Phase I trial on robot assisted retinal vein cannulation with ocriplasmin infusion for central retinal vein occlusion

Purpose To evaluate the safety and feasibility of robot-assisted retinal vein cannulation with Ocriplasmin infusion for central retinal vein occlusion. Methods Prospective phase I trial including four patients suffering from central retinal vein occlusion (CRVO). Diagnosis was confirmed by preoperative fluo-angiography and followed by a standard three-port pars plana vitrectomy. Afterwards, a custom-built microneedle was inserted into a branch retinal vein with robotic assistance and infusion of Ocriplasmin started. Primary outcomes were the occurrence of intra-operative complications and success of cannulation. Secondary outcomes were change in visual acuity, central macular thickness (CMT) and venous filling times (VFT) during fluo-angiography two weeks after the intervention. Results Cannulation with infusion of ocriplasmin was successful in all four eyes with a mean total infusion time of 355 +/- 204 seconds (range 120-600 seconds). Best corrected visual acuity (BCVA) remained counting fingers (CF) in case 3 and 4, increased in case 1 from CF to 0.9LogMAR and decreased in case 2 from 0.4 to 1.3 LogMAR. CMT and VFT both showed a trend towards significant decrease comparing preoperative measurements with two weeks postintervention (1061 +/- 541 mu m versus 477 +/- 376 mu m, p = 0.068) and 24 ll 4 seconds versus 15 +/- 1 seconds, p = 0.068, respectively). In one eye a needle tip broke and could be removed with an endoforceps. There were no other intervention-related complications. Conclusion Robot-assisted retinal vein cannulation is feasible and safe. Local intravenous infusion with Ocriplasmin led to an improved retinal circulation.