In-human feasibility and safety of subretinal drug injection through attached retina using a robotic comanipulation system

Purpose: To evaluate feasibility and safety of robot-assisted subretinal injections through attached retina using the comanipulated Mynutia system in patients with submacular hemorrhage (SMH). Methods: This prospective, single-center case series included 20 eyes undergoing vitrectomy with subretinal recombinant tissue plasminogen activator between June 2024 and August 2025. The EVA Inicio™ microinjection system with a 38G needle was mounted on the Mynutia system. Injections were performed through attached retina when feasible. Primary outcomes were successful needle insertion, stable subretinal positioning for ≥3 minutes, safe withdrawal, and absence of device-associated adverse events (DAE). Secondary outcomes included injection parameters, hemorrhage displacement, visual outcomes, and complications. Results: Robot-assisted injection succeeded in all eyes; one required injection into the SMH due to anatomy. Mean injection duration was 178 ± 34 s (max 400), but the needle tip was maintained in the subretinal space ≥3 minutes in all cases. No DAE occurred. Retinotomies closed spontaneously without visible reflux. Mean bleb initiation and propagation pressures were 10.3 ± 3.2 and 3.0 [3.0–3.25] PSI, respectively; internal limiting membrane peeling reduced initiation pressure (p < 0.05). Complete subfoveal displacement was achieved in 95%. Median BCVA improved from LogMAR 1.85 (counting fingers) to 0.66 (20/90) at 6 weeks (p < 0.001). Adverse events included hyphema (5%), ocular hypertension (5%), vitreous hemorrhage (25%; 80% self-limited), RPE tear (20%), and recurrent SMH (5%). Conclusions: Robot-assisted subretinal injection with Mynutia is feasible and safe, enabling stable, prolonged low-pressure delivery through attached retina, and may enhance precision and tissue preservation in subretinal therapies.