A prospective, one-center clinical trial to identify the safety and feasibility of sutureless pars-plana vitrectomy performed in sub-tenon anesthesia.

In Germany pars-plana vitrectomies are mostly performed in general anesthesia. This requires the immediate availability of a trained anesthesiology team, which is not always granted, especially in urgent eye disease (i.e. endophthalmitis, high risk retinal detachment). Furthermore, some patients are not suitable for general anesthesia due to systemic diseases (i.e. cardio-vascular diseases). There are several procedures of local ocular anesthesia (i.e. peribulbar, retrobulbar, sub-tenon anesthesia). The main advantage of sub-tenon anesthesia is the use of a blunt cannula limiting the risk of potential complications.

The purpose of this study is to investigate the safety of local sub-tenon anesthesia procedure for sutureless vitrectomy (anesthetic mixture: 2ml xylocaine and 2ml bupivacaine) in a prospective clinical study design.

Primary outcome: The evaluation of 1. sensation of pain, 2. patients' intraoperative discomfort and 3. visual sensations using the standardized questionnaires (WONG-BAKER Faces Scale, Visual Analog Scale and individual questions).

Secondary Outcome: The evaluation of 1. chemosis, 2. eye movement, 3. surgeon's general feeling of comfort during surgery (rating scale).