Ptosis with contralateral lid retraction due to excessive innervation of the levator palpebrae superiorus

Two patients are presented with unilateral ptosis and contralateral lid retraction. The lid retraction disappears upon manual elevation of the ptotic lid. Each patient with this phenomenon would be expected to have a frank tropia, or monofixation syndrome and prefer to fix with the ptotic eye. Extraordinary innervation is transmitted to the levator of the ptotic eye and, since we believe the levators follow Hering's law, this excessive innervation is also transmitted to the contralateral levator. This results in lid retraction in the second eye. If the ptotic lid is manually elevated, levator innervation decreases and the contralateral lid retraction disappears. This previously unreported maneuver of manually elevating the ptotic lid is superior to patching the ptotic eye for a period of days, the previous method for demonstrating this phenomenon. These considerations are important in the evaluation of lid retraction, and in determining the nature and extent of corrective surgery.