Refillable Drug Reservoirs for Retinal Vascular Diseases

Purpose: Most patients with retinal vascular disease require chronic, regular treatments to maximize visual potential. This places a challenging burden on the patient and is one reason why real-world visual outcomes often lag the results seen in clinical trials.

Methods: Sustained drug delivery devices have long been considered one way to alleviate this difficulty. Devices with refillable reservoirs aim to take advantage of existing drugs to improve their pharmacokinetics and reduce treatment frequency. Few devices using a refillable reservoir have reached human clinical trials, however. Only one, the port delivery system (PDS) with ranibizumab, has received approval by the U.S. Food and Drug Administration. Despite this milestone, the PDS was voluntarily withdrawn 1 year after its introduction because of product quality challenges related to the septum of the device. The PDS was recently returned to the market after modifications to the implant as well as the refill-exchange needle.

Conclusion: Although devices with refillable reservoirs have increased challenges related to their inherent complexity, the potential for improved patient outcomes merit further development of this technology.