3D Printed Adjustable Glasses: A New Model for Corrective Lens Delivery for Pediatric Refractive Error in Underserved Communities

Background: Uncorrected refractive error (URE) remains a major cause of preventable vision impairment in the pediatric population with large inequities in disease burden. The present study aims to elucidate the global burden of pediatric URE and explore the current lens delivery systems which address this problem. Within this framework, we introduce a new model of corrective lens delivery that may improve upon existing models.

Methods: The present study involved an extensive literature review of epidemiological data to determine the global prevalence of pediatric URE. Prevalence data was then compared against WHO data on refractionist coverage gaps divided by region. Four current models for corrective lens delivery, plus a newly proposed model, were compared across three general categories (Fit, Pathologies Corrected, Cost to Patient).

Results: In children, the estimated pooled prevalence (EPP) of myopia, hyperopia, and astigmatism was 11.7% (95% CI: 10.5–13.0), 4.6% (95% CI: 3.9–5.2), and 14.9% (95% CI: 12.7–17.1), respectively. The highest prevalence of astigmatism and hyperopia occurs in The Americas at double and triple the global average respectively. The regions with the poorest coverage of URE were Sub-Saharan Africa, Southeast Asia and The Americas. Existing solutions delivering coverage to these underserved areas often lacks the ability to correct for astigmatism. The newly proposed, modular glasses design provides a one-size-fits-all frame with circular lens mounts to accommodate any axis of astigmatism. 3D printed materials allow these frames to be constructed at a fraction of the cost of conventional frames.

Conclusion: While corrective lenses are made available through a variety of distribution models, the infrastructure to fit and deliver these glasses to remote and resource poor areas remains a major challenge leading to inequities in pediatric URE treatment. The flexibility of the new glasses design allows for these glasses to be distributed in rural and urban environments alike, with minimal training required to fit and assemble, at a low cost to patients.