Comparison of Visual Field Index and Event Based Glaucoma Progression Analysis

Abstract

Purpose: : To compare event-based analysis GPA I versus the new GPA II software, including pattern deviation based trend analysis (VFI) to detect progression in a glaucoma population.

Methods: : A retrospective study conducted in 90 eyes of 90 patients that had a minimum of five visual fields and a follow-up period of at least two years.

Results: : GPA detected progression in 17.77 % of the eyes that showed no progression using VFI. GPA detected progression 6.75 months earlier than did VFI. GPA I and II showed a similar progression rates (31.11 and 28.88%). There was an excellent agreement between GPA I and II (k=0.94).There was a moderated agreement between the VFI versus MD linear analysis (k=0.52) and GPA criteria (k=0.50). Mean rate of progression of MD and VFI was -0.41 dB and -1.30 % per year with a correlation: rho= 0.824 (p<0.01). Mean of number of visual fields was 7.33 and 6.01 in VFI progressing and no progressing patients (p=0.023). Mean of follow up time was 6.12 and 4.89 years in VFI progressing and no progressing patients (p=0.004).

Conclusions: : Event based analysis software GPA I and II had a high level of agreement. GPA showed earlier and more sensitive to detect progression than VFI rate and both had an only moderate agreement. VFI is likely to detect progression in patients with a greater number of visual field and a larger follow-up. VFI rate of progression seems to be better than MD linear regression analysis to know patient’s velocity progression.

Keywords: visual fields • optic nerve • optic disc