NOV 04, 2014
This prospective study found that visual field testing does not induce an increase in IOP in the majority of patients with open-angle glaucoma (OAG). However, a small percentage showed an increase greater than 2 mm Hg.
The authors used noncontact tonometry to measure IOP before and immediately after visual field testing of both eyes in 106 OAG patients.
The average IOP in the right eye decreased significantly to 12.3 ± 2.6 mm Hg, whereas IOP in the left eye was not changed significantly. An elevation of ≥ 2 mm Hg after visual field testing occurred in 2.8 % of right eyes and 0.9 % of left eyes.
Refractive error was not significantly changed after visual field testing. Multivariate analysis showed statistically significant correlations between the IOP decrease after visual field testing and baseline IOP and central corneal thickness.
They note that there seems to be a discrepancy between the findings based on accommodative-induced and visual field testing-induced IOP changes. It is possible that when performing visual field testing, other factors, including psychological stress rather than purely sustained accommodation and aging, might be involved in the IOP alterations.
They conclude that since visual field testing is an essential examination for glaucoma management, special care should be taken to interpret IOP values taken after visual field testing especially in eyes with OAG.