Abstract The choroid is a multifunctional dynamic structure located between the sclera and the Bruch membrane, which may be involved in the regulation of eye growth and the development of myopia. Choroidal thickness may serve as an important biomarker for predicting the development of myopia and the effectiveness of myopia control treatments in children and adolescents. The study reviews and summarizes the physiological structure and measuring methods of the choroid, and discusses its influencing factors including age, physiological changes, refractive status, axial length, drug effects, optical environment and so on. The review points out the potential applications of choroidal thickness in myopia research among children and adolescents.

Objective: To analyze research hot spots and trends on myopia in children and adolescents in China, and to provide a reference for the future development of this research field. Methods: Using CiteSpace software, 725 eligible Chinese documents published over a 22 year period were sourced from CNKI, VIP and Wanfang Chinese databases, were analyzed during 2000-2021. The data were visualized by a keyword co occurrence map, and clustering, as well as burst and author cooperative networks. Results: The research field of myopia in children and adolescents in China had undergone three stages:an initial formation period, development period and rapid growth period, and it was expected that the annual number of papers will maintain an increasing trend in the future. "Myopia" "adolescents" "children" and "students" were the most frequent keywords(667, 535, 288, 47). The keyword burst "adolescents" started the earliest, and "students" had the largest burst strength and duration. Zhang Ning, Tang Wenting, Tao Fangbiao, Yang Xiao and others have made important contributions to this research field. Conclusion In recent years, the research focus in this field has gradually shifted toward the influencing factors, as well as prevention and treatment measures of child and adolescent myopia. The trend of myopia in young children and adolescents is obvious. In the future, research on the prevention, control and treatment of myopia in children and adolescents will become a hot spot.

Abstract The incidence of myopia in children and adolescents has increased in recent years, with an earlier onset trend. During the same time, sleep problems are prevalent in children and adolescents, including insufficient sleep duration and delayed sleep timing. Sleep, as a cyclical life activity influenced by the circadian rhythm, plays an important role in eye growth and refractive development. This review examines the associations between sleep, circadian rhythm, and occurrence of myopia in children and adolescents across human and animal studies, and discusses the underlying biological processes, so as to offer scientific justification for the prevention of myopia in children and adolescents.