R E Van Coevorden | PubMed Health

PubMed1999

Continuous visual field test supervision may not always be necessary.

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.

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PubMed1997

A multicenter comparison study of the Humphrey Field Analyzer I and the Humphrey Field Analyzer II.

PURPOSE: The purpose of the study is to determine the comparability of the 30-2 full-threshold program in the original Humphrey Field Analyzer (HFA) I to the same test procedure in the new Humphrey Field Analyzer II. METHODS: At each of five clinical centers, one eye of patients with ocular hypertension and normal visual fields, patients with early glaucomatous visual field loss, and patients with more advanced visual field loss were tested with the two instruments plus a retest on a separate HFA I. All participants had undergone at least one prior visual field examination. To minimize the influence of any residual learning or fatigue effects, the order of testing for the three visual field examinations was counterbalanced across subjects. A total of 250 patients were tested (81 patients with ocular hypertension, 81 patients with early glaucomatous visual field loss, and 88 patients with more advanced glaucomatous visual field loss). RESULTS: No statistically significant differences were observed between thresholds, visual field indices, or reliability indices obtained with the HFA I and the HFA II. The small differences between the two instruments were equivalent to the variation observed for test-retest measures using only the HFA I. These results were consistent across the range of visual field characteristics shown by the ocular hypertensive, early glaucoma, and moderate glaucoma patient groups. CONCLUSIONS: The authors' results indicate that there are no differences in the visual field results obtained with the HFA I and the HFA II. These findings suggest that with careful attention to test protocols, the HFA I and HFA II may be used interchangeably to observe patients, even within the context of multicenter clinical trials.

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