[Etiologic causes of ptosis about a serie of 484 cases. To a new classification?].

We have analyzed the etiological causes of ptosis in a retrospective study of 484 cases undergoing operation. This study has confirmed how difficult it is to classify ptosis despite the different existing classifications. Some authors divide ptosis into two groups: congenital and acquired. These classifications seem to have been abandoned now for classifications based on the mechanism that instigates ptosis rather than the moment when the deficit developed. We chose to classify ptosis into five subgroups: myogenic (42% of the cases studied), aponeurotic (35.3%), neurogenic (6.8%), mixed (15.9%), and pseudoptosis (enophthalmos, eyelid tumor, hypotropia, etc.), the latter of which were removed from this series. This classification is based on clinical and surgical criteria. It has the advantages of unity, simplicity, and practicality in terms of establishing a treatment plan for a given ptosis patient. Indeed, each subgroup requires a particular clinical examination and a more stereotyped surgical treatment.