Objective: To assess the effect of supervision on computerized visual field (VF) performance and to determine what patient characteristics predict poor unsupervised performance.
Design: Randomized, crossover, cross-sectional, clinical trial.
Participants: Two hundred unselected patients with definite or suspect glaucoma or neuro-ophthalmic VF indication participated.
Intervention: All patients completed two 30-2 tests of one eye on a Humphrey perimeter, one with continuous active technician supervision and one without supervision after the initial 2 minutes of the test.
Main outcome measures: Visual field reliability and global VF indices were measured.
Results: Supervision had a positive effect on overall reliability (P = 0.04) but not on individual reliability parameters or any of the global VF indices. There was no difference between Humphrey Field Analyzers I and II in the need for supervision. Predictors of need for supervision were low educational level and a prior test result with false-positive responses. Predictors of an unreliable test were advanced age and a prior test with a high proportion of fixation losses.
Conclusion: Supervision is necessary for those with risk factors for unsatisfactory perimetry such as advanced age, low level of formal education, and prior test results with false-positive responses or high fixation losses; in the remainder, omission of supervision can be considered.