No abstract

We tested 10 healthy subjects on the Humphrey Field Analyzer using Goldmann stimulus sizes I-V to determine the effect of varying the area of the stimulus upon threshold fluctuation. Our results show similar components of fluctuation for the size III stimulus as in past studies. However, an increased total fluctuation was observed for Goldmann stimulus sizes I (3.69 decibels) and II (3.17 decibels) and a similar fluctuation for stimulus sizes IV (2.64 decibels) and V (2.51 decibels) as compared to stimulus size III (2.52 decibels). The study suggests no advantage results in reduced threshold fluctuation by changing the Goldmann stimulus from a size III when testing normal individuals on the Humphrey Field Analyzer.

No abstract

We studied 207 glaucoma patients (207 eyes) who had two successive visual tests on the Humphrey Field Analyzer to determine the association of unreliability (> 10% incidence of a missed catch trial test) with threshold variation. We found that in patients where one visual field showed > 30% false negative or positive errors, and the other visual field also was unreliable, a significant increase in the variance of the mean defect existed from reliable patients (p < 0.05). Of patients who had only one of two visual fields which was unreliable (from false negative errors), only those with marked glaucomatous visual field loss (< -15 dB depth of defect) showed a greater variance in mean defect between examinations over reliable patients (p < 0.05). In total, 41 patients (19.8%) had unreliable visual fields associated with statistically increased threshold variation. This study suggests that patient reliability should be considered when interpreting changes in threshold between automated visual field examinations.