Effect of Cognitive Demand on Functional Visual Field Performance in Senior Drivers with Glaucoma.

Viswa Gangeddula,Maud Ranchet,Abiodun E Akinwuntan,Kathryn Bollinger,Hannes Devos

doi:10.3389/fnagi.2017.00286

Abstract

Purpose: To investigate the effect of cognitive demand on functional visual field performance in drivers with glaucoma.Method: This study included 20 drivers with open-angle glaucoma and 13 age- and sex-matched controls. Visual field performance was evaluated under different degrees of cognitive demand: a static visual field condition (C1), dynamic visual field condition (C2), and dynamic visual field condition with active driving (C3) using an interactive, desktop driving simulator. The number of correct responses (accuracy) and response times on the visual field task were compared between groups and between conditions using Kruskal–Wallis tests. General linear models were employed to compare cognitive workload, recorded in real-time through pupillometry, between groups and conditions.Results: Adding cognitive demand (C2 and C3) to the static visual field test (C1) adversely affected accuracy and response times, in both groups (p < 0.05). However, drivers with glaucoma performed worse than did control drivers when the static condition changed to a dynamic condition [C2 vs. C1 accuracy; glaucoma: median difference (Q1–Q3) 3 (2–6.50) vs. controls: 2 (0.50–2.50); p = 0.05] and to a dynamic condition with active driving [C3 vs. C1 accuracy; glaucoma: 2 (2–6) vs. controls: 1 (0.50–2); p = 0.02]. Overall, drivers with glaucoma exhibited greater cognitive workload than controls (p = 0.02).Conclusion: Cognitive demand disproportionately affects functional visual field performance in drivers with glaucoma. Our results may inform the development of a performance-based visual field test for drivers with glaucoma.

Highlights

Glaucoma is a progressive optic neuropathy characterized by slow degeneration of retinal ganglion cells and their axons resulting in irreversible loss of peripheral field of vision (Weinreb and Khaw, 2004; Weinreb et al, 2014)
Both groups differed significantly in TMT B, mean deviation and pattern standard deviation of left eye and mean deviation of right eye derived from Humphrey visual field analyzer (HVF)
Within group comparisons showed a significant effect of cognitive demand on functional visual field performance in both groups (Table 2)

Summary

Introduction

Glaucoma is a progressive optic neuropathy characterized by slow degeneration of retinal ganglion cells and their axons resulting in irreversible loss of peripheral field of vision (Weinreb and Khaw, 2004; Weinreb et al, 2014). Outcomes on the HFV test are only moderately predictive of driving safety outcomes in glaucoma (Ball et al, 1993; Tatham et al, 2015), which may be attributed to the fact that safe driving requires intact physiological visual field, and depends on the attentional capacity of the driver and the cognitive demand of the task (Owsley et al, 1998; Rubin et al, 2007; Owsley and McGwin, 2010). These three factors define the individual’s functional visual field

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