Randot Preschool Stereoacuity test: Normative data and validity

Abstract

Introduction: The Randot Preschool Stereoacuity test (RPST) is a widely used three-book test for the assessment of binocular status. Using a prototype, we reported high testability in children as young as 3 years, validity data, and some normative data. An artifact noted for 1 of the 800 seconds stimuli in the prototype led to a redesign. Here we report normative and validity data for the final three-book version of the RPST. In addition, we report normative data for a new fourth book that adds finer disparities. Methods: The RPST was administered to 4338 normal children ages 3 to 18 years and 39 adults in both clinical and screening settings. In addition, the RPST along with the new fourth book that added 30 and 20 seconds disparity levels was administered to 1402 normal children ages 3 to 18 years and 33 normal adults. Both the four-book RPST and the Randot circles were administered to 242 patients aged 3 to 18 years. Results: Mean normal stereoacuity improved from 100 seconds at 3 years of age to 60 seconds by 5 years and 40 seconds by 7 years. The lower limit of normal was 400 seconds at 3 years, 200 seconds at 4 years, and 60 seconds at 7 years. Using the new four-book version, further improvement in mean stereoacuity could be appreciated beyond 7 years of age to 30 seconds in the 11- to 18-year-old and adult groups. Among the 242 patients, RPST stereoacuity (four-book test) was strongly associated with Randot circle stereoacuity (c2 = 261.0, p < 0.001). Conclusions: Normative data for the RPST show a monotonic improvement of stereoacuity from age 3 years through teens. Patient data support the validity of the four-book version of the test.