Vitreoretinal surgery is associated with a considerable incidence of postoperative nausea and vomiting (PONV), which is reported to be as high as 60%. Reasons for this high incidence may be the long duration of surgery and anesthesia and the high degree of manipulation of the eye. Postoperative vomiting after vitrectomy is an important risk factor for the onset of several complications, such as suprachoroidal hemorrhage, with disastrous visual consequences.

To date there is no evidence as to the possible protective effect of anti-emetic therapy with regard to interventions of vitrectomy performed under local anesthesia.

In this prospective, randomized, multicenter, double blind study, we evaluated the efficacy of Ondansetron alone, Dexamethasone alone and in combination in controlling nausea and vomiting in patients undergoing vitrectomy under local anesthesia.

Patients were randomly stratified to receive 1 of 4 prophylactic antiemetic treatments (3 pharmaceutical treatment and 1 placebo) in a double-blind manner at the start of the surgery and 15 minutes before the end of surgery.

The syringes were prepared by a third, neutral person not involved in the perioperative care of the patient, immediately before the start of anesthesia.

All vitrectomy surgeries were performed, in each unit,under local anesthesia by a retrobulbar block.

Each patients was observed and treated during a period of 24 hours after the surgery. For patients who have nausea and vomiting despite the antiemetic prophylaxis, will be given a rescue dose of 4 mg ondansetron IV.

Inclusion Criteria:

• Age 18 or older with an American Society of Anesthesiologists (ASA) physical status of I to II
• Scheduled for vitrectomy under local anesthesia

Exclusion Criteria:

• Hypersensitivity to study drug or rescue medication
• Preoperative score for nausea greater than 4 out of 10 points
• Subjects who suffer from chronic nausea and/or vomiting
• Severe hepatic insufficiency (Child-Pugh score > 9)
• Other antiemetic within 12 hours prior to surgery
• Patients unable to undergo a local anesthetic
• Subjects with clinically significant or unstable cardiac, respiratory, hepatic, renal, or other major organ system disease
• Psychotic illness or depression
• Addiction to illicit substances or alcohol
• Non-psychotic emotional disorders
• Pregnant or lactating
• Subjects who, in the opinion of the investigator, would experience an unacceptable risk from administration of study drug