Effects of Glaucoma
on path integration
in virtual reality
M.A. Safa Andac
M.Sc. Francie Kramer
Advisor: Prof. Dr. Michael Hoffmann
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 955590.



Outline


- Damage to the Retinal Ganglion Cells
- Progressive -- Blindness
BaCKGROUND: GLAUCOMA


Hoste A.M., 2003


Collett, T. S., & Graham, P. (2004)
Daga et al. (2017) - Navigation and Glaucoma
BaCKGROUND: NAVIGATION


Ability to keep track of a position
- Vestibular system (Wallace et al., 2002)
- Sensory flow (optic-flow) (Wylie et al., 1999)
- Motor efference (Whishaw and Wallace, 2003)
https://www.bi.mpg.de/opticflow

BaCKGROUND: OPTIC FLOW


Safer

Manipulable

Immersive

BaCKGROUND: VIRTUAL REALITY


[H1] Glaucoma patients are slower than control group in path following
[H2] Participants move slower in an environment without optic flow
[H3] Control group benefit from optic flow more
HYPOTHESES


- 29 participants (15 control, 14 glaucoma)
- Environment with/out optic flow (w OF // w/o OF)


METHODS


- Start from Point 0
- Move to Point 1
- Remember the position
- Move to Point 2 (second waypoint)
- Move to Point 3 (final waypoint)
- Point the position to be remembered
METHODS: PaTH iNTEGRATION


1
2
3
0
METHODS: PaTH iNTEGRATION


Measures
- Travel Time
- Pointing Task Duration
- Error distance btw expected location - response location
Statistics
Mixed-ANOVA with factors
- Group
- Optic Flow
- Group x Optic Flow
- Start from Point 0
- Move to Point 1
- Remember the position
- Move to Point 2 (second waypoint)
- Move to Point 3 (final waypoint)
- Point the position to be remembered
1
2
3
0
RESULTS

w/o OF
OF
Factor | p |
---|---|
Group | < 0.01 |
Optic Flow | 0.03 |
Group x Optic Flow | 0.14 |
w/o OF
OF


- Control Group is faster
- Groups are slow in the environment with optic flow
RESULTS

Factor | p |
---|---|
Group | < 0.01 |
Optic Flow | 0.03 |
Group x Optic Flow | 0.14 |
w/o OF
OF
w/o OF
OF


Factor | p |
---|---|
Group | 0.02 |
Optic Flow | < 0.01 |
Group x Optic Flow | 0.58 |
RESULTS

w/o OF
OF
w/o OF
OF


- Control Group is faster
- Groups are slow in the environment with optic flow
Factor | p |
---|---|
Group | 0.02 |
Optic Flow | < 0.01 |
Group x Optic Flow | 0.58 |
RESULTS

w/o OF
OF
w/o OF
OF


Factor | p |
---|---|
Group | 0.19 |
Optic Flow | 0.02 |
Group x Optic Flow | 0.04 |
RESULTS

Undershoot
Overshoot
w/o OF
OF
w/o OF
OF


Factor | p |
---|---|
Group | 0.19 |
Optic Flow | 0.02 |
Group x Optic Flow | 0.04 |
RESULTS

Undershoot
Overshoot
w/o OF
OF
w/o OF
OF


Factor | p |
---|---|
Group | 0.09 |
Optic Flow | < 0.01 |
Group x Optic Flow | 0.10 |
RESULTS

w/o OF
OF
w/o OF
OF


- No difference between groups
- Accuracy improves in the environment with optic flow
RESULTS

w/o OF
OF
w/o OF
OF
Factor | p |
---|---|
Group | 0.09 |
Optic Flow | < 0.01 |
Group x Optic Flow | 0.10 |


Factor | p |
---|---|
Group | 0.48 |
Optic Flow | < 0.01 |
Group x Optic Flow | 0.32 |
RESULTS

w/o OF
OF
w/o OF
OF


RESULTS

w/o OF
OF
w/o OF
OF
Factor | p |
---|---|
Group | 0.48 |
Optic Flow | < 0.01 |
Group x Optic Flow | 0.32 |


SUMMARY


[H1] Glaucoma patients are slower than control group in path following
[H2] Participants move slower in an environment without optic flow
Participants move slower in an environment with optic flow
[H3] Control group benefits from optic flow more
All groups benefit from optic flow similar
- Insecurity in glaucoma patients
- Accuracy improvement in the environment with optic flow
- Trade-off between time and accuracy
DISCUSSIOn


SECONDMENT



- X position
- Y position
- Heading Direction
{
$$ x_t $$
- Is there a behavioral difference during navigation?
- Does optic flow affect the behavior?
Research Questions

1
2
3
ACKNOWLEDGEMENT
THANKS!
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 955590.




Aging, Cognition
& Technology Group
Visual Processing Lab

Matthieu Bernard
Vladislava Segen
Prof. Thomas Wolbers
Khaldoon Al-Nosairy
Gokulraj Prabhakaran
Yaxin Hu
Prof. Erhadt Barth
Genova-Presentation
By Safa Andac
Genova-Presentation
- 72