Elastin expression in the conjoint facial sheath (CFS) of patients of different ages with severe ptosis has been extensively studied, but its expression in the CFS of pediatric patients with severe ptosis with different muscle strengths remains poorly understood. The aim of the present study was to investigate the expression of elastin in the CFS and levator palpebrae superioris muscle (LM) of children with severe congenital ptosis with different LM strengths. In total, 20 pediatric patients with unilateral severe congenital ptosis (20 eyes) were included, who underwent CFS + LM complex suspension surgery from June 2020 to February 2022. Among these patients, the LM strength was 0-1 mm in 10 patients and 2-3 mm in the other 10 patients. Excess CFS and LM tissue samples were obtained from the patients during surgery, before the protein expression levels of elastin in the specimens were measured by western blotting. During the 6-month postoperative follow-up period, the good correction rate, the degree of incomplete eyelid closure and the incidence of complications were observed. Western blotting results showed that, compared with that in the 0-1 mm group, elastin expression was not significantly different in the CFS, whereas it was significantly increased (P=0.021) in the LM of the 2-3 mm group. In addition, elastin expression in the CFS was markedly higher compared with that in the LM in both groups (in the 0-1 mm group, P=0.005; in the 2-3 mm group, P=0.009). Additionally, the curative effect evaluation revealed that the good correction rates in the 0-1 and 2-3 mm groups were 90 and 100%, respectively. In total, 3 patients experienced conjunctival prolapse during the follow-up period, including 2 patients in the 0-1 mm group and 1 patient in the 2-3 mm group, but there were no other complications. To conclude, elastin expression in the CFS was found to be higher compared with that in the LM of children with severe congenital ptosis. Although elastin expression in the LM was positively associated with LM strength, its expression in the CFS displayed no clear association with LM function. Therefore, these observations suggested that CFS + LM complex suspension surgery is viable to correct severe congenital ptosis in pediatric patients.Copyright: © 2024 Jia et al.