Efficacy of a premedication with melatonin during cataract surgery under peribulbar block: Study protocol for a prospective randomized double-blinded study.

Introduction: Cataract is a ubiquitous pathology. Its prevalence increases with age. Nowadays, cataract surgery is increasingly performed on an outpatient basis under locoregional anesthesia. In this context, sedation-analgesia is essential but not without risks. Aim : To evaluate the effectiveness of premedication with melatonin on intraoperative sedation-analgesia. Methods: This is a prospective randomized double-blind study including patients proposed for scheduled cataract surgery by phacoemulsification under peribulbar anesthetic block. The participants will be randomized into two groups: group (M) will receive 05 tablets of melatonin (10mg sublingual) and group (P) will receive 05 tablets of Sucralose sublingually. Perioperative sedation-analgesia will be evaluated by the Ramsey score, the bisectral index, the simple verbal scale (EVS) and by the perioperative consumption of midazolam and alfentanyl. Secondary endpoints will be the degree of preoperative anxiety (Amsterdam Preoperative, Anxiety and Information Scale), the perioperative tonus of the eyeball, intraoperative nicardepine consumption and patients and surgeons satisfaction. A value of p<0.05 will be considered statistically significant. Expected results : The administration of melatonin as a premedication for scheduled cataract surgery will allow a better quality of intraoperative sedation-analgesia, a reduction in the doses consumed of midazolam and alfentanyl, improves surgical conditions, leads to a decrease in ocular tone, and optimizes surgical safety conditions for the patient.