Computed tomography-based 3D modeling to provide custom 3D-printed glasses for children with craniofacial abnormalities

Using a Smartphone 3-Dimensional Surface Imaging Technique to Manufacture Custom 3-Dimensional-Printed Eyeglasses

Importance

Finding a suitable fit in glasses for pediatric patients with congenital and acquired craniofacial abnormalities is difficult; consequently, these children are at high risk of vision loss secondary to refractive amblyopia as they often have poor adherence to daily glasses wearing. Custom 3-dimensional (3D)-printed glasses may have an improved design and fit, but access is limited by the availability of computed tomography and magnetic resonance imaging (MRI).

Objective

To describe a method for using a commercially available smartphone 3D surface imaging (3DSI) technique to capture facial anatomy as a basis for custom glasses design.

Design, Setting, and Participants

This quality improvement study analyzes data from a case series in a primary academic center with multiple referral centers throughout the United States. The evaluation included reported fit descriptions from patients with poor glasses adherence due to craniofacial abnormalities.

Main Outcomes and Measures

Key anatomic parameters for glasses fit (face width, distance from ear bridge to nasal bridge, distance from center of pupil to center of nasal bridge, distance from lateral to medial canthus, ear vertical offset, and nasal bridge width) were compared between scans. A 3DSI scan was considered successful if these key parameters could be determined and the difference in measurements was less than 5% between MRI and 3DSI. A second outcome measure included the fit of glasses designed by the 3DSI method as reported by the patient, parent, or guardian.

Results

Measurements of key parameters for glasses fit were similar across MRI and 3DSI scans with a mean (SD) difference of 1.47 (0.79) mm between parameters (range, 0.3-4.60 mm). Among 20 patients aged 1 to 17 years with craniofacial abnormalities, all achieved a successful fit (reporting daily glasses adherence without irritation) as judged by the patient, parent, or guardian. A mean of 1.7 revisions were made from initial prototype to final frame production using 3DSI technology.

Conclusions and Relevance

This study demonstrated that smartphone-enabled 3DSI coupled with widely available 3D printing technology can produce custom frames with a successful fit for patients with craniofacial anomalies. This accessible and well-tolerated imaging process may have implications for adherence with glasses wearing among patients at risk of vision loss due to amblyopia.

Three-dimensional printing in ophthalmology and eye care: current applications and future developments

Three-dimensional (3D) printing uses a process of adding material in a layer-by-layer fashion to form the end product. This technology is advancing rapidly and is being increasingly utilized in the medical field as it becomes more accessible and cost-effective. It has an increasingly important role in ophthalmology and eyecare as its current and potential applications are extensive and slowly evolving. Three-dimensional printing represents an important method of manufacturing customized products such as orbital implants, ocular prostheses, ophthalmic models, surgical instruments, spectacles and other gadgets. Surgical planning, simulation, training and teaching have all benefitted from this technology. Advances in bioprinting seem to be the future direction of 3D printing with possibilities of printing out viable ocular tissues such as corneas and retinas in the future. It is expected that more ophthalmologists and other clinicians will use this technology in the near future.

A review of additive manufacturing applications in ophthalmology

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.