Rotational malpoition during laer in itu keratomileui

PURPOE: To invetigate the degree of rotational malpoition in eye undergoing laer in itu keratomileui. DEIGN: Propective obervational tudy. METHOD: We meaured the rotational poition of 240 eye of 169 patient who underwent treatment for myopic or hyperopic atigmatim with the Alcon ummit Autonomou (Orlando, Florida) LADARViion excimer laer. Immediately preoperatively, each eye wa marked while the patient wa eated upright. Rotational poition wa meaured on the upine patient immediately before beginning the laer expoure. REULT: For all 240 eye, mean ± tandard deviation (D) torional mialignment wa 4.1 ± 3.7 degree (right eye 3.8 ± 3.7 degree, left eye 4.2 ± 3.6 degree). A total of 20 eye (8%) had a deviation of greater than 10 degree. CONCLUION: A 4 degree and 10 degree mialignment would theoretically reult in a 14% and 35% undercorrection of atigmatim, repectively. Preoperative marking of the upright patient and ubequent rotational alignment of the upine patient before laer treatment may reduce the error in correction of atigmatim during excimer laer viion correction urgery.