Incidence and Progression of Myopia in Early Adulthood

Abstract

Importance: Myopia incidence and progression has been described extensively in children. However, few data exist regarding myopia incidence and progression in early adulthood. Objective: To describe the 8-year incidence of myopia and change in ocular biometry in young adults and their association with the known risk factors for childhood myopia. Design, Setting, and Participants: The Raine Study is a prospective single-center cohort study. Baseline and follow-up eye assessments were conducted from January 2010 to August 2012 and from March 2018 to March 2020. The data were analyzed from June to July 2021. A total of 1328 participants attended the baseline assessment, and 813 participants attended the follow-up assessment. Refractive information from both visits was available for 701 participants. Participants with keratoconus, previous corneal surgery, or recent orthokeratology wear were excluded. Exposures: Participants' eyes were examined at ages 20 years (baseline) and 28 years. Main Outcomes and Measures: Incidence of myopia and high myopia; change in spherical equivalent (SE) and axial length (AL). Results: A total of 516 (261 male [50.6%]) and 698 (349 male [50.0%]) participants without myopia or high myopia at baseline, respectively, were included in the incidences analyses, while 691 participants (339 male [49%]) were included in the progression analysis. The 8-year myopia and high myopia incidence were 14.0% (95% CI, 11.5%-17.4%) and 0.7% (95% CI, 0.3%-1.2%), respectively. A myopic shift (of 0.50 diopters [D] or greater in at least 1 eye) occurred in 261 participants (37.8%). Statistical significance was found in longitudinal changes in SE (-0.04 D per year; P