HOW OFTEN DO PATIENTS NEED VISUAL-FIELD TESTS

Background: This study was undertaken to determine whether the interva l between visual field tests affects the ability to detect progressive glaucomatous field loss. Methods: One hundred and nineteen retinal lo cations which were deteriorating significantly by greater than or equa l to 1 dB/year (untreated normal tension glaucoma patients: 6 eyes) we re studied. Analysis was repeated using 'thinned' visual field tests: one test per year instead of the complete three per year over a period of 4 years. Results: The 'thinned' tests identified only 45.4% of the deteriorating points over the 4-year period. Furthermore, there was a mean delay of 1.10 years in detection (P < 0.01). Conclusions: Less f requent visual field testing detects fewer progressing locations and d etects them later.