Objective To evaluate the effect of dexmedetomidine on the intraocular pressure during laparoscopic gastrectomy.Methods Forty ASA physical status Ⅰ or Ⅱ patients of both sexes,aged 34-64 yr,weighing 45-81 kg,scheduled for elective laparoscopic gastrectomy,were randomly divided into 2 groups with 20 patients in each group using a random number table:control group (group C) and dexmedetomidine group (group D).In group D,a loading dose of dexmedetomidine 1.0 μg/kg was infused intravenously over 15 min,followed by continuous infusion of dexmedetomidine at 0.4 μg·kg-1 · h-1 until the end of surgery.In group C,normal saline 0.25 ml/kg was infused intravenously over 15 min,followed by continuous infusion of normal saline at 0.1 ml·kg-1 · h-1 until the end of surgery.Anesthesia was induced with propofol,sufentanil and rocuronium.After tracheal intubation,intermittent positive pressure ventilation was carried out.PET CO2 was maintained at 33-36 mmHg.Anesthesia was maintained with sevoflurane,propofol,cisatracurium and sufentanil.The pressure of carbon dioxide insufflation was maintained at 9-14 mmHg and airway pressure was maintained at 11-23 cmH2O.Intraocular pressure was measured at 5 min after intubation (T1),at 5,30 and 60 min of pneumoperitoneum (T2-4),and at 5,30 and 60 min after pneumoperitoneum (T5-6).Results Compared with the value at T1,intraocular pressure was significantly increased at T2-6 in group C,and intraocular pressure was increased at T3-5 in group D.Intraocular pressure was significantly lower at T3-5 in group D than in group C.Conclusion Dexmedetomidine can decrease the intraocular pressure during laparoscopic gastrectomy.