A low-cost, tunable suprachoroidal injection platform with real-time OCT guidance for gene therapy delivery

Gene therapy shows considerable promise for treating vision impairments, including retinitis pigmentosa (RP), age-related macular degeneration (AMD), and diabetic retinopathy (DR). Current delivery methods, such as subretinal, intravitreal, and conventional suprachoroidal injections, are effective but pose significant challenges, including inflammation and complications that hinder their clinical translation. In this study, we present an integrated suprachoroidal injection (SCI) platform that combines a low-cost, tunable needle design with real-time optical coherence tomography (OCT) guidance for precise and safe suprachoroidal delivery. The injection device is constructed from a standard insulin syringe fitted with an adjustable silicone sheath that enables rapid and continuous control of needle penetration depth, eliminating the need for complex nested-needle assembly used in prior approaches. Real-time spectral-domain OCT imaging was incorporated to dynamically monitor needle positioning and confirm suprachoroidal delivery. In vivo studies in rabbits demonstrated accurate delivery of indocyanine green (ICG) and adeno-associated virus (AAV) vectors without ocular or systemic toxicity. Furthermore, AAV delivery exhibited dose-dependent transgene expression over 28 days, validating the platform for gene therapy applications. Compared with existing microneedle and catheter-based systems, this approach offers a simplified, scalable, and cost-effective alternative while maintaining precision through imaging guidance. This combined platform provides a practical solution for suprachoroidal drug delivery and facilitates broader adoption in both preclinical and translational research.