Evaluation of a Novel Prefilled Syringe Concept for Ophthalmic Applications: A Formative Human Factors Study

Intravitreal injection (IVI) is the most commonly performed intraocular procedure worldwide. Several manufacturers have developed glass prefilled syringe (PFS) devices to increase the ease of performing IVIs and reduce the complications associated with medication preparation. This formative human factors study assessed a novel, polymer PFS alternative to glass syringes to support development of a usable, silicone-free delivery platform for IVI. Thirteen retina specialists (RSs) with experience preparing a minimum of ≥10 IVIs per week completed the study. RSs were presented with the concept device and prototype instructions for use and completed hands-on tasks to simulate IVI. They then evaluated the concept device for ease of use, comfort, safety, and overall preference versus the IVI devices they are accustomed to using. The primary objectives were to assess the ease of use and acceptability of the proposed syringe design, evaluate the corresponding instructions for use (IFU), and identify any potential usability issues. The secondary objectives were to evaluate a new tamper-evident cap design and compare several externally printed dose marking designs. There were 130 total opportunities for use errors that deviated from the IFU. Of these 130 steps, 110 were a Success, 17 were Incomplete or Incorrect, 2 were Resolved, and 1 was the result of a Study Artifact. All 13 participants completed 3 Essential Tasks successfully and at least 10 participants completed each of the 4 Safety-Critical Tasks successfully. A total of 20 errors were made throughout the test simulation, most of which were rooted in unfamiliar use steps or transference behaviors. Overall, the concept device was found to be usable, acceptable, and safe for IVI by experienced RSs. RSs preferred the concept device to IVI products supplied in vials, but there was no notable preference for the concept device design compared to current glass PFSs used for IVI. The unique features of the concept device, including absence of silicone oil and break-resistance, were mostly recognized by participants and may offer an improvement to currently available systems for IVI.