Progression detection in different stages of glaucoma: mean deviation versus visual field index

Abstract

We evaluated and compared visual field index (VFI) and mean deviation (MD) capacity in detecting glaucoma progression at different stages. Participants were classified as having early-, moderate-, or advanced-stage glaucoma. Trend-based approaches (TA) using linear regression analysis of the VFI and MD (VFI TA, MD TA) over patient age were performed. The rate was determined by both approaches at different stages of glaucoma. We analyzed 173 eyes of 173 participants (mean follow-up 6.2 years). Glaucoma progressed in 24 eyes (13.9%) as determined by VFI TA and in 21 eyes (12.1%) as determined by MD TA. Agreement between VFI TA and MD TA was moderate to good (κ = 0.617). The rate was -0.29 ± 2.31 dB per year as determined by MD TA and 1.25 ± 4.79% per year as determined by VFI TA. Progression rate according to glaucoma severity was not significantly different among subgroups when assessed by both trend-based approaches. VFI TA and MD TA performed similarly in measuring different stages of glaucoma progression. However, VFI TA and MD TA did not have agree perfectly in glaucoma progression detection. As glaucomatous changes can be general or localized, we suggest that changes in the MD and VFI should be considered when monitoring glaucoma progression through all stages.