Comparison of Humphrey versus Compass Perimetry for Hemianopsia

Up to 57% of stroke patients experience visual defects. Visual restitution therapy post-stroke remains controversial, with some attributing improvements to adaptive eye scanning movements rather than true field augmentation. We compare Compass fundus-tracking perimetry (CMP), which compensates for eye movements, to the Humphrey Field Analyzer (HFA) for homonymous hemianopsia. Nine patients (mean age: 47) with homonymous hemianopsia on HFA and corresponding neuroimaging defect were prospectively tested on the same day using the HFA (24-2 SITA Fast) and CMP (24-2 ZEST fast). Reliability indices, mean deviation (MD), and visual field index (VFI for HFA; FDPI for Compass) were compared via median differences and the Wilcoxon signed-rank test. The CMP had a significantly lower MD (median difference: -0.33 dB, p = .02), significantly greater false negative rate (median difference: 27%, p = .04), and a significantly longer test duration (median difference: 87 seconds, p = .01) than HFA. However, no between-analyzer difference occurred for visual field index (median difference: 6.8%, p = .65), false positive rate (median difference: -2.8%, p = .18), CMP blind spot index and HFA fixation losses (median difference: 0, p = .79). Bland-Altman plots showed acceptable agreement, with a + 2.42 dB bias in MD favoring CMP. CMP offers real-time compensation for fixation losses but did not show a clinically significant advantage over HFA for homonymous hemianopsia.