Anthropometric analysis of levator muscle function.

Abstract

Measurement of levator muscle function is very important in the evaluation and choice of surgical methods for blepharoptosis. In addition, the functional values of levator muscles are very helpful in cases of bilateral ptosis surgery. The normal values of levator muscle function vary according to race, sex, and age. Unfortunately, there are few articles concerning this function in Asians, so the authors have been forced to use Caucasian statistical data in conducting blepharoptosis surgery, until now. There are two commonly used methods for measuring levator muscle function: Berke's method and margin limbal distance. The authors have measured levator muscle function by both of these methods, and have statistically analyzed the function of 498 individuals (234 males and 264 females). The mean levator muscle function values were 11.9 +/- 1.6 mm in males and 11.9 +/- 1.6 mm in females through Berke's method, and 6.5 +/- 1.0 mm in males and 6.6 +/- 1.0 mm in females by margin limbal distance. There was no statistical difference between male and female subjects in left and right levator muscle function. Levator function reached a peak level during the high teen years and twenties among a large percentage of subjects. After peaking, the pattern of change in levator function became stationary or decreased gradually. The results are very different from the reports of Putterman on his Caucasian subjects. Therefore, they should be applied as the standard in cosmetic surgery on Asian eyelids.