REGULATION OF STATIC AND DYNAMIC OCULAR ALIGNMENT IN PATIENTS WITH TROCHLEAR NERVE PARESES

Ocular alignment and saccades were studied in seven patients with troc hlear nerve pareses, before and after strabismus surgery, Prior to sur gery, a position-dependent vertical ocular misalignment was present, a nd downward saccades were hypometric in the paretic eye, Strabismus su rgery reduced the magnitude and position-dependence of the static misa lignment. Saccade conjugacy improved in the patients with congenital p areses, and in the patient with a gradual-onset acquired paresis, but less improvement occurred in subjects with traumatic pareses. The post -operative change in saccade conjugacy relative to the change in stati c alignment correlated with pre-operative vertical vergence, suggestin g that changes in saccade yoking depend on an interaction between sacc ades and vertical vergence.