Psychological Stress and Intraocular Pressure in Glaucoma: A Randomized Controlled Trial

Abstract

To evaluate the intraocular pressure (IOP) behavior after applying a standardized protocol to induce psychological stress in primary open-angle glaucoma (POAG) patients. Randomized controlled trial. A total of 39 POAG patients were included: 18 in the stress group and 21 in the control group. Patients were randomized to undergo the Trier Social Stress Test (TSST) or to be included in the control group. All participants were submitted to a modified diurnal tension curve (DTC) 1 to 4 weeks before randomization, with 3 IOP measurements performed between 8:00 AM and 2:00 PM. We evaluated the response to the TSST by measuring the levels of salivary cortisol, salivary amylase, IOP, mean arterial pressure and heart rate before, immediately after, and 40 minutes after the TSST. The State Trait Anxiety Inventory (STAI) was applied to evaluate the levels of anxiety at the same time intervals. Changes in IOP (mmHg), salivary cortisol and amylase, heart rate, mean arterial pressure and STAI scores. At baseline, there were no significant differences between the groups regarding age (P=0.661), gender (P=0.669), salivary cortisol (P=0.104) and mean DTC IOP for the right (P=0.439) and left (P=0.576) eyes. We observed a significant mean IOP increase of 3.8 mmHg (right eye, P<0.001) and 4.1mmHg (left eye, P<0.001) when we compared IOP measurements obtained during the DTC and immediately after TSST. Salivary cortisol (5.9 nmol/L, P=0.004), salivary amylase (323,388 UL, P=0.004), mean arterial pressure (10.1mmHg, P<0.001) and heart rate (12.9bpm, P<0.001) also increased significantly after the TSST. In addition, 61.1% (11 out of 18) of the patients in the TSST group showed an IOP increase greater than 4 mmHg following the test. The STAI-state score significantly increased after the TSST compared to baseline (P<0.001) and decreased from post-stress to the recovery period (P<0.001). POAG patients present significant elevations of IOP, salivary cortisol and amylase, mean arterial pressure, heart rate and STAI scores after psychological stress induced by the TSST.