Abstract
Purpose :
Craniofacial malformations are part of a broad range of congenital abnormalities and syndromes. Frequently these include ocular pathology and refractive error. Treating the refractive error, and in young patients preventing amblyopia, is challenging as due to their irregular facial anatomy, standard spectacles are ill fitting. Previously we have reported developing a novel method for overcoming this challenge by reconstructing computed tomography (CT) scans to develop an anatomic model upon which customized spectacles can be designed and then 3D printed. This method was limited by the availability of prior CT scans and how accurately they reflected the child’s current anatomy. To overcome this, we developed a custom iPhone (Apple, Cupertino, CA) application which utilizes the RGB-D infrared camera to create a 3D model of the patient’s head. This file can then be sent for glasses design and printing.
Methods :
The iOS application uses the Standard Cyborg SDK (Standard Cyborg Inc, San Francisco, CA) which enables extremely accurate on-device real-time 3D scanning using the iPhone Truedepth Sensor. The Truedepth sensor is an infrared projector and camera that projects 30,000 dots at 30 frames a second. The raw depth data from the sensor passes through Standard Cyborg's Simultaneous Location and Mapping (SLAM) pipeline to build up a 3D model. This enables the user to capture a 3D scan of the patient directly from their phone that can be used for creating custom eyewear.
Results :
We have successfully produced glasses for children with a range of craniofacial malformations including microtia, Apert syndrome and Crouzon syndrome. Using the app we have eliminated the need for “upsizing” or increasing all the measurements from a CT derived model based on growth since the CT. We reduced the number of design revisions from on average 4 to 2 and decreased turnaround time from 6 to 2 months.
Conclusions :
iPhone based 3D scanning greatly improves our ability to provide custom 3D glasses through improved ease of use, access, and by providing up to date anatomic models. We plan to use this new technology to develop automated measurements in conjunction with parametric modeling to begin automation of the design in the future. We hope these advances will enable increased availability of this technology for all patients who need customized spectacle frames due to non-standard anatomy.
This is a 2020 ARVO Annual Meeting abstract.