The Effect of Vertical Displacement of Horizontal Muscles on the Deviation in Primary Position

Abstract

A retrospective review was done to determine if the amount of horizontal surgery should be modified when combined with vertical displacement for A or V patterns. Eight patients with V pattern exotropia and 16 patients with A pattern esotropia who underwent either bilateral lateral rectus or bilateral medial rectus surgery with offsets of one-half tendon width were compared to compatible control groups who had horizontal surgery alone. No statistically significant difference in the amount of correction achieved was found. It was thus concluded that the amount of horizontal surgery performed should not be altered to compensate for vertically offsetting these muscles.

• strabismus
• vertical offsets
• A pattern
• V pattern