Fibrous connective tissue between Müller's muscle and the palpebral conjunctiva as a reinforcement structure and a natural barrier for the upper eyelid.

This study was performed to illustrate and discuss the significance of fibrous connective tissue between the Müller's muscle and the palpebral conjunctiva. Nine upper eyelids of 6 Oriental cadavers were microscopically examined; ages at death ranged from 72 to 91 years. Tissue of the posterior lamella of the upper eyelid was removed without the orbital septum and orbital fat. Removed eyelids were incised perpendicularly at the center of the eyelid. After pretreatment, sliced sections were stained with Hematoxylin and Eosin and examined microscopically. A thick fibrous connective tissue was found to exist between the Müller's muscle and the palpebral conjunctiva. The connective tissue continued proximally to the intermuscular transverse ligament and was distally attached to the posterior site of the upper aspect of the tarsus. All cases showed infiltration of lymphocytes from the conjunctiva; however, these were completely blocked by the fibrous connective tissue and never reached Müller's muscle. This connective tissue supports eyelid traction and is a natural barrier for the Muller's muscle against conjunctivitis.