J Korean Ophthalmol Soc.
1991 Dec;32(12):1031-1040.
Histologic Findings of the Levator Muscle in Congenital and Acquired Ptosis
- Affiliations
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- 1Department of Ophthalmology, College of Medicine, Yeung Nam university, Daegu, Korea.
Abstract
- The authors have studied 132 biopsy specimens of the levator muscle by light microscopy and electron microscopy, after the external levator resetion for congen ital and acquired ptosis in 98 patients. Severe atrophy and complete absence of the levator muscle fiber were observed frequently in the all types of congenital and acquired ptosis, Fibrosis and fatty infiltration of the levator muscle and Miiller's muscle were examined in the specimens with severe atrophy of muscle fibers, There was no histopathological difference between congenital and acquired ptosis. On histochemical detection of muscle fibers using ATPase stain, lightly stained type I fibers of the levator muscle were larger in amount than darkly stained type II fibers and atrophy of the two fiber was similar in degree. Muller's muscle fiber was preserved well in normal structure.
