Assessment of precision and reliability of a novel computerized heterophoria test.

PURPOSE

To assess the precision and reliability of a novel computerized heterophoria test (CHT).

METHODS

One hundred and three subjects aged 20 to 48 (27.37 ± 5.15) were recruited from Wenzhou Medical University. All subjects with corrected spectacles were examined with CHT and a prism-neutralized objective cover test (POCT) in a randomized order. They were then re-examined with CHT within 1 week. Their heterophoria was measured at three different distances (3 m, 0.77 m and 0.4 m); the average was recorded after three consecutive measurements. Inter-examiner repeatability, intra-examiner repeatability of CHT and agreement between CHT and POCT were evaluated.

RESULTS

There was no significant difference among repeated measurements using CHT (all  > 0.05). The difference between POCT and CHT was statistically significant at three distances (all  < 0.001). However, the mean absolute difference was 1.20, 1.93, and 2.41, all of which were significantly smaller than the permissible range of error (4) at three different distances (all  < 0.001).

CONCLUSION

The CHT demonstrated excellent inter- and intra-examiner repeatability, as well as good correlation with POCT. The differences between CHT and POCT were within the permissible range of error, indicating that CHT could provide a precise and reliable measurement for clinical applications.