Randot® Preschool Stereoacuity Test: Normative data and validity

IntroductionThe Randot® Preschool Stereoacuity Test is a widely used three-book test for the assessment of binocular status. Using a prototype, we previously reported high testability in children as young as 3 years, validity data, and some normative data. Here we report extensive normative and validity data for the final version of the test. In addition, we report normative data for a new, fourth book that adds finer disparities.MethodsThe Randot® Preschool Stereoacuity Test was administered to 4355 normal children aged 3 to 18 years and 39 adults in multiple settings. In addition, the Randot® Preschool Stereoacuity Test along with the new, fourth book that added 30 arcsec and 20 arcsec disparity levels was administered to 1402 normal children aged 3 to 18 years and 33 normal adults. Both the four-book Randot® Preschool Stereoacuity Test and the Randot circles were administered to 242 patients with amblyogenic conditions aged 3 to 18 years.ResultsMean normal stereoacuity improved from 100 arcsec at 3 years of age to 60 arcsec by 5 years and 40 arcsec by 7 years. The lower limit of normal was 400 arcsec at 3 years, 200 arcsec at 4 years, and 60 arcsec at 7 years. Using the new four-book version, further improvement in mean stereoacuity could be appreciated beyond 7 years of age to 30 arcsec in the 11- to 18-year-old and adult groups. Among the 242 patients, Randot® Preschool Stereoacuity Test stereoacuity was strongly associated with Randot circle stereoacuity (χ2 = 261.0, p < 0.001).ConclusionsNormative data for the Randot® Preschool Stereoacuity Test show a monotonic improvement of stereoacuity from age 3 years through the teen years. Patient data support the validity of the Randot® Preschool Stereoacuity Test.