Ultrasonographic study of the eyelids in patients with paralytic lagophthalmos: parallels between clinical signs and anatomy

Purpose. To establish parallels between clinical signs and anatomy based on the ultrasonographic examination in patients with paralytic lagophthalmos. Material and methods. This study included 31 patients (24 females and 7 males) aged 27–79 years with monolateral paralytic lagophthalmos. In all patients, thicknesses of the upper and lower eyelid are: skin, orbicularis oculi muscle including Riolan’s muscle, upper eyelid levator with Muller’s muscle, tarsus, conjunctiva, as well as total eyelid thickness. The measured parameters on the side with lagophthalmos were compared with ones on the fellow intact side. Results. In paralytic lagophthalmos, we found out differences in the thickness of the upper and lower eyelid structures. In the lower eyelid on the side with lagophthalmos, all measured structures were thinner. Additionally, there was no significant difference at the ratio between Riolan’s muscle and orbicularis oculi muscle thicknesses. In the upper eyelid, most of the structures were thinned, along with thickening of skin, tarsus and complex of tarsus and conjunctiva. Moreover, the ratio between thickness of levator with Muller’s muscle and orbicularis oculi muscle increased multiple times. This is due to the thinning of orbicularis oculi muscle. On the contralateral intact side, the studied structures were noticed to be thicker in the lower eyelid than in the upper one. Conclusion. Thus, the article provides the strong anatomical ground for the typical clinical signs of lagophthalmos: upper eyelid retraction and lower eyelid ectropion. Key words: facial nerve palsy, orbicularis oculi muscle, levator, Muller’s muscle, Riolan’s muscle, cornea, upper eyelid retraction, ectropion, eyelids ultrasound examination