Journal of Current Glaucoma Practice

Register      Login

VOLUME 9 , ISSUE 3 ( September-December, 2015 ) > List of Articles

Original Article

Suitability of the Visual Field Index according to Glaucoma Severity

Marina CC Sousa, Luis G Biteli, Jessica S Maslin, Mauro T Leite, Tiago S Prata

Keywords : Functional correlation, Functional evaluation, Glaucoma blindness, Stages of glaucoma, Visual field index

Citation Information : Sousa MC, Biteli LG, Maslin JS, Leite MT, Prata TS. Suitability of the Visual Field Index according to Glaucoma Severity. J Curr Glaucoma Pract 2015; 9 (3):65-68.

DOI: 10.5005/jp-journals-10008-1186

License: CC BY-NC 4.0

Published Online: 01-08-2019

Copyright Statement:  Copyright © 2015; The Author(s).


Purpose: To investigate the suitability of the visual field index (VFI) in different degrees of disease severity in glaucoma patients. Methods: In this cross-sectional study, we consecutively enrolled patients with primary open-angle glaucoma and glaucoma suspects (ocular hypertension). All eyes required a reliable standard automated perimetry (SAP) test to be included. Subjects were categorized into five groups based on glaucoma severity using SAP's mean deviation (MD). To evaluate the correlation among VFI, MD and pattern standard deviation (PSD), a linear regression model was built. To evaluate the nature of the correlation (i.e. linear vs nonlinear), results were plotted in a scatterplot graph. Results: One hundred and twenty-two eyes of 81 patients (mean age, 59.8 ± 14.5 years) were included. A strong, positive association was found between MD and VFI values (R2 = 0.98, p < 0.001), showing a 3.2% reduction in the VFI for each dB loss in the MD index. It was noticed that 15% of eyes with mild glaucoma (average MD of -3.1 dB) had VFI > 99%. Considering only the eyes with mild and moderate damage in the regression, we found a weaker (nonlinear) correlation than the one we found using all eyes (R2 = 0.85, p < 0.001). There was also a significant, nonlinear correlation between VFI and PSD (R2 = 0.85, p < 0.001). Although higher PSD values were found with increasing visual field damage, this initial trend was reversed when VFI became smaller than 50%, approximately. Conclusion: Visual field index had a strong correlation with MD; however, this correlation was weaker in mild disease, as some patients with early disease had very high VFI values (ceiling effect). Therefore, initial deterioration in visual field status (as assessed by MD values) in patients with early disease may not be detectable using the VFI alone.

PDF Share
  1. Advanced Glaucoma Intervention Study. 2. Visual field test scoring and reliability. Ophthalmology 1994 Aug;101(8): 1445-1455.
  2. Gardiner SK, Demirel S, Johnson CA. Perimetric indices as predictors of future glaucomatous functional change. Optom Vis Sci 2011 Jan;88(1):56-62.
  3. Bengtsson B, Heijl A. A visual field index for calculation of glaucoma rate of progression. Am J Ophthalmol 2008 Feb;145(2):343-353.
  4. Rao HL, Kumar AU, Babu JG, Senthil S, Garudadri CS. Relationship between severity of visual field loss at presentation and rate of visual field progression in glaucoma. Ophthalmology 2011 Feb;118(2):249-253.
  5. Rao HL, Jonnadula GB, Addepalli UK, Senthil S, Garudadri CS. Effect of cataract extraction on visual field index in glaucoma. J Glaucoma 2013 Feb;22(2):164-168.
  6. Artes PH, O'Leary N, Hutchison DM, Heckler L, Sharpe GP, Nicolela MT, Chauhan BC. Properties of the statpac visual field index. Invest Ophthalmol Vis Sci 2011 Jun;52(7): 4030-4038.
  7. Giraud JM, Fenolland JR, May F, Hammam O, Sadat AM, Boumezrag AB, Renard JP. Analysis of a new visual field index, the VFI, in Ocular Hypertension and Glaucoma. J Fr Ophthalmol 2010 Jan;33(1):2-9. (Fren).
  8. Dorairaj S, Barkana Y, Nasser C. The visual field index (VFI): correlation with mean deviation (MD) and visual disability parameters in advanced glaucoma. IOVS 2014:ARVO E-abstract 4301-B0069.
  9. Casas-Llera P, Rebolleda G, Munoz-Negrete FJ, Arnalich- Montiel F, Perez-Lopez M, Fernandez-Buenaga R. Visual field index rate and event-based glaucoma progression analysis: comparison in a glaucoma population. Br J Ophthalmol 2009;93(12):1576-1579.
  10. Ang GS, Mustafa MS, Scott N, Diaz-Aleman VT, Azuara- Blanco A. Perimetric progression in open angle glaucoma and the visual field index (VFI). J Glaucoma 2011 Apr- May;20(4):223-227.
  11. Heijl A, Buchholz P, Norrgren G, Bengtsson B. Rates of visual field progression in clinical glaucoma care. Acta Ophthalmol 2013 Aug;91(5):406-412.
PDF Share
PDF Share

© Jaypee Brothers Medical Publishers (P) LTD.