Evaluation of clinical stereoacuity tests

Sixty children ages two to seven were separated into two age-matched groups of thirty each, one consisting of a group of normal children, and the other a strabismic-anisometropic group. All subjects were examined with four currently available stereoacuity tests, the RDE, Randot, Titmus, and the TNO. Significant differences in performance were found between the two groups. Across all tests there was a 10 to 17% over-referral rate and a 33-37% under-referral rate. Untestability in the normal group ranged from 3.3-6.7% across tests, while in the patient group it ranged from 3.3-20.0%. The under-referral rate is unacceptable and casts doubt on the value of our present stereoacuity tests in screening for subtle defects in binocular function in the young child.