The Effect of Fentanyl versus Buprenorphine on Pupil Size in Cataract Surgery

INTERVENTION: In control group size of the pupil will be measured twice by the surgeon who is unaware of the induction regime. The induction drug in this group is STP 3 g/kg plus atracurium 0.2 mg /kg plus fentanyl 2 mcg/kg. After induction patient will be ventilated by mask and then ventilation will continue by LMA until the end of surgery. Pupil size will be measured 4 minute later by the same surgeon. In intervention group size of the pupil will be measured twice by the surgeon who is unaware of the induction regime. The induction drug in this group is STP 3 g/kg plus atracurium 0.2 mg /kg plus buperonorphinel 0.3 mcg/kg. After induction patient will be ventilated by mask and then ventilation will continue by LMA until the end of surgery. Pupil size will be measured 4 minute later by the same surgeon Intervention 1: In control group size of the pupil will be measured twice by the surgeon who is unaware of the induction regime. The induction drug in this group is STP 3 g/kg plus atracurium 0.2 mg /kg plus fentanyl 2 mcg/kg. After induction patient will be ventilated by mask and then ventilation will continue by LMA until the end of surgery. Pupil size will be measured 4 minute later by the same surgeon. Intervention 2: In intervention group size of the pupil will be measured twice by the surgeon who is unaware of the induction regime. The induction drug in this group is STP 3 g/kg plus atracurium 0.2 mg /kg plus buperonorphinel 0.3 mcg/kg. After induction patient will be ventilated by mask and then ventilation will continue by LMA until the end of surgery. Pupil size will be measured 4 minute later by the same surgeon. Prevention CONDITION: puil size response to opioid. ; ‐‐‐ PRIMARY OUTCOME: Pupil diameter. Timepoint: Before induction anf 5 minutes after induction. Method of measurement: Hand holed papilometer. SECONDARY OUTCOME: Discharge from recovery. Timepoint: At the time of discharge. Method of measurement: questionnaire. Hemodynamic changes. Timepoint: Continuously measured from induction of Anaesthesia till discharge (24 hours). Method of measurement: questionnaire. Shivering. Timepoint: The time at recovery. Method of measurement: observation. INCLUSION CRITERIA: INCLUSION CRITERIA: All patients who are candidates for cataract surgery under general anaesthesia (GA) could be enrolled into this study. Exclusion criteria: Any situation that makes GA difficult or make pupil size measurement difficult (phaco‐emulsification, glaucoma, addiction and history of previous surgery).