Randomized Trial of Bifocal Spectacles vs Single Vision Spectacles for Esotropia Greater at Near

Abstract The study is being conducted to compare whether an optical correction of bifocal spectacle lenses (BFL) or single-vision spectacle lenses (SVL) is more effective for the treatment of children with esotropia greater at near. Children will be randomized to be treated with BFLs or SVLs for 3 years and be evaluated at regular intervals throughout the study to determine whether their condition has worsened. Children whose condition worsens during the study will either start BFL treatment (if randomized to SVL group) or continue BFL treatment (if randomized to BFL group) for 2 months to allow assessment of outcome in BFLs, and then be released to treatment at investigator discretion while continuing in study follow-up. Children whose condition has not worsened during the study will start or continue BFL (depending on treatment group) for 2 months at 3 years. All children return at 38 months to assess binocular function. The effectiveness and safety of both treatments will be compared.