[Intraocular pressure values in intubation anesthesia in patients with and without chronic open angle glaucoma]

A number of clinical studies have investigated the influence of hypnotics and relaxants on intraocular pressure. All of them referred to the normal eye. Our goal was to show if there is a difference in intraocular pressure profile during general anesthesia between eyes with and without primary open angle glaucoma.

We prospectively examined two groups of 20 patients with and without primary open angle glaucoma. Intraocular pressure (IOP) readings were taken using a Perkins hand held applanation tonometer during routine surgery on cataract or glaucoma on the fellow eye. Balanced anesthesia was carried out using Etomidate, Vecuronium, Fentanyl, N2O and Enflurane.

In the glaucoma group IOP fell from 20.3 +/- 4.1 mm Hg before induction of anesthesia (baseline) to 13.2 +/- 3.8 mm Hg (65% of baseline) after induction and 12.6 +/- 4.2 mm Hg (62%) 5 minutes after induction. In the non-glaucoma group IOP was 16.3 +/- 3.5, 9.7 +/- 3.0 (62%) und 9.6 +/- 3.0 (59%) respectively. Directly after placement of endotracheal tube we read 17.8 +/- 7.6 mm Hg (87%) in the glaucoma and 13.0 +/- 5.9 mm Hg (82%) in the non-glaucoma group. Shortly before removal of endotracheal tube we found IOP to be 21.3 +/- 4.5 mm Hg (107%) in the glaucoma and 17.8 +/- 6.8 mm Hg (106%) in the non-glaucoma group. Back on the ward we measured 19.8 +/- 4.1 mm Hg (94%) and 15.4 +/- 3.5 (93%) respectively. Pressure changes relative to baseline values show no statistically significant differences between the two groups.

General anesthesia lowers IOP to the advantage of intraocular surgery. There is no statistically significant difference in pressure change relative to baseline value in eyes with and without primary open angle glaucoma.