A novel standardized approach for the 3D evaluation of upper eyelid area and volume.

This is the first study to propose a standardized upper eyelid region selection strategy and simultaneously validate its reliability for 3D areal and volumetric measurements. This study confirmed the high-level reliability of areal measurement and poor reliability of volumetric measurement based on direct measurements using a single image, which may provide better results when this method is combined with the image overlapping and registration procedure. However, this is subject to further validation. Nonetheless, this method could provide quantitative areal and volumetric data on the upper eyelids and might have widespread application potential in the future.