Congenital upper lid retraction: A histological and ultrastructural study

Abstract

Congenital upper lid retraction is a rare anomaly in which one or both eyelids are abnormally elevated. Unilateral involvement in males is the most frequent presentation. An intrinsic disorder of the levator or Muller muscle is the most likely etiology, since neurological, systemic, or orbital abnormalities have not been described. The authors describe two cases of congenital upper lid retraction. The levator muscle from one patient and an age matched control were examined histologically and ultrastructurally. The lid retraction and control specimens demonstrated similar fiber diameters, similar amount of connective tissue between fascicles, and absence of inflammatory cells or intercellular edema. Electron microscopy of the lid retraction specimen showed small areas of Z-line streaming and myofibrillar disarray which were not demonstrated in the control specimen. The significance of these ultrastructural findings is unclear, since they have been reported in some healthy young subjects, as well as in several muscle disorders.

Key Words:

• eyelid retraction
• congenital
• levator muscle