To compare the ability of Corrected Cluster Trend Analysis (CCTA) and Cluster Trend Analysis (CTA) with event analysis of Octopus visual field series to detect early glaucomatous progression.
One eye of 15 healthy, 19 ocular hypertensive, 20 preperimetric, and 51 perimetric glaucoma (PG) patients were investigated with Octopus normal G2 test at 6-month intervals for 1.5 to 3 years. Progression was defined with significant worsening in any of the 10 Octopus clusters with CCTA, and event analysis criteria, respectively.
With event analysis, 9 PG eyes showed localized progression and 1 diffuse mean defect (MD) worsening. With CCTA, progression was indicated in 1 normal, 1 ocular hypertensive, and 1 preperimetric glaucoma eyes due to vitreous floaters, and 28 PG eyes including all 9 eyes with localized progression with event analysis. The locations of CCTA progression matched those found with event analysis in all 9 cases. In 17 of the remaining 19 eyes, progressing clusters matched the locations that were suspicious but not definitive for progression with event analysis. In the eye with diffuse MD worsening, CTA found significant progression for 7 clusters. For global MD progression rate, eyes worsened with CCTA only did not differ from the stable eyes but had significantly smaller progression rates than the eyes progressed with event analysis (P=0.0002).
In PG, Octopus CCTA and CTA are clinically useful to identify early progression and areas suspicious for early progression. However, in some eyes with no glaucomatous visual field damage, vitreous floaters may cause progression artifacts.