Comparison of a custom Photogrammetry for Anatomical CarE (PHACE) system with other Low- Cost Facial Scanning Devices.

ABSTRACT

Purpose: To compare a custom Photogrammetry for Anatomical CarE (PHACE) system with other cost-effective 3-dimensional (3D) facial scanning systems to objectively characterize morphology and volume of periorbital and adnexal anatomy. Methods: The imaging systems evaluated include the low-cost custom PHACE system and commercial software product for the iPhone called Scandy Pro (iScandy) application (Scandy, USA), and the mid-priced Einscan Pro 2X (Shining3D Technologies, China) device and Array of Reconstructed Cameras 7 (ARC7) facial scanner (Bellus3D, USA). Imaging was performed on a manikin facemask and humans with various Fitzpatrick scores. Scanner attributes were assessed using mesh density, reproducibility, surface deviation, and emulation of 3D printed phantom lesions affixed above the superciliary arch (brow line). Results: The Einscan served as a reference for lower cost imaging systems because it qualitatively and quantitatively renders facial morphology with the highest mesh density, reproducibility (0.13 ± 0.10 mm), and volume recapitulation (approximately 2% of 33.5 µL). Compared to the Einscan, the PHACE system (0.35 ± 0.03 mm, 0.33 ± 0.16 mm) demonstrated non-inferior mean accuracy and reproducibility root mean square (RMS) compared to the iScandy (0.42 ± 0.13 mm, 0.58 ± 0.09 mm), and significantly more expensive ARC7 (0.42 ± 0.03 mm, 0.26 ± 0.09 mm). Similarly, the PHACE system showed non-inferior volumetric modeling when rendering a 124 µL phantom lesion compared to the iScandy and more costly ARC7 (mean percent difference from the Einscan 4.68 ± 3.73%, 9.09 ± 0.94%, and 21.99 ± 17.91% respectively). Conclusions: The affordable PHACE system accurately measures periorbital soft tissue as well as other established mid-cost facial scanning systems. Additionally, the portability, affordability, and adaptability of PHACE can facilitate widespread adoption of 3D facial anthropometric technology as an objective measurement tool in ophthalmology.