Abstract
Purpose H.J. Haase developed a set of tests for measuring associated phoria and stereopsis using a variety of different targets for each. This testing method is known as the MKH-Haase method and it is used commonly in Germany. The aim of this study was to investigate the test-retest repeatability of the distance and near associated phoria tests for the MKH-Haase charts and other clinical tests.
Methods Horizontal and vertical associated phorias were measured at distance and near for 34 symptomatic and 40 asymptomatic participants with different tests. The tests are Cross, Pointer, Double Pointer, and Rectangle tests of MKH-Haase charts at distance and near. The other common tests include the Mallett Test and the American Optical (AO) Slide at distance. At near, there are the Mallett Test, the AO Card, the Saladin Card, the Wesson Card, and the Sheedy Disparometer.
Results The 95% limits of agreement for all of the distance horizontal values for the symptomatic group were within 1.25, except for the AO Slide limits, which were larger by 0.43. The limits of agreement for the asymptomatic group were within +/- 0.875. At near, the 95% limits of agreement for most of the horizontal associated phoria tests were +/- 2.00. The exception was the symptomatic group's Sheedy Disparometer limits, which were -4.25 to 5.75. Except for the Disparometer values for the asymptomatic group, the mean between-session differences were not statistically significant different from zero based on the 95% confidence interval. The asymptomatic group's mean Disparometer value was less eso at the second session. The 95% limits of agreement for all of the vertical values at distance and near for both groups were very narrow (i.e., within +/- 0.375).
Conclusions Most of the tests showed good repeatability for both subject groups at distance and near, except for the Sheedy Disparometer. The reason for the lower repeatability could be the design of the Disparometer.