A Study of Histopathologic Evaluation and Clinical Correlation for Isolated Congenital Myogenic Ptosis and Aponeurotic Ptosis

Abstract

Purpose: To evaluate light microscopy and transmission electron microscopy findings of levator muscle/aponeurosis materials and their correlation with clinical findings in isolated congenital myogenic and aponeurotic blepharoptosis. Methods: Demographic and clinical data were obtained from patients. Qualitative and quantitative evaluations for muscle fiber morphology were performed using light microscopy and transmission electron microscopy on tissue samples which were obtained from the most proximal part of the aponeurosis excised during levator muscle/aponeurosis resection surgery. Results: Seventeen (55%) of the cases were isolated congenital myogenic ptosis, and 14 (45%) were aponeurotic ptosis. Muscle bundle splitting, cytoplasmic loss, and centrally located nuclei were observed in both groups. Muscle tissue covered 25% of the sample in 67% of the cases, 50% in 11%, 75% in 11%, and 100% in 11% in the myogenic group. In the aponeurotic group, muscle tissue covered 25% of the sample in 44.5% of the cases, 50% in 11%, and 100% in 44.5% (χ 2, p = 0.52). Myofibrillar loss areas accompanied by Z-line disorganization which were occupied by degenerated organelles were present in both groups under transmission electron microscopy, and findings were not significantly different between groups (χ 2, p > 0.05). Mean mitochondrial diameter was significantly larger in aponeurotic ptosis (Mann-Whitney U, p = 0.047). No correlation was found between functional and microscopic parameters. Conclusion: Decreased amount of striated muscle and the presence of fiber damage indicators were observed in both groups. Muscle fiber loss in myogenic ptosis may be a feature of muscle dysgenesis. Ultrastructural damage in aponeurotic ptosis may be explained with increased oxidative stress or long-term contractile stress. Further genetic and immunohistochemical studies will be helpful to further understand the pathogenesis of diseases.

The Recurrence of Ptosis after Correction Surgery Is Associated with Refractive Error

“…Similar results were reported in a previous study [ 18 ]. Previous research reported a decreased amount of striated muscle and fiber damage indicators in aponeuroses obtained from patients with simple congenital ptosis [ 34 ]. Heisel et al [ 31 ] reported histological disorganization and fibrosis in the orbital septum of patients with congenital ptosis and poor levator function.…”

Application of Surgery Combined With Platelet-Rich Plasma in the Correction of Mild to Moderate Blepharoptosis

“…Clinically, most patients with blepharoptosis have abnormal structure or function of levator aponeurosis. 2 Pathologically, the main manifestations are varying degrees of injury or degeneration of levator aponeurosis such as thinning, elongation, rupture, breaking, and curling. Light microscope shows collagen degeneration, fat infiltration or fibrosis in the lesion of aponeurosis.…”

“…Light microscope shows collagen degeneration, fat infiltration or fibrosis in the lesion of aponeurosis. 2 At present, there are many kinds of correction, mainly by shortening or folding the levator aponeurosis to strengthen the strength of the levator muscle. 3 However, the operation itself does not fundamentally repair the histologic structure of the levator aponeurosis or improve its function, and only mechanically shortens or folds the aponeurosis, which may be one of the causes of postoperative recurrence and other complications.…”

Reduced mitochondrial fission and impaired energy metabolism in human primary skeletal muscle cells of Megaconial Congenital Muscular Dystrophy

“…The ultra-thin sections were stained with uranyl acetate and lead citrate, analyzed with a TEM and attached digital camera (TEM, JEM1400, Japan, GATAN, Germany). The length and width of mitochondria (at least 50 mitochondria per section) were measured with DigitalMicrograph (Gatan Inc., USA) software 6 , 59 , 60 .…”