Abstract
Purpose: :
Visual field index (VFI) is a new global parameter of Humphrey field analyzer based on pattern deviation plot, with value ranging from 0% to 100%. The purpose of this study was to investigate the prevalence and agreement of visual field (VF) progression determined by Modified Anderson criteria, linear regression of mean deviation (MD), and VFI in open angle glaucoma (OAG) patients, whose intraocular pressure (IOP) was well controlled over a longitudinal follow-up period.
Methods: :
Two-hundred and fifty-one eyes of 168 OAG patients with a minimum of five reliable VFs and a follow-up period of at least 4 years (mean follow-up, 73.8±22.2months) were included. Statistically significant (P<0.05) negative slope of MD and VFI by linear regression method was regarded as progression. Kappa statistics were used to estimate the agreement between the different approaches to assess VF progression.
Results: :
Overall, 20.7, 8.8 and 13.1% of OAG eyes progressed by Modified Anderson criteria, MD and VFI linear regression analysis. Agreements between VFI and modified Anderson criteria, VFI and MD linear regression analysis were 0.537, 0.533, respectively. Agreement between modified Anderson criteria and MD linear regression analysis was 0.384. Mean progression rate of MD and VFI were -0.199±0.527 dB/year and 0.738±1.53%/year.
Conclusions: :
Considerable portion of OAG patients progressed by three VF criteria despite well controlled IOP. Outcome of VFI linear regression analysis showed fair agreement with MD linear regression analysis and modified Anderson criteria. VFI linear regression analysis showed higher rate of progression detection than did MD linear regression analysis. VFI can be a useful method for estimation of glaucoma progression detection.
Keywords: visual fields • imaging/image analysis: clinical • image processing