The usefulness of cluster-based trend analysis in assessing visual field progression in open-angle glaucoma

Abstract

Purpose : Accurate and timely detection of visual field (VF) progression is essential to proper management of glaucoma. Trend analysis with global indices may not be ideal for the early detection of localized VF defects. Conversely, pointwise trend analysis can be unreliable because of the large variability. Cluster trend analysis is a compromise of these two approaches. We performed a retrospective, observational clinical study to investigate the usefulness of the Octopus (Haag-Streit, Switzerland) EyeSuite®'s cluster trend analysis in assessing progression in glaucoma, compared to the mean of total deviation trend analysis.

Methods : Series of ten reliable visual fields (VFs) with the Humphrey Field Analyzer (Carl Zeiss Meditec) were retrospectively collected from 728 eyes of 475 primary open angle glaucoma patients from eight institutions in Japan. Reliabe VFs were defined as fixation loss rate <20% and also false positive rate <15%. Mean total deviation (mTD) and cluster trend analyses were performed, using all ten VFs (VF1-10) or subsets of VFs, from the first to fifth VF (VF1-5) through to the first to ninth VF (VF1-9). Progression was deemed to have occurred when the progression rate was negative and statistically significant (p value <0.05). Three 'consistency measures' were calculated to compare the performance of detecting progression between cluster and mTD trend analysis: Proportion both progressing (PBP): both of prior series of VFs and VF1-10 were progressive, proportion both not progressing (PBNP): both of prior series of VFs and VF1-10 were not progressive, and proportion inconsistently progressing (PIP): VF1-10 was not progressive but prior series of VFs were progressive.

Results : Cluster and mTD trend analysis results were significantly associated in all clusters and with all VF series. Between 13.4 and 57.0 % of progressive clusters were not-progressive with mTD trend analysis. Up to 4.8% of eyes were progressive with mTD trend analysis, but not-progressive with cluster trend analysis, using the criteria of at least two clusters were progressive. The PBP, PBNP and PIP rates were not significantly different between cluster and mTD trend analysis in most cases.

Conclusions :
Whole field trend analysis can miss local VF progression. Cluster trend analysis seems as robust as mTD trend analysis and useful to assess both sectorial and whole field progression.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.