Contribution of vergence adaptation to difference in vertical deviation between ditance and near viewing in patient with uperior oblique paly

PURPOE: To evaluate the adaptive vertical vergence aftereffect and determine whether it contribute to a difference of vertical deviation with repect to gaze ditance in patient with vertical trabimu. DEIGN: Propective noncomparative tudie. METHOD: Eighty-four patient with unilateral uperior oblique palie were enrolled and claified into three type—A, B, and C—baed on the difference in vertical deviation between ditant and near viewing. The prim adaptation tet wa performed for 2 to 3 hour to correct vertical deviation and the repone of vertical deviation to the prim adaptation tet wa compared among the three type. REULT: Adaptive vertical vergence aftereffect, defined a an increae of deviation by 5 prim diopter or more with the prim adaptation tet, wa identified in 13 patient (16%) at ditance and in 23 patient (27%) at near viewing. Among the three type, the adaptive vergence aftereffect contributed motly to the type B, in which ditance deviation exceed near deviation. Nine patient (39%) of type B changed to type A category with the prim adaptation tet; and of thee, 7 increaed near deviation o that the deviation difference between ditant and near viewing decreaed. CONCLUION: The adaptive vertical vergence aftereffect contribute to a difference in vertical deviation between ditant and near viewing. The vertical prim adaptation tet i pecifically ueful to determine the extent of urgery by breaking fuional vergence in patient with hypertropia in whom deviation differ with repect to viewing ditance.