Baseline Age and Mean Deviation Affect the Rate of Glaucomatous Vision Loss

Purpose: The purpose of this study was to assess the relationship between the rate of the glaucomatous visual field (VF) worsening and baseline age and baseline VF mean deviation (MD). Design: This study was a retrospective, multisite cohort. Participants: A total of 84,711 reliable Swedish Interactive Thresholding Algorithm 24-2 VF tests from 8167 eyes from 5644 patients with >= 6 VF tests, >= 5 years of follow-up, baseline age 18 years or above and baseline MD >=-10 dB, and at least 2 abnormal VF tests were included from the Glaucoma Research Network Database. Methods: The global mean deviation rates (MDRs) and pointwise total deviation rates (TDRs) of VF progression (dB/y) were calculated for each eye using linear regression. The relationships between MDR and baseline age and MD were determined using linear mixed-effects models and logistic regression, with rapid progression defined as an MDR <=-1.0 dB/y. The relationships between TDR and baseline age and baseline MD were determined using linear mixed-effects models. Main Outcome Measures: Coefficients of the regression models. Results: In individual mixed-effects models both baseline age (beta=-0.0079 dB/y(2); P<0.001) and baseline MD (beta=0.012/y; P<0.001) were associated with faster progression. All parameters were statistically significant in the full model with both parameters and their interaction (beta=0.00065; P=0.0017) as covariates. With logistic regression, each year increase in baseline age increased the odds of belonging to the rapid-progressing group by a factor of 1.033, and each unit increase in baseline MD (less severe visual loss) decreased the odds by a factor of 0.8821. The mean pointwise TDR ranged from -0.21 to -0.55 dB/y, with the most rapid pointwise progression observed in the nasal and paracentral regions of the field. Conclusions: Older age and worse MD at baseline are associated with more rapid VF progression in this large dataset. The effect of age on MDR is influenced by baseline MD severity, supporting the importance of early detection and more aggressive therapy in older patients with worse VF damage. The pointwise rate of VF loss varies across the VF, providing a means for physicians to more effectively monitor progression.