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Driving with binocular visual field loss? A study on a supervised on-road parcours with simultaneous eye and head tracking.

Kasneci E, Sippel K, Aehling K, Heister M, Rosenstiel W, Schiefer U, Papageorgiou E - PLoS ONE (2014)

Bottom Line: In addition, patients who passed the test performed more glances towards the area of their visual field defect.In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning.Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario.

View Article: PubMed Central - PubMed

Affiliation: Computer Engineering Department, Wilhelm-Schickard-Institute of Computer Science, University of Tübingen, Tübingen, Germany.

ABSTRACT
Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the central area of the visual field than patients who failed the test. In addition, patients who passed the test performed more glances towards the area of their visual field defect. In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning. Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario.

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Related in: MedlinePlus

The proportion of glances in percent (PGP) of glaucoma patients towards the VFD during the on-road assessment (Table 2). Else, see Figure 6.
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pone-0087470-g007: The proportion of glances in percent (PGP) of glaucoma patients towards the VFD during the on-road assessment (Table 2). Else, see Figure 6.

Mentions: Figure 6 and Figure 7 present the proportion of gazes in percent (PGP) towards the visual field defect for HVFDs (HP) and glaucoma patients (GP), respectively. For HVFDs patients, the PGP towards the VFD is independent of the binocular VFD size (Pearson correlation HP: r = 0.5312, p = 0.1412, Figure 6). This is also applicable for the HL and HR subgroups (Pearson correlation HL: r = 0.6320, p = 0.2526; Pearson correlation HR: r = 0.8019, p = 0.1981). However, for glaucoma patients there was a significant correlation between the size of the VFD and the PGP towards it (Pearson correlation GP: r = 0.9611, p<0.001). Both Figures show that the size of the VFD cannot predict the driving performance of patients. However, due to the small number of participants in each subgroup, these results should be treated with caution and need further investigation.


Driving with binocular visual field loss? A study on a supervised on-road parcours with simultaneous eye and head tracking.

Kasneci E, Sippel K, Aehling K, Heister M, Rosenstiel W, Schiefer U, Papageorgiou E - PLoS ONE (2014)

The proportion of glances in percent (PGP) of glaucoma patients towards the VFD during the on-road assessment (Table 2). Else, see Figure 6.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921141&req=5

pone-0087470-g007: The proportion of glances in percent (PGP) of glaucoma patients towards the VFD during the on-road assessment (Table 2). Else, see Figure 6.
Mentions: Figure 6 and Figure 7 present the proportion of gazes in percent (PGP) towards the visual field defect for HVFDs (HP) and glaucoma patients (GP), respectively. For HVFDs patients, the PGP towards the VFD is independent of the binocular VFD size (Pearson correlation HP: r = 0.5312, p = 0.1412, Figure 6). This is also applicable for the HL and HR subgroups (Pearson correlation HL: r = 0.6320, p = 0.2526; Pearson correlation HR: r = 0.8019, p = 0.1981). However, for glaucoma patients there was a significant correlation between the size of the VFD and the PGP towards it (Pearson correlation GP: r = 0.9611, p<0.001). Both Figures show that the size of the VFD cannot predict the driving performance of patients. However, due to the small number of participants in each subgroup, these results should be treated with caution and need further investigation.

Bottom Line: In addition, patients who passed the test performed more glances towards the area of their visual field defect.In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning.Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario.

View Article: PubMed Central - PubMed

Affiliation: Computer Engineering Department, Wilhelm-Schickard-Institute of Computer Science, University of Tübingen, Tübingen, Germany.

ABSTRACT
Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the central area of the visual field than patients who failed the test. In addition, patients who passed the test performed more glances towards the area of their visual field defect. In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning. Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario.

Show MeSH
Related in: MedlinePlus