Poster Q8 - Transient moods impact fall risk in people with glaucoma

Saturday, October 26, 2024

10:00 AM - 11:00 AM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

Natalie Bick

Graduate Student Researcher
University of Pittsburgh
Pittsburgh, Pennsylvania, United States

Co-Author(s)

HK

Helmet T. Karim, PhD (he/him/his)

Assistant Professor
University of Pittsburgh, United States
HA

Howard Aizenstein

Charles F. Reynolds III and Ellen G. Detlefsen Endowed Chair in Geriatric Psychiatry, Professor
University of Pittsburgh, United States
MR

Mark Redfern, PhD

Professor
University of Pittsburgh, United States

Last Author(s)

RC

Rakie Cham

Professor
University of Pittsburgh, United States

Introduction: Glaucoma is a complex disease with ophthalmological, neurological, sensorimotor, and psychological changes. One particular health concern is that people with glaucoma fall at a greater rate than similarly aged adults without glaucoma. Due to the high prevalence of glaucoma and its associated fall risk, we are seeking to understand fall mechanisms in this population. Though previous work has identified many risk factors, it is unclear how these factors such as depressive symptoms, balance and gait deficits, and visual impairments contribute to the increased fall rate in glaucoma. Specifically, the impact of mood on gait and balance in glaucoma has not been studied. The goal of this study was to understand how transient mood induction contributes to gait and balance changes in people with glaucoma. We hypothesized that gait and balance would be worse while participants reflected on sad memories compared to happy or neutral memories, and that individuals with glaucoma would be more impacted than those without.

Materials and

Methods: Twenty-one adults with glaucoma (G) between the ages of 65 and 85 years and seventeen similarly aged adults without (nG) were enrolled. Participants were asked to “Think of a time in your life when you felt extremely [happy or sad],” then rate how strongly they felt emotion during the memory on a scale of 1-5, where 1=no emotion and 5=extreme emotion. Participants recalled 4 happy and 4 sad personalized memories, termed induced transient mood (ITM) cues, each with a rating ≥3.
Participants walked at a comfortable pace along a straight walkway during 4 floor/lighting conditions: floor conditions were a hard and a soft floor; lighting conditions were well-lit and dim. Gait data were collected using a Vicon motion capture system. Gait speed was calculated from a marker on C7.
Balance testing was performed using the Bertec® CDP/IVR™ during 4 proprioception/vision conditions: proprioception conditions were fixed and sway-referenced (SR) floor; vision conditions were eyes open (EO) and closed (EC). Sway magnitude and velocity in the anterior-posterior direction were computed.
For each gait/balance condition, participants were asked to focus on a happy and sad memory (randomized), separated by a neutral fact. Each condition lasted 6 minutes, with the participant focusing on each ITM cue for 2 minutes. Mixed linear regression models were constructed within each gait/balance condition, with fixed effects ITM, patient group, and the first order interactions, with subject as a random effect. Dependent variables were gait speed, sway magnitude, and sway velocity, fit separately. Statistical significance was set at α=0.05.

Results, Conclusions, and Discussions: Results
Gait: During hard floor/well-lit, the G group walked significantly slower during the sad ITM than happy (F(2,65)=4.2 p=0.02), but the nG group did not have a significant ITM effect. During soft floor/dim-lit, soft floor/well-lit, and hard floor/dim-lit, G group had slower gait speed than nG (F(1,33)=5.0 p=0.03, F(1,33)=7.2 p=0.01, F(1,33)=4.1 p=0.05, respectively). Across participants, sad ITMs were slower than neutral in hard floor/dim-lit (F(2,66)=3.5 p=0.04), and slower than happy and neutral ITMs during soft floor/well-lit (F(2,66)=6.1 p=0.004).
Balance: During fixed/EO, group G had a significantly larger sway magnitude (F(1,36)=4.5 p=0.04). During fixed/EC, group G had significantly larger sway velocity (F(1,36)=4.2 p=0.05). During SR/EO, sway velocity was significantly faster during sad compared to neutral ITMs (F(2,70)=4.8 p=0.01) across both groups.
Conclusions
Gait speed, sway magnitude, and sway velocity are all sensitive to glaucoma-specific gait/balance changes. These metrics are all sensitive to the induced transient mood task. People with glaucoma were impacted by the sad ITM state during the simplest sensory condition, but those without glaucoma were not, highlighting a potential difference in the higher level neural processing in glaucoma. However, the ITM task did not differentiate balance behaviors between the two groups.
Discussion
Together, these results indicate that the relationship between emotions and sensory inputs may help us better understand fall risk in adults with glaucoma. By further understanding the role of psychological factors in gait/balance changes in people with glaucoma, we may ultimately find ways to reduce their fall risk related to mental health by developing alternate methods for gait/balance rehabilitation, such as incorporating strategies from cognitive behavioral therapy.

Acknowledgements (Optional): Bioengineering in Psychiatry T32 Fellowship (5T32MH119168-02) & Lendvay-Newton Balance Disorder Research Philanthropic Gift