development. Understanding the role of RPE in eye growth regulation holds promise of significant new insights into the mechanisms underlying the development of refractive errors, opening the possibility of novel therapeutic approaches to myopia control.