Comparison of the Automated Pattern-Noise (PANO) Glaucoma Test with the HFA, an FDT Stimulus, and the Fundus Area Cup-to-disk Ratio.

AIM AND OBJECTIVE

To compare the results of a new automated glaucoma test-Pattern-Noise (PANO)-to the Humphrey Visual Field Analyzer-II (HFA), the fundus area cup-to-disk ratio (CDR), and a frequency doubling technology (FDT) stimulus.

MATERIALS AND METHODS

This was a prospective study performed in the West-Region of Cameroon. Two hundred and nineteen eyes of 122 adult patients were included with a clinical suspicion of normal-tension or primary open-angle glaucoma and no other major ocular pathology. Eyes were examined with PANO, HFA (24-2 SITA standard), and FDT-stimulus in a randomized order followed by clinical assessment of the CDR.

RESULTS

Parametric correlation of the mean contrast threshold of PANO with the mean contrast threshold of FDT-stimulus, total deviation of HFA, and area CDR was 0.94, -0.85, and 0.62, respectively ( < 0.001 for all values). Spatial distribution of sensitivity thresholds is highly correlated ( < 0.001) at all points in the visual field between PANO and HFA. With cut-off values of 3 ± 1 dB for HFA mean deviation and 4 ± 1 for PANO mean contrast threshold and after eliminating borderline cases, PANO's sensitivity was 95% and specificity 60%. The mean patient age was 45.2 ± 15.8 years. Mean thresholds of PANO and FDT-stimulus decreased with increasing age. Mean examination time was 7.1 ± 1.8 minutes for PANO, 5.9 ± 1.3 minutes for HFA, and 4.7 ± 1.3 minutes for FDT-stimulus. The mean percentage of false-positives per examination was 4.95% for PANO, 4.62% ( = 0.025) for FDT-stimulus, and 2.10% for HFA.

CONCLUSION

The results showed that PANO was successful in suspecting the presence of glaucoma. Pattern-Noise examination led to findings that were significantly correlated to HFA, FDT stimulus, and area CDR. Some patterns of defect were also correlated. Furthermore, PANO showed a reasonable examination time and error rate.

CLINICAL SIGNIFICANCE

Affordable and robust visual field devices are lacking in large parts of the developing world. Comparing them to established methods is a prerequisite to their clinical use.

HOW TO CITE THIS ARTICLE

Hannen T, El-Khoury S, Patel R, Comparison of the Automated Pattern-Noise (PANO) Glaucoma Test with the HFA, an FDT Stimulus, and the Fundus Area Cup-to-disk Ratio. J Curr Glaucoma Pract 2021;15(3):132-138.