Impact of age-related macular degeneration in patients with glaucoma: understanding the patients' perspective.

Abstract

The aim of the study is to measure the impact of age-related macular degeneration on vision-related activity limitation and preference-based status for glaucoma patients. This was a cross-sectional study. Two-hundred glaucoma patients of whom 73 had age-related macular degeneration were included in the research. Sociodemographic information, visual field parameters and visual acuity were collected. Age-related macular degeneration was scored using the Age-Related Eye Disease Study system. The Rasch-analysed Glaucoma Activity Limitation-9 and the Visual Function Questionnaire Utility Index measured vision-related activity limitation and preference-based status, respectively. Regression models determined factors predictive of vision-related activity limitation and preference-based status. Differential item functioning compared Glaucoma Activity Limitation-9 item difficulty for those with and without age-related macular degeneration. Mean age was 73.7 (±10.1) years. Lower better eye mean deviation (β: 1.42, 95% confidence interval: 1.24-1.63, P < 0.001) and age-related macular degeneration (β: 1.26 95% confidence interval: 1.10-1.44, P = 0.001) were independently associated with worse vision-related activity limitation. Worse eye visual acuity (β: 0.978, 95% confidence interval: 0.961-0.996, P = 0.018), high risk age-related macular degeneration (β: 0.981, 95% confidence interval: 0.965-0.998, P = 0.028) and severe glaucoma (β: 0.982, 95% confidence interval: 0.966-0.998, P = 0.032) were independently associated with worse preference-based status. Glaucoma patients with age-related macular degeneration found using stairs, walking on uneven ground and judging distances of foot to step/curb significantly more difficult than those without age-related macular degeneration. Vision-related activity limitation and preference-based status are negatively impacted by severe glaucoma and age-related macular degeneration. Patients with both conditions perceive increased difficulty walking safely compared with patients with glaucoma alone.