Objective  To compare the thickness of levator aponeurosis by ultrasound biomicroscopy in patients with congenital blepharoptosis and normal persons and analyze its correlative factors.
Methods  Eighty-four upper eyelids of 42 patients who had unilateral or bilateral congenital blepharoptosis and 50 upper eyelids of 25 normal persons were evaluated by ultrasound biomicroscopy randomly. Single factor and multi-factor regression analysis were used to analyze influencing factors of the thickness of levator aponeurosis.
Results  The mean thickness of the levator aponeurosis was 0.30±0.07mm in normal eyelids of normal persons and 0.36±0.10mm in ptotic eyelid of patients with congenital blepharoptosis (p<0.001). The mean thickness of the levator aponeurosis was 0.32±0.09mm in eyelids with normal levator function (≥8mm) and 0.36±0.10mm with weak levator function (＜8mm, p＜0.05). There was no statistically significant of the thickness of the levator aponeurosis in different age front muscle groups (p＞0.05). Multi-factor regression analysis was applied on the thickness of the levator aponeurosis. According to the result, the degree of disease is independently associated with the thickness of the levator aponeurosis (t=-3.800, p<0.001, t=2.499, p=0.014). Otherwise, age, levator function and front muscle fuction did not correlate with it.
Conclusions  The thickness of the levator aponeurosis can be quantified with ultrasound biomicroscopy. The levator aponeurosis in the ptotic eyelid of patients with congenital blepharoptosis is thicker than in the normal eyelid of normal persons. The reason for the thickened levator aponeurosis is the disease factor.