Influence of automated visual field testing on intraocular pressure

Background To evaluate the influence of automated visual field (VF) testing on intraocular pressure (IOP) in patients with ocular hypertension (OHT) or glaucoma. Methods We conducted a prospective observational study in the glaucoma department at Quinze-Vingts National Ophthalmology Hospital in Paris. Ninety-five right eyes of 95 patients followed for glaucoma or OHT were included. IOP was measured three times using a Nidek NT-510 non-contact tonometer within a maximum of 5 min before and after VF testing. Sub analyses using logistic regression analysis were performed to evaluate the impact of gender, age, central corneal thickness (CCT), mean deviation (MD) of the VF, VF test duration and filtration surgery on IOP fluctuations. Results There was no significant change in IOP after VF testing, with IOP's 15.14 +/- 4.00 mmHg before and 14.98 +/- 3.33 mmHg after the VF (P = 0.4). The average change in IOP was 0.15 +/- 1.82 mmHg. Using multivariate analysis, no effect of the VF test on IOP was found (global model fit R-2 = 0.12), whether based on duration of the VF test (P = 0.18) or the MD (P = 0.7) after adjustment for age, gender, CCT and history of glaucoma surgery. Similarly, there was no significant difference within different types of glaucoma, including open-angle glaucoma(P = 0.36),chronic angle closure glaucoma (P = 0.85) and OHT (P = 0.42). The subgroup of patients with an IOP elevation >= 2 mmHg had a significantly higher VF test duration (P = 0.002). Conclusion VF testing does not influence IOP as measured with a non-contact tonometer.