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 Analyz er (HFA) I to the same lest procedure in the new Humphrey Field Analyz er 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 visua l field loss were tested with the two instruments plus a retest on a s eparate HFA I. All participants had undergone at least one prior visua l field examination. To minimize the influence of any residual learnin g or fatigue effects, the order of testing for the three visual field examinations was counterbalanced across subjects. A total of 250 patie nts were tested (81 patients with ocular hypertension, 81 patients wit h early glaucomatous visual field loss, and 88 patients with more adva nced glaucomatous visual field loss), Results: No statistically signif icant differences were observed between thresholds, visual field indic es, 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, Thes e results were consistent across the range of visual field characteris tics shown by the ocular hypertensive, early glaucoma, and moderate gl aucoma patient groups. Conclusions: The authors' results indicate that there are no differences in the visual field results obtained with th e HFA I and the HFA [I. These findings suggest that with careful atten tion to test protocols, the HFA I and HFA II may be used interchangeab ly to observe patients, even within the context of multicenter clinica l trials.