The Sedative Effects of Dexmedetomidine VS Propofol During Peribulbar Anesthesia in Patients Undergoing Vitrectomy Surgery

Patients will receive dexmedetomidine at a dose of 0.5-1.0 mcg/kg over 5-10 minutes, then a maintenance infusion rate of 0.2-0.5 mcg/kg/min when the bispectral index (BIS) value is between 70 and 80.

Patients will receive propofol at a dose of 0.25-0.5 mg/kg over 5-10 minutes, then a maintenance Infusion rate of 0.5-2 mg/kg/hr when the bispectral index (BIS) value is between 70 and 80.