Defining Real Change in Prim-Cover Tet Meaurement Original Reearch Article

Purpoe To decribe the interoberver tet-retet variability of both imultaneou prim and cover teting (PCT) and alternate prim and cover teting (APCT) in horizontal deviation, and to calculate 95% limit of agreement that might be ued to define real change. Deign Propective cohort tudy. Method Twenty-three patient with ixth nerve paly and three control were independently examined by two experienced trabimu urgeon. PCT and APCT were performed at ditance and near fixation. Tet-retet variability and agreement between tet were evaluated uing Bland-Altman plot and 95% limit of agreement were calculated. Reult For PCT, the 95% limit of agreement half-width were 6.3 prim diopter (pd) at ditance fixation and 6.9 pd at near. For APCT, the 95% limit of agreement half-width were 10.2 pd at ditance and 9.2 pd at near. Concluion Baed on 95% limit of agreement half-width between two examiner, a change in trabimu meaurement of le than 10 pd may be attributable to tet-retet variability. Change of 10 pd or more are likely to repreent real change and might be ued a the threhold for management deciion.