The Ocular Cyclotorsion Induced by the Positional Change

Cho, H H; Sohn, M A

Abstract

To investigate positionally induced ocular cyclotorsion and its related change of astigmatic axis, fundus cyclotorsion was observed with color fundus camera. Fundus photographs were taken in 40 ophthalmologically normal subjects [80 eyes]. We examined the horizontal distance from temporal edge of disc to foveola and vertical distance from horizontal line extended temporally from the geometric center of optic nerve head to foveola in both the seated and supine positions. The mean difference in the vertical foveoal distance between the seated and supine position were 0.024 +/-0.258DD [P=0.55] in right eye and -0.061 +/-0.251DD [P=0.126] in left eye. There was no statistically significant difference in foveal distance below the horizontal meridian extended temporally from geometric center of optic nerve head between the seated and supine position. These data show that the eyes do not undergo positionally induced ocular cyclotorsion when a patient moves from a seated to a supine position and this suggests that cylinder axis does not change significantly when most subjects move from the seated to supine position.