Guided Progression Analysis (GPA)
Humphrey Field Analyzer II-
i
series User Manual 2660021145640 A
8-16
Figure 8.6b Progressing Right Eye – Follow Up
On this Follow-up page of a Full GPA report, numerous points are flagged with progression triangles
across the three Progression Analysis plots F. GPA Alerts for “Possible Progression” and “Likely
Progression” appear, indicating at least three points show deterioration over the second and third
consecutive tests.
One advantage of using GPA is that it can demonstr
ate change in points that have already been
flagged at the highest probability level relative to normal (black squares, E). In the same area on the
Progression Analysis plots F, the GPA progression indicator triangles identify the changing points.
Previously, doctors would resort to looking at the pattern deviation numbers and make comparisons
of previous values to attempt to discover change in the 0.5% points. Now, the GPA calls out these
progressing points and applies its statistical knowledge of expected inter-test variability to highlight
points with statistically significant change.