Levator resection for congenital ptosis: Does pre-operative levator function or degree of ptosis affect successful outcome?

The aim of this study was to determine whether pre-operative levator function and degree of ptosis affect surgical outcomes in children with congenital ptosis undergoing anterior levator resection under general anaesthesia. Retrospective cohort study. Children with 'simple' congenital ptosis who underwent anterior levator resection under general anaesthesia. Consecutive cases were reviewed with regards to achievement of the desired lid height (surgical success), and the influence of preoperative levator function and degree of ptosis. The amount of pre-operative levator function and degree of ptosis, with corresponding surgical outcomes. Forty-two lids (37 patients) were included in the study: 36 primary and 6 revision cases (which were excluded from analysis due to small sample size). Mean age was 7 years (range 3-17 years), with similar male to female ratio (1.2:1). The overall success rate for primary was 86%. There were small to moderate trends towards greater amount of levator resection for lower levator function (r = -0.25, p < 0.05) and higher degree of ptosis (r = 0.38, p < 0.05). All successful primary cases (n = 31) had pre-operative levator function of at least 8 mm. Levator resection in children under general anaesthesia continues to be an imprecise science. Degree of ptosis and levator function were poorly correlated to each other; however, there was an expected small to moderate correlation between resection amount and levator function (negative correlation) or degree of ptosis (positive correlation). Patients with levator function of 8mm or more are likely to have a successful outcome.