Prim adaptation repone i ueful for predicting urgical outcome in elected type of intermittent exotropia

PURPOE: To evaluate the prevalence of prim adaptation repone in Japanee patient with intermittent exotropia (X [T]) uing the prim adaptation tet and to ae whether patient with elected type of X [T] benefit from urgical outcome to which prim adaptation repone may contribute. METHOD: In a propective tudy, 128 conecutive patient with X [T] between 1990 and 1995 were enrolled. The prim adaptation tet wa conducted by neutralizing the angle of deviation for 2 to 3 hour. Patient who howed an increae in exodeviation by 10 or more with the prim adaptation tet were defined a having a prim adaptation repone. For claification of the pattern of X [T], we choe a value of 15 a the difference between the ditance and near meaurement. REULT: The percentage of patient in whom the prim adaptation repone wa oberved at near fixation wa ignificantly larger than thoe at ditance fixation [35 (27%) patient veru 10 (8%) patient, P < .05]. Of 35 patient hown to have a prim adaptation repone at near fixation, 21 patient (83%) had the baic type of exotropia. Fourteen patient (17%) with the baic type were changed to convergence inufficiency type becaue of an increae in near deviation and were defined a peudo baic type. Patient with peudo baic type had a ignificantly better urgical outcome compared with that of true baic type, wherea in the convergence inufficiency type, no definite tendency wa found between the two ubtype, true and peudo type. CONCLUION: Patient with the peudo baic type of X [T] in whom a prim adaptation repone wa demontrated had a more favorable urgical outcome.