Abstract
Purpose :
Standardized tools do not exist to monitor volumetric or morphological changes in the periorbital region and ocular adnexa due to pathology such as oculofacial trauma, thyroid eye disease, and the natural aging process. We, therefore, developed a low-cost, 3D printed hybrid device and technique to quantifiably evaluate 3-dimensional oculofacial volumetric changes.
Methods :
Images were taken using two Google Pixel 3 smartphones, which were attached to automatic rotating platforms using 3D printed mounts. The platforms were attached to height-adjustable poles with an 18 in and 10 in ring light. Cameras were centered 1.5 ft from the face at eye-level and their rotating axes angled at 12.5 degrees from center (Fig 1A). Subjects placed their faces through a foam backdrop with checkered squares, which were used as image registration landmarks (Fig. 1B). Subjects were instructed to remain motionless during the 60 seconds of image acquisition. Images with and without 3D printed phantom lesions (black domes) affixed above the brow were acquired. Images were processed in Metashape (Agisoft, St. Petersburg, Russia), a 3D reconstruction software. 3D rendered objects were then imported into Autodesk’s Meshmixer where 3D facial renders were registered to each other (Fig. 1C-E). Digitally reconstructed 3D dome volumes were then measured within Meshmixer and compared to their respective calculated volumes. Calculations were based on dome diameters measured with a micrometer.
Results :
3D renderings of the ocular adnexa for 3 subjects were achieved using 60 photos acquired on our custom designed hardware. Differences between calculated and digitally analyzed volumes of 3D printed phantom lesions showed a percent difference of 2.33 ± 2% for 2060 μL, 4.79 ± 2% for 244 μL, and 25 ± 17% for 27.5 μL. Digitally measured phantom lesion volumes were accurate to within 6.8% of the calculated volumes as small as approximately 250 μL; small dome volumes were digitally undermeasured about 25%.
Conclusions :
We demonstrated a technique using a 3D printed hybrid device to analyze and quantify oculofacial volumetric changes with a resolution of approximately 250 μL.
This is a 2021 ARVO Annual Meeting abstract.