98th Annual Meeting DOG 2000

K 556

Vertical vergence and eye torsion in patients with congenital IVth nerve palsies

H. Steffen1,2, A. V. Mudgil3, D. L. Guyton3, M. Walker1,3, D. S. Zee1,3

To find out the pattern of eye torsion associated with vertical vergence during fusion in patients with a congenital IVth nerve palsy.

Methods: 12 patients with a congenital IVth nerve palsy were required to fix upon a light emitting diode located straight ahead, 124 cm in front of the subject, with the head upright. Eye positions were recorded binocularly using the three-axis magnetic search coil. Fixation was compared with the non-paretic eye and with both eyes viewing, before and after surgery. All values were mirrored to the right eye as being paretic. Vertical vergence (VV) was defined as the difference in vertical alignment between one eye and both eyes viewing. The direction of torsion (CW and CCW) was referenced from the patient’s perspective (e.g., CW = right eye extorts, left eye intorts) and reported as the average value of the two eyes (cycloversion, CV).

Results: Preop, 6 of 12 patients could fuse their vertical phoria with both eyes viewing. In these patients VV ranged from 1.1-12.6° (mean 4.1°± SD of 4.2°) and was associated with a CW CV in four patients (range 0.6-3.2°), a CCW CV in one (0.8°) and no CV in one. Postop, Nine patients could fuse their residual hyperdeviation with a VV (range 0.5-8.1°, mean 2.5°±2.5°) that was associated with a CW CV in seven patients (range 0.3-2.9°), a CCW CV in one (-0.6°) and no CV in one. Three patients had a small overcorrection (left hyperdeviation) that was fused with a VV (range 0.8-3.6°). Of these the VV was associated with an CCW CV in two patients (0.5°,1.4°) and no CV in the third. There was a high correlation between the amount of CV and VV (preoperatively 0.82, post operatively 0.76 and 0.78).

Conclusions: The reported pattern of eye torsion during vertical vergence in normals (intorsion of the depressing eye and extorsion of the elevating eye) is preserved in patients with congenital IVth nerve palsies.

The Johns Hopkins Hospital, Depts. of Neurology1 and Ophthalmology3, 600 N Wolfe Street, Baltimore, MD 21287, U.S.A.
Dept. of Ophthalmology, University of Heidelberg, INF 400, D-69120 Heidelberg
supported by DFG (Ste 860/2-1), and NIH EYO1849