Influence of mental stress on intraocular pressure and visual field testing: is there a white coat syndrome in glaucoma?

Purpose: To investigate the effects of mental stress stimulus on intraocular pressure (IOP) measurement and visual field (VF) testing. Methods: Patients with open angle glaucoma underwent a baseline IOP measurement and VF testing. Afterwards, they completed a computerized mental stress test (Stroop test) which is a known standardized method to induce mental stress. After test completion, patients underwent a second IOP measurement and VF testing. Results: Seventy-two eyes of 36 patients were enrolled. Mean age was 67.0 ± 9.5 years (range 47–84 years). The mean baseline IOP was 15.0 mmHg, and after the Stroop mental stress test, IOP increased to 16.0 mm Hg (P < 0.001). There was a trend towards significant mean deviation decreased from -6.9 dB to -8.0 dB (P = 0.054, t-test) following the stress test. This difference became significant using the Wilcoxon nonparametric test (P = 0.008). Correlation was found between glaucoma severity and change in IOP (P = 0.02) and PSD (P < 0.01). Conclusions: We found a small but statistically significant increase in IOP and a trend towards deterioration of visual field mean deviation, following a short mental stress test. Patients with more severe glaucoma showed more pronounced changes. Our results suggest that mental stress could affect IOP measurement in the clinic.[Figure not available: see fulltext.].