Levator Superioris Muscle Function in Involutional Blepharoptosis

Abstract

To assess the role of muscular degeneration, we evaluated the correlation between ptosis severity and levator muscle function. Retrospective cohort study. The medical records of 136 patients (53 men and 83 women; mean age, 67 years) with acquired blepharoptosis were reviewed for levator function (LF), margin reflex distance (MRD), age, and gender. Multivariate linear regression was performed for statistical analysis. A significant correlation (P < .001) was seen between MRD (mean, 1.0 + 1.0 mm; range, -3.0 to 3.0 mm) and LF (mean, 15.0 + 1.0 mm; range, 11.0 to 20.0 mm). On average, a 0.5-mm reduction in LF was observed for each 1.0-mm decrease in MRD. This was independent to other variables assessed. In patients with involutional blepharoptosis, a directly proportional decrease in levator function and eyelid height was observed. This may implicate an abnormality of the levator muscle itself as a contributing factor in the development of involutional blepharoptosis.