Oxidative stress in the levator aponeurosis in Asian involutional blepharoptosis

Purpose: To analyze the histopathology and expression of 8-hydroxydeoxyguanosine (OHdG), a marker of oxidative stress, in the levator aponeurosis tissues of involutional aponeurotic and congenital blepharoptosis patients, and adult subjects with no history of blepharoptosis. Methods: Fourteen and 4 levator aponeurosis tissues obtained from Asian patients with involutional and congenital blepharoptosis and 3 normal adult tissues were examined. All tissues were fixed in 4% paraformaldehyde, embedded in paraffin, and then submitted for hematoxylin and eosin staining and immunohistochemistry with anti-8-OHdG antibody. Results: The levator aponeurosis tissues contained spindle smooth muscle fibers and striated muscles. Nuclear immunoreactivity for 8-OHdG was noted in striated and smooth muscle cells in all the tissues. The 8-OHdG-positive rate was significantly lower in congenital blepharoptosis than involutional blepharoptosis (p < 0.05). Moreover, the number of 8-OHdG-positive striated muscle cells was significantly higher in the involutional blepharoptosis than normal tissues (p < 0.05). In contrast, there was a rare positive 8- OHdGimmunoreactivity of smooth muscle cells in the aponeurotic tissues of the involutional blepharoptosis patients. Conclusions: Levator aponeurosis in involutional aponeurotic blepharoptosis tissues showed oxidative stress in the muscle, indicating that oxidative stress plays a potential role in the pathologic study of the disease.