A Comparison of Different Stereoacuity Tests

Objective: To compare the first generation stereoscopic test charts, the third generation stereoscopic test charts, random-dot stereograms and the distance randot stereotest in patients with intermittent exotropia. Methods: In this prospective study, 51 patients with intermittent exotropia were examined by the first generation stereoscopic test charts, the third generation stereoscopic test charts, random-dot stereograms and the Distance Randot stereotest preoperatively and 2 and 10 weeks postoperatively. A wilcoxon signed-rank test and chi-square test were used. Results: The differences between the third generation and first generation stereoscopic test charts had no statistical significance (U=1.338, P=0.181), but the results of the third generation stereoscopic test charts were superior to that of the first generation stereoscopic test charts. Preoperatively and 2 and 10 weeks postoperatively, the results between the first generation and the third generation stereoscopic test charts showed improvement and the differences were statistically significant (χ2=65.5, 58.5, both P<0.001). The differences between the Distance Randot stereotest and random-dot stereograms had no statistical significance (U=1.332, P=0.183), but the results of the Distance Randot test were superior to that of random-dot stereograms. Preoperatively and 2 and 10 weeks postoperatively, the results of the random-dot stereograms and the Distance Randot stereotest showed improvement and the differences were statistically significant (χ2=76.0, 77.0, both P<0.001). Conclusions: Surgical intervention is of significance for improving the near and distance stereopsis of patients with intermittent exotropia. The third generation stereoscopic test charts can replace the first generation stereoscopic test charts in the examination of near stereopsis, and the Distance Randot test can replace the random-dot stereograms in the examination of distance stereopsis. Key words: intermittent exotropia; stereopsis; stereoscopic test charts; the distance randot stereotest