Gait in Elderly Glaucoma: Impact of Lighting Conditions, Changes in Lighting, and Fear of Falling

Abstract

Purpose: The purpose of this study was to characterize the impact of lighting changes on gait in elderly patients with glaucoma and evaluate whether associations are mediated by fear of falling (FOF).

Methods: Gait initiation and parameters measured with the GAITRite Electronic Walkway were captured in normal indoor light, then in dim light, and again in normal light (normal post dim [NPD]). Participants' right and left eye visual fields (VFs) were merged into integrated VF (IVF) sensitivities. FOF was evaluated using a Rasch-analyzed questionnaire. Multivariable regression models evaluated whether IVF sensitivity was associated with lighting-dependent gait changes and if this relationship was mediated by FOF.

Results: In 213 participants (mean age = 71.4 years), gait initiation in dim light took longer with more VF damage (P = 0.02). Greater VF damage was associated with slower gait in dim (P < 0.001) and NPD (P = 0.003) lighting, as well as shorter strides (P = 0.02), broader stance (P = 0.003), and more variable stride velocity and length in all lighting (all P < 0.03). When moving from normal to dim lighting, those with more VF damage slowed gait and cadence, shortened stride length, and lengthened double support time (all P < 0.001). Velocity, cadence, and double support time did not return to baseline in NPD lighting (all P < 0.05). Fear of falling did not appear to mediate the relationship between IVF sensitivity and lighting-dependent gait changes.

Conclusions: Patients with more VF damage demonstrate gait degradation in extreme or changing lighting, which is not mediated by FOF.

Translational relevance: Quantitative spatiotemporal gait evaluation reveals lighting-associated impairment, supporting patient-reported difficulty with nonideal lighting and equipping providers to advise patients about limitations.

Keywords: fear of falling (FOF); gait; glaucoma; lighting; visual field (VF).

Figure 1.

Association between a 5 db decrement in IVF sensitivity and the time to gait initiation under different lighting conditions, as well as the difference in time to gait initiation between consecutive lighting conditions. Values presented come from separate multivariable models that controlled for age, race, gender, comorbidities, and polypharmacy. IVF = integrated visual field; dB = decibel; ∆ = delta; p = significance level.

Figures 2.

(A) Gait parameters and (B) gait coefficients of variation. Association between IVF sensitivity and gait parameters and coefficients of variation under different lighting conditions. Values presented come from separate multivariable models that controlled for age, race, gender, comorbidities and polypharmacy. A positive z-score represents a higher numeric value for the analyzed metric. IVF = integrated visual field; dB = decibel, β = regression coefficient; p = significance level; pct = percent cycle time; CV = coefficient of variation.

Figure 3.

(A) Difference in gait parameters and (B) difference in gait coefficients of variation. Association between IVF sensitivity and the difference in gait parameters and gait coefficients of variation between different lighting conditions. Values presented come from separate multivariable models that controlled for age, race, gender, comorbidities, and polypharmacy. A positive z-score unit increment represents a higher numeric value for the analyzed metric. IVF = integrated visual field; dB = decibel; β = regression coefficient; p = significance level; pct = percent cycle time; CV = coefficient of variation.