Adult-onset myopia: The genes in myopia (GEM) twin study

Abstract

PURPOSE. To report the frequency of adult-onset myopia in a large cohort of Caucasian twins that were assessed as part of the Genes in Myopia (GEM) twin study and to quantify the genetic contribution in adult-onset myopia using the classic twin model. METHODS. All twins aged 18 years or older were invited to participate in the GEM twin study through the Australian Twin Registry (ATR). Each twin completed a standard questionnaire and underwent a comprehensive eye assessment, including cycloplegic objective examination. Adult-onset myopia was defined as having the first spectacle/contact lens correction at the age of 18 years or older. Myopia was defined as spherical equivalent worse than or e..