The Journal of craniofacial surgery | 2019

The Type and Content of Collagen Fibers of The Levator Aponeurosis In Simple Congenital Blepharoptosis Patients.



BACKGROUND\nThe pathogenesis of congenital blepharoptosis remains controversial and most of the studies focused on the histologic changes of the levator muscle. However, thickening of the aponeurosis was reported in congenital blepharoptosis. And the thickness of the levator aponeurosis was found to be correlated with the levator function in congenital dysmyogenic blepharoptosis.\n\n\nPURPOSE\nThe authors conducted this research to investigate the histological changes of the levator aponeurosis of simple congenital blepharoptosis patients.\n\n\nPATIENTS AND METHODS\nThe authors analyzed 12 levator aponeurosis from ptosis patients and 21 levator aponeurosis from the cadaver specimens without relative medical history. The specimens were stained with hematoxylin and eosin as well as Sirius red. The sections were examined under light-microscopy. The content and type of collagen fibers were examined with the photos taken of the sections stained with Sirius red under polarized light-microscopy.\n\n\nRESULTS\nThe content and proportion of type I collagen increased significantly in the patient group compared with the cadaver group. The proportion of type I collagen was 97.5% in the patient group, while it was 51.5% in the cadaver group. However, no correlation was found either between the levator strength, degree of ptosis and the proportion of type I collagen in the patient group or between age, gender and proportion of type I collagen in the cadaver group.\n\n\nCONCLUSIONS\nTo our knowledge, this is the first time this phenomenon was discovered. The increase of type I collagen in the levator aponeurosis of the simple congenital blepharoptosis patients may imply the increased stiffness and undermined ability of transmitting forces, dissipate energy and prevent mechanical failure in the levator aponeurosis.

Volume None
Pages None
DOI 10.1097/SCS.0000000000006135
Language English
Journal The Journal of craniofacial surgery

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