Randomised controlled trial on robot-assisted versus manual surgery for pucker peeling.

BACKGROUND: The aim was to explore the feasibility and safety of performing common surgical steps in epiretinal membrane (ERM) peeling using the Preceyes Surgical System (PSS). METHODS: In a tertiary centre, 15 pseudophakic patients with an idiopathic ERM were randomised to robot-assistance or manual surgery in a 2:1 ratio. In the robot-assisted group, the following steps were performed using PSS: (1) staining the internal limiting membrane (ILM), (2) removal of the dye, (3) creating an ILM flap, (4) completing the peeling, (5) holding a light pipe and (6) fluid-air exchange. Primary outcome measures were feasibility and safety. Secondary outcome measures were duration, best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Moreover, the distance travelled by the instrument during peeling was assessed using motion tracking software. RESULTS: All steps performed with PSS were feasible with no clinical adverse events or complications. The surgical time was longer in the robot-assisted group (mean 56 min, SD = 12 vs. 24 min, SD = 5). During the study, the duration of robot-assisted surgeries decreased from 72 to 46 min. The distance travelled by the forceps was shorter in the robot-assisted group (mean 403 mm, SD = 186 vs. 550 mm, SD = 134). BCVA and CRT improved equally in both groups. CONCLUSIONS: This is the world's first randomised controlled trial on robotic surgery for ERM. Although more time-consuming, we found that several surgical steps were feasible with assistance of the PSS.

First-in-Human Robot-Assisted Subretinal Drug Delivery Under Local Anesthesia.

PURPOSE: To report the results of a first-in-human study using a robotic device to assist subretinal drug delivery in patients undergoing vitreoretinal surgery for macular hemorrhage. DESIGN: Double-armed, randomized controlled surgical trial (ClinicalTrials.gov identifier: NCT03052881). METHODS: The study was performed at the Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom. In total, 12 participants were recruited-6 in the robot-assisted and 6 in the control manual surgery arm according to the prespecified inclusion and exclusion criteria. All subjects presented with acute loss of vision owing to a subfoveal hemorrhage secondary to neovascular age-related macular degeneration. After standard vitrectomy, intraoperative optical coherence tomography-guided subretinal injection of tissue plasminogen activator (TPA) was performed by either robot-assisted or conventional manual technique under local anesthesia. The robotic part of the procedure involved advancement of a cannula through the retina and stabilizing it during foot-controlled injection of up to 100 µL of TPA solution. We assessed surgical success, duration of surgery, adverse events, and tolerability of surgery under local anesthesia. RESULTS: The procedure was well tolerated by all participants and safely performed in all cases. Total duration of surgery, time taken to complete the injection, and retinal microtrauma were similar between the groups and not clinically significant. Subretinal hemorrhage was successfully displaced at 1 month postintervention, except for 1 control subject, and the median gain in visual acuity was similar in both arms. CONCLUSIONS: This first-in-human study demonstrates the feasibility and safety of high-precision robot-assisted subretinal drug delivery as part of the surgical management of submacular hemorrhage, simulating its potential future application in gene or cell therapy.

Robotic-assisted surgery in ophthalmology.

PURPOSE OF REVIEW: Provide an overview of the current landscape of robotics in ophthalmology, including the pros and cons of system designs, the clinical development path, and the likely future direction of the field. RECENT FINDINGS: Robots designed for eye surgery should meet certain basic requirements. Three designs are currently being developed: smart surgical tools such as the steady hand, comanipulation devices and telemanipulators using either a fixed or virtual remote center of motion. Successful human intraocular surgery is being performed using the Preceyes surgical system. Another telemanipulation robot, the da Vinci Surgical System, has been used to perform a pterygium repair in humans and was successful in ex-vivo corneal surgery despite its nonophthalmic design. Apart from Preceyes' BV research platform, none of the currently eye-specific systems has reached a commercial stage. Systems are likely to evolve from robotic assistance during specific procedural steps to semiautonomous surgery, as smart sensors are introduced to enhance the basic functionalities of robotic systems. SUMMARY: Robotics is still in its infancy in ophthalmology but is rapidly reaching a stage wherein it will be introduced into everyday ophthalmic practice. It will most likely be introduced first for demanding vitreo-retinal procedures, followed by anterior segment applications.

Release of experimental retinal vein occlusions by direct intraluminal injection of ocriplasmin.

PURPOSE: Retinal vein occlusions (RVO) are a major cause of vision loss in people aged 50 years and older. Current therapeutic options limit the consequences of RVO but do not eliminate the cause. Cannulation of the involved vessel and removal of the clot may provide a more permanent solution with a less demanding follow-up. However, cannulation of smaller retinal veins remains challenging. This paper explores the use of ocriplasmin (recombinant plasmin without its kringles) to clear RVO, using a robotic micromanipulator. METHODS: Branch RVO were induced in a porcine model with rose bengal followed by 532 nm endolaser to the superior venous branch of the optic nerve. The vein was cannulated proximal to the occlusion or beyond the first branching vessel from the obstruction. The vein was infused with a physiologic citric acid buffer solution (CAM) or CAM/ocriplasmin. The time of cannulation, number of attempts, and the ability to release the thrombus were recorded. RESULTS: Cannulation and infusion was possible in all the cases. The use of a micromanipulator allowed for a consistent cannulation of the retinal vein and positional stability allowed the vein to remain cannulated for up to 20 min. In none of the attempts (5/5) with CAM did the thrombus dissolve, despite repeat infusion/relaxation cycles. In 7/7 injections of CAM/ocriplasmin near to the point of obstruction, the clot started to dissolve within a few minutes of injection. An infusion, attempted beyond the first venous branch point proximal to the clot, was unsuccessful in 2/3 attempts. CONCLUSIONS: Ocriplasmin is effective in resolving RVO if injected close to the site of occlusion with the use of a micromanipulator.

Robotic Assisted Cannulation of Occluded Retinal Veins.

PURPOSE: To develop a methodology for cannulating porcine retinal venules using a robotic assistive arm after inducing a retinal vein occlusion using the photosensitizer rose bengal. METHODOLOGY: Retinal vein occlusions proximal to the first vascular branch point were induced following intravenous injection of rose bengal by exposure to 532nm laser light delivered by slit-lamp or endolaser probe. Retinal veins were cannulated by positioning a glass catheter tip using a robotically controlled micromanipulator above venules with an outer diameter of 80µm or more and performing a preset piercing maneuver, controlled robotically. The ability of a balanced salt (BSS) solution to remove an occlusion by repeat distention of the retinal vein was also assessed. RESULTS: Cannulation using the preset piercing program was successful in 9 of 9 eyes. Piercing using the micromanipulator under manual control was successful in only 24 of 52 attempts, with several attempts leading to double piercing. The best location for cannulation was directly proximal to the occlusion. Infusion of BSS did not result in the resolution of the occlusion. CONCLUSION: Cannulation of venules using a robotic microassistive arm can be achieved with consistency, provided the piercing is robotically driven. The model appears robust enough to allow testing of therapeutic strategies aimed at eliminating a retinal vein thrombus and its evolution over time.