The Effect of Acute Superior Oblique Palsy on Torsional Optokinetic Nystagmus in Monkeys
Open Access
- 1 April 2008
- journal article
- Published by Association for Research in Vision and Ophthalmology (ARVO)
- Vol. 49 (4), 1421-1428
- https://doi.org/10.1167/iovs.07-0989
Abstract
Purpose. To investigate the effects of acquired superior oblique palsy (SOP) and corrective strabismus surgery on torsional optokinetic nystagmus (tOKN) in monkeys. methods. The trochlear nerve was severed intracranially in two rhesus monkeys (M1 and M2). For each monkey, more than 4 months after the SOP, the ipsilateral inferior oblique muscle was denervated and extirpated. For M2, 4 months later, the contralateral inferior rectus muscle was recessed by 2 mm. tOKN was elicited during monocular viewing of a rotating stimulus that was rear projected onto a screen 43.5 cm in front of the animal. Angular rotation of the stimulus about the center was 40 deg/s clockwise or counterclockwise. results. The main findings after trochlear nerve sectioning were (1) the amplitude and peak velocity of torsional quick and slow phases of the paretic eye was less than that in the normal eye for both intorsion and extorsion, and (2) the vertical motion of the paretic eye increased during both torsional slow and quick phases. After corrective inferior oblique surgery, both of these effects were even greater. conclusions. Acquired SOP and corrective inferior oblique-weakening surgery create characteristic patterns of change in tOKN that reflect alterations in the dynamic properties of the extraocular muscles involved in eye torsion. tOKN also provides information complementary to that provided by the traditional Bielschowsky head-tilt test and potentially can help distinguish among different causes of vertical ocular misalignment.Keywords
This publication has 7 references indexed in Scilit:
- Acute Superior Oblique Palsy in Monkeys: I. Changes in Static Eye AlignmentPublished by Association for Research in Vision and Ophthalmology (ARVO) ,2007
- Acute Superior Oblique Palsy in Monkeys: III. Relationship to Listing’s LawPublished by Association for Research in Vision and Ophthalmology (ARVO) ,2007
- Acute Superior Oblique Palsy in Monkeys: II. Changes in Dynamic Properties during Vertical SaccadesPublished by Association for Research in Vision and Ophthalmology (ARVO) ,2007
- Ocular rotation axes during dynamic Bielschowsky head-tilt testing in unilateral trochlear nerve palsy.Published by Association for Research in Vision and Ophthalmology (ARVO) ,2004
- Binocular coordination of saccades in children with strabismus before and after surgery.2002
- Saccadic velocity measurements in strabismus.1983
- Extraocular Muscles and Head TiltingAmerican Journal of Ophthalmology, 1967