Abstract
Purpose :
To assess the surgical efficacy and safety of a master-slave telemanipulation robotic device (Preceyes BV, Eindhoven, the Netherlands) used to inject a therapeutic drug, recombinant tissue plasminogen activator (rt-PA), under the retina in order to displace sight-threatening haemorrhage.
Methods :
Six patients with acute submacular haemorrhage were recruited for subretinal rt-PA injection and randomised to either robot (n = 3) or standard (n = 3) surgery. The robotic device consisted of a 4-axis motion controller for hand motion input by the surgeon, and a 4-axis instrument manipulator/holder that enabled instrument movement. Following 23 gauge standard vitrectomy, a Teflon-tipped retractable 41 G cannula (DORC BV, Zuidland, the Netherlands) connected to a 1 ml Luer lock syringe containing 200 µg/ml of rt-PA (Alteplase, Boehringer Ingelheim, Germany) was mounted on the instrument manipulator (robot group), or was handheld (standard group), and connected to the viscous fluid control (VFC) port of the Alcon Constellation Vision System (Alcon, Fort Worth, USA). Injection of 0.025 to 0.10 ml of subretinal rt-PA was performed adjacent to the submacular haemorrhage.
Results :
The instrument manipulator was used to move the cannula tip towards the retinal surface under visual and intra-operative OCT guidance (Zeiss Rescan 7000, Carl Zeiss Meditec AG, Jena, Germany). Incremental advancements in the z-axis were performed to a pre-defined depth consistent with retinal thickness (~250 µm) before initiation of subretinal injection. The injection durations (min:sec) were 8:31 and 3:12 for the robot group and 4:00, 6:32 and 4:22 for the control group. In one of the three patients who received robot-assisted rt-PA injections, transient intra-operative exacerbation of cataract precluded a clear view of the cannula tip against the retina and the injection was completed manually.
Conclusions :
Using the virtual z-axis boundary, tremor filtering and clutch mechanism to freeze instrument position, the Preceyes robot allowed precision delivery of a drug into the delicate subretinal tissue plane. This provides proof-of-principle for future applications including robotic assisted delivery of sub-retinal gene therapy.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.