Ultrasound-based histological differences in thickness between puffy eyelids and normal eyelids in Asian monolid women.

[BACKGROUND] Upper eyelid tissue swelling is a common characteristic among Asian monolid individuals and is associated with a high incidence of complications following eyelid surgery. Currently, there is no precise definition for upper eyelid tissue swelling; thus, further research is required to elucidate the specific causes contributing to upper eyelid puffiness.

[METHOD] Between June 2023 and February 2024, we recruited 84 Asian monolid women categorized into groups based on the severity of upper eyelid tissue swelling: the puffy eyelid group and normal eyelid group. High-frequency ultrasound was employed to capture images of the upper eyelids and measure the thickness of various tissue layers. This study aimed to conduct a comparative analysis to identify the factors contributing to upper eyelid fullness, focusing on elucidating the underlying causes of this condition.

[RESULT] All volunteers underwent bilateral upper eyelid ultrasound imaging. Significant differences were observed in the thickness of subcutaneous fat, pre-tarsal fat, retro-orbicularis oculi fat (ROOF), and composite fat (ROOF and preaponeurotic fat) layer between the puffy and normal eyelid groups. However, no significant differences were found in skin thickness or orbicularis oculi muscle thickness. Additionally, no significant differences were observed in the thickness of various layers of the upper eyelid tissue between the left and right eyes in all participants.

[CONCLUSION] Thickening of the upper eyelid fat layer is a primary cause of upper eyelid puffiness. In upper blepharoplasty, targeted removal of preaponeurotic fat, ROOF, and pre-tarsal fat can achieve precise reduction to correct upper eyelid puffiness effectively.