Alteration of travel patterns with vision loss from glaucoma and macular degeneration

Abstract

Importance: The distance patients can travel outside the home influences how much of the world they can sample and to what extent they can live independently. Recent technological advances have allowed travel outside the home to be directly measured in patients' real-world routines.

Objective: To determine whether decreased visual acuity (VA) from age-related macular degeneration (AMD) and visual field (VF) loss from glaucoma are associated with restricted travel patterns in older adults.

Design: Cross-sectional study.

Setting: Patients were recruited from an eye clinic, while travel patterns were recorded during their real-world routines using a cellular tracking device.

Participants: Sixty-one control subjects with normal vision, 84 subjects with glaucoma with bilateral VF loss, and 65 subjects with AMD with bilateral or severe unilateral loss of VA had their location tracked every 15 minutes between 7 am and 11 pm for 7 days using a tracking device.

Main outcomes and measures: Average daily excursion size (defined as maximum distance away from home) and average daily excursion span (defined as maximum span of travel) were defined for each individual. The effects of vision loss on travel patterns were evaluated after controlling for individual and geographic factors.

Results: In multivariable models comparing subjects with AMD and control subjects, average excursion size and span decreased by approximately one-quarter mile for each line of better-eye VA loss (P ≤ .03 for both). Similar but not statistically significant associations were observed between average daily excursion size and span for severity of better-eye VF loss in subjects with glaucoma and control subjects. Being married or living with someone and younger age were associated with more distant travel, while less-distant travel was noted for older individuals, African Americans, and those living in more densely populated regions.

Conclusions and relevance: Age-related macular degeneration-related loss of VA, but not glaucoma-related loss of VF, is associated with restriction of travel to more nearby locations. This constriction of life space may impact quality of life and restrict access to services.

Figure 1.. Schematic of Distance-Based Metrics

Schematic demonstrating the 2 distance-based metrics used for describing travel patterns: excursion size (maximum distance away from home) and excursion span. Three different excursion examples are shown: compact travel close to home (A), larger travel span close to home (B), and compact travel far from home (C). Comparing excursions A vs B, both excursions have the same excursion size; however, once away from home, excursion A is more compact (smaller excursion span) than excursion B. In A vs C, excursion C is further away from home; however, once away from home, both have the same excursion span. In B vs C, excursion C is further away from home than excursion B but also more compact so both excursions may have close to the same overall travel distance.

Figure 2.. Scatterplots of Daily Average Excursion Size

Scatterplots of daily average excursion size averaged for each person’s week of travel as a function of disease severity. A, Plot of visual acuity (logMAR) vs person mean average daily excursion size for the participants with age-related macular degeneration and control subjects. B, Plot of better-eye visual field (VF) mean deviation (MD) vs person mean average daily excursion size for those with glaucoma and control subjects.