方法：采用随机临床对照研究。随机选择非眼睑相关疾病的病例75例150眼，其中20～39岁(青年组)、40～59岁(中年组)、>60岁(老年组)各25例50眼。其中男30例60眼，女45例90眼。通过超声生物显微镜测量提上睑肌厚度，观察结果并运用统计学方法分析年龄及性别因素对提上睑肌厚度的影响。

结果：经测量三组平均值分别为0.833±0.054、0.723±0.021、0.644±0.037mm。女性与男性的平均值分别为0.748±0.100、0.734±0.078mm。统计学采用单因素方差分析法，结果显示超声生物显微镜检查不同年龄段正常人群的提上睑肌厚度各组间差异有统计学意义(P<0.01)，不同性别人群的提上睑肌厚度差异无统计学意义。

结论：超声生物显微镜是一种便捷、非侵入性且可以比较精确测量提上睑肌厚度的方法。随着年龄增大，即便未患有老年性上睑下垂，提上睑肌厚度也会逐渐变薄，但是提上睑肌的厚度与性别无关。

METHODS:Seventy-five cases(150 eyes)with normal levator palpebrae muscle were collected in our hospital. The normal levator palpebrae muscle was categorized into youth group(aged 20～39), middle-aged group(aged 40～59)and older group(aged >60), 25 cases with 50 eyes in every group. The number of male was 30(60 eyes)and the number of female was 45(90 eyes).UBM was applied to measure the thickness of levator palpebrae muscle of each eye. The results were analyzed statistically and to see if the thickness might be effected by age or gender.

RESULTS:The mean thickness of levator palpebrae muscle in youth group, middle-aged group and older group were 0.833±0.054, 0.723±0.021 and 0.644±0.037mm respectively. The mean thickness was 0.748±0.100mm in females and 0.734±0.078mm in males. By one-way ANOVA, the thicknesses of levator palpebrae muscle among the three different groups were different, and the differences were statistically significant(P<0.01). There was no significant difference on the thickness of the levator muscle between gender.

CONCLUSION:UBM is a covenient,non-invasive test which can be used to measure the thickness of the levator palpebrae muscle. The levator palpebrae muscle becomes thinner gradually as aging, even without senile blepharoptosis, and the gender has nothing to do with the thicknesses of levator palpebrae muscle.