Smartphone 3D Surface Imaging Offers Accessibility to Visually Impaired Pediatric Patients with Craniofacial Abnormalities

For many children, wearing the correct glasses is crucially important to ensuring lifelong, healthy vision. While finding the right prescription or style might be tedious, there are many commercially available glasses to fit the needs of most children. However, for pediatric patients with congenital or acquired craniofacial abnormalities, finding glasses that comfortably fit with their unique cranial anatomy can be a challenge. These children may have poor adherence to wearing glasses daily, and because of this, they are at an increased risk of vision loss secondary to refractive amblyopia.

While traditional glasses pose a challenge to these pediatric patients, custom 3-dimensional (3D) -printed glasses may offer improved comfort and ease of wear for the child. Unfortunately, accessibility is often limited by the availability of computed tomography and magnetic resonance imaging (MRI). A study published in Jama Ophthalmology sought to rectify this inaccessibility by using a commercially available 3D surface imaging (3DSI) technique to capture facial anatomy as a basis for custom glasses design.

A total of twenty patients aged 1 to 17 years with craniofacial abnormalities and poor glasses adherence were included in the study. The patients underwent a commercially available 3DSI via smartphone to be designed customized glasses. 3DSI scans were considered successful if the difference in measurements between MRI and 3DSI was less than 5%.

Key parameters were compared between scans and included 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. A secondary outcome measure was the fit of the glasses as reported by the patient and/or their parent or guardian.

The measurements of key parameters were similar between MRI and 3DSI scans; the mean difference reported between parameters was 1.47 mm. A mean of 1.7 revisions were made from the initial prototype to the final printing of the frame. Perhaps most importantly, all 20 patients achieved a successful fit. Per judgement of either the patient, parent, or guardian, each of the patients were able to report daily glasses adherence without irritation.

The researchers said that the results of this study may have implications for adherence with glasses wearing among patients at risk of vision loss due to amblyopia. “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,” they concluded.