Analysis of seven methods of measuring the angle of deviation.

The correlations between seven methods of measuring the angle of deviation were assessed in two groups of subjects. Group 1 consisted of 343 subjects with normal binocular vision. Group 2 was made up of 18 subjects with strabismus. The correlation coefficients (r) between various testing procedures varied significantly in the two groups. Group 1 could be separated into three levels of correlation and group 2 could be separated into two levels of correlation based on the 95% confidence limits of the correlation coefficients. Significant differences also could be demonstrated in the average measured values of the angle of deviation of group 1, while the second group was indistinguishable at the 5% significance level using a one-way analysis of variance procedure. These data are briefly discussed in light of their clinical implications.