Abstract
PURPOSE: To examine if changes in hemodynamic measures during an orthostatic challenge were associated with progression of age-related macular degeneration (AMD) over a 4-year period in The Irish Longitudinal Study on Ageing. METHODS: Participants with AMD who underwent an active stand (AS) test at wave 1 (2009/2010) and retinal photographs at both wave 1 and wave 3 (2014/2015) were included (N = 159: 121 with no AMD progression and 38 with progression). Beat-to-beat hemodynamic data were non-invasively collected using a Finometer MIDI device during the AS at wave 1, recording systolic blood pressure (sBP), diastolic blood pressure (dBP), mean arterial pressure (MAP), and heart rate. Cardiac output, stroke volume, and total peripheral resistance (TPR) were derived from these measures. Baseline characteristics were compared between groups with and without AMD progression. Mixed-effects linear regression models were used to assess the association between changes in hemodynamic parameters during the AS and AMD progression, controlling for known AMD-associated risk factors. RESULTS: At baseline, increasing age and lower dBP were significantly associated with AMD progression. Mixed-effects models for the period between standing and 10 seconds post-stand revealed significant associations with AMD progression with a steeper drop in dBP and a slower drop in TPR. Between 10 and 20 seconds post-stand, AMD progression was significantly associated with less pronounced reduction in heart rate. CONCLUSIONS: These observational data suggest that impaired hemodynamic responses within the first 20 seconds of orthostasis may be associated with the progression of AMD.