Elevation of intraocular pressure in glaucoma patients after automated visual field testing

Abstract

Purpose: To examine whether automated visual field (VF) testing may exert a short-term influence on subsequent intraocular pressure (IOP) measurement during the same visit.

Methods: We reviewed patients with primary open-angle glaucoma whose most recent visit occurred at a major academic institution from July to December 2009 and who had 3 visits without intervening changes in glaucoma management within the previous 5 years. Exclusion criteria were patient admittance of nonadherence with medical therapy and documented difficulty of IOP measurement. One hundred nine right eyes from 109 patients were included. IOP obtained within 30 minutes after VF testing was compared with IOP from the previous and next visits without VF testing. Subgroup analyses included the role of reliability of VF test performance, surgical versus medical IOP control, and different topical medications.

Results: The average IOP measured after VF testing was 14.9 ± 4.7 mm Hg, higher than both the previous (13.7 ± 4.4 mm Hg, P < 0.001) and next visits without VF examination (13.8 ± 4.4 mm Hg, P < 0.001). A total of 22.9% of patients experienced a more than 20% increase of IOP. Eyes with surgical control had less IOP elevation than eyes with medical control (3.1% ± 15.9% vs. 11.7% ± 17.4%, P = 0.009). Users of β-blockers or α-2-agonists had less IOP elevation than eyes controlled with prostaglandins or carbonic anhydrase inhibitors (0.9% ± 15.1% vs. 9.0% ± 12.3%, P = 0.030).

Conclusions: This retrospective study suggests that patients with primary open-angle glaucoma experience a small and transient increase in IOP after VF testing and that this effect may be lower after surgical pressure control.

FIGURE 1

Cumulative distribution of time-of-day difference between intraocular pressure (IOP) measurements on visual field (VF) testing days compared with non-VF testing days. Cumulative percentages shown. Time-of-day difference was calculated as time of IOP measurement on VF testing day minus the average time of IOP measurement on non-VF testing days.

FIGURE 2

Intraocular pressure (IOP) during 3 consecutive visits with standard error of the mean (SEM). Square points represent average IOP for each visit; error bars indicate SEM for each visit. IOP measured during the second visit (with visual field testing) was higher than both the first and third visits. IOP measured during the first and third visits were not different.

FIGURE 3

Distribution of intraocular pressure (IOP) change after visual field (VF) testing. VF testing-associated IOP change was expressed as a percent change in IOP measured during the VF visit compared with the baseline average IOP measured during the previous and next visits. The mean IOP change was 10.6% ± 20.1%; 22.9% of all patients experienced >20% increase, 8.3% of all patients experienced >30% increase.