Purpose There is evidence that people with glaucoma exhibit difficulties with some complex visual tasks such as face recognition, motion perception and scene exploration. The purpose of this study was to determine whether glaucoma affects the ability to categorise briefly presented visual objects in central vision.
Methods Visual categorisation performance of 14 people with glaucoma (primary open angle glaucoma and preperimetric) and 15 age-matched controls was measured, assessing both accuracy and response times. Grey level photographs of objects (size) were presented for 28 ms foveally. Perimetric thresholds were normal for all participants within the central 3°. Two levels of contrasts were included: one medium level at 50% and one with high contrast at 100%.
Results On average, accuracy was significantly decreased by 7% (p=0.046) for the medium contrast stimuli in patients with glaucoma (87% of correct response, SD: 5%) compared with controls (94% of correct response, SD: 4.7%). Group average response times were significantly slower for the patients relative to the control group (712 ms, SD: 53 ms compared with 643 ms, SD: 34 ms for the control group; p<0.01). Performance was equivalent in the two groups when the picture contrast was 100%.
Conclusions The impairment observed in the categorisation task supports previous work that demonstrates that people with glaucoma can have greater difficulties with complex visual tasks than is predicted by their visual field loss. The performance was equivalent to age-matched controls when contrast was maximised.
- Visual perception
- Visual pathway
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Contributors QL: substantial contributions to the conception or design of the work, analysis and interpretation of data. Drafting, writing the work and revising it critically for important intellectual content. JJL: drafting the work or revising it critically for clinical data, collected data, provided and cared for study patients, revising it critically for important intellectual content. AMMcK: substantial contributions to the experiment, analysis and interpretation of data. Drafting, writing the work and revising it critically for important intellectual content.
Funding This work was supported by the Centre National de la Recherche Scientifique (CNRS), grant number (PICS-CNRS 2015).
Competing interests None declared.
Ethics approval UoM Human Research Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.