TY - JOUR
T1 - Acute superior oblique palsy in monkeys
T2 - III. Relationship to listing's law
AU - Tian, Jing
AU - Shan, Xiaoyan
AU - Zee, David S.
AU - Ying, Howard
AU - Tamargo, Rafael J.
AU - Quaia, Christian
AU - Optican, Lance M.
AU - Walker, Mark F.
PY - 2007/6
Y1 - 2007/6
N2 - PURPOSE. To investigate the three-dimensional orientation of the eye and its relationship to Listing's Law in monkeys with acute acquired superior oblique palsy (SOP). METHODS. The trochlear nerve was severed intracranially in two rhesus monkeys. Three-axis eye movements (horizontal, vertical, and torsion) were measured with binocular, dual search coils during fixation of targets in a 40° X 40° grid. Rotation vectors were calculated, and Listing's plane (LP) was determined by a least-squares planar fit of eye torsion as a function of horizontal and vertical position. RESULTS. The main findings were: (1) In the paretic eye, there was an immediate and sustained rotation of the orientation plane by approximately 25° in the temporal direction; (2) the thickness of LP, defined as the torsional standard deviation (SD), increased little (by 0.13° in M1 and 0.08° in M2) after SOP, and (3) the SD of intrasaccadic torsion was slightly greater than that during fixation, but there was no change after SOP. CONCLUSIONS. Acute SOP in rhesus monkeys leads to a temporal rotation of LP. This is consistent with a relatively increased extorsion in down gaze due to a loss of normal intorsion by the superior oblique muscle. The SD of torsion increased by only a small amount, implying that the validity of Listing's Law is not affected much by complete SOP, despite the large change in the orientation of LP.
AB - PURPOSE. To investigate the three-dimensional orientation of the eye and its relationship to Listing's Law in monkeys with acute acquired superior oblique palsy (SOP). METHODS. The trochlear nerve was severed intracranially in two rhesus monkeys. Three-axis eye movements (horizontal, vertical, and torsion) were measured with binocular, dual search coils during fixation of targets in a 40° X 40° grid. Rotation vectors were calculated, and Listing's plane (LP) was determined by a least-squares planar fit of eye torsion as a function of horizontal and vertical position. RESULTS. The main findings were: (1) In the paretic eye, there was an immediate and sustained rotation of the orientation plane by approximately 25° in the temporal direction; (2) the thickness of LP, defined as the torsional standard deviation (SD), increased little (by 0.13° in M1 and 0.08° in M2) after SOP, and (3) the SD of intrasaccadic torsion was slightly greater than that during fixation, but there was no change after SOP. CONCLUSIONS. Acute SOP in rhesus monkeys leads to a temporal rotation of LP. This is consistent with a relatively increased extorsion in down gaze due to a loss of normal intorsion by the superior oblique muscle. The SD of torsion increased by only a small amount, implying that the validity of Listing's Law is not affected much by complete SOP, despite the large change in the orientation of LP.
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U2 - 10.1167/iovs.06-1319
DO - 10.1167/iovs.06-1319
M3 - Article
C2 - 17525192
AN - SCOPUS:34347231991
SN - 0146-0404
VL - 48
SP - 2621
EP - 2625
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 6
ER -