Intra-ocular pressure changes in patients with glaucoma. Comparison between the laryngeal mask airway and tracheal tube.

We performed a randomised prospective study in 20 patients with glaucoma to examine the effects of tracheal intubation and laryngeal mask insertion on intra-ocular pressure, mean arterial blood pressure and heart rate. After induction of anaesthesia with propofol, intra-ocular pressure decreased significantly below baseline values in both the laryngeal mask and tracheal tube groups. After insertion of the laryngeal mask, intra-ocular pressure remained significantly below baseline values in all patients. In contrast, tracheal intubation was associated with a significant increase in intra-ocular pressure to above baseline values in three out of eight patients. Insertion of the laryngeal mask had minimal effects on mean arterial blood pressure and heart rate, whereas tracheal intubation significantly increased both factors relative to pre-intubation values.