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Abstract

Objective: To compare the effects of spontaneous versus controlled ventilation on IntraocularPressure (IOP) with concomitant haemodynamic changes during cataract extraction and intraocular (IOL) implantsurgery under anaesthesia. Design: Comparative study. Place and Duration of Study: The study was conducted atdepartment of Anesthesiology Combined Military Hospital Jhelum Cantt from Jan 2005 to Oct 2005. Subjects andMethods: 40 ASA I and II patients of both sexes aged 40-68 years, undergoing surgical cataract extraction werestudies. In 20 patients ventilation was controlled while the other 20 patients breathed spontaneously during surgery.IOP was measured preoperatively in non-operated eye.Results: Intraocular pressure (IOP) decreased below the baseline after induction of anaesthesia but it markedly increased after intubation in both group. During operation IOPdecreased more in controlled ventilation group than spontaneous ventilation group. At the end of surgery beforeextubation, IOP increased in both groups with a greater rise in spontaneous ventilation group and extubation wasfollowed by a further rise in IOP in both groups. Heart rate (HR) and arterial blood pressure (BP) changes followedalmost the same pattern as IOP. Conclusion: General anaesthetics decrease IOP in general. Laryngoscopy andintubation are anaesthesia-related events, which cause rise in IOP. In appropriate patients, general anaesthesia withcontrolled ventilation is an acceptable technique for intraocular surgery offering advantages in terms of intraocularpressure and cardiovascular stability compared to spontaneous ventilation.