Reduced peripheral vision in glaucoma and boundary extension

ABSTRACT

Clinical relevance

Peripheral vision is known to be critical for spatial navigation. However, visual cognition, which impacts peripheral vision, has not been studied extensively in glaucoma.

Background

Spatial memory was assessed with a known to induce a robust memory distortion called “boundary extension” in which participants erroneously remember seeing more of a scene than was present in the sensory input.

Methods

Fifteen patients with glaucoma and 15 age-matched normally sighted controls participated in the experiment. Participants were shown 10 photographs of natural scenes randomly displayed for 0.5 s or 10 s. Following each scene, the participant was asked to draw it from memory.

Results

On average, boundary extension was larger, by 12%, for patients than for controls, but the difference was significant for 4 photographs. Patients tended to add more space between the object and the edges than there was between the objects and the border of the photograph. A control experiment in which participants were asked to draw isolated objects without scene context resulted in a significant reduction of the memory distortion in both groups, but patients still drew the objects smaller than controls.

Conclusion

The reduced field of view in glaucoma has an impact on spatial memory for scenes and on perception of size.

KEYWORDS:

• Boundary extension
• glaucoma
• scene perception
• size
• spatial memory

Acknowledgements

The study was funded by a research grant from the Fondation Visio and from the Société Française du Glaucome. The sponsors had no role in the design or conduct of this research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Société Française du Glaucome [SFG 2015]; Fondation VISIO [VISIO 2015].