Abstract
Purpose :
Microvascular dysfunction in the retina may reflect changes in the brain related to aging and neurodegeneration, making quantitative assessment of retinal blood flow a potentially powerful biomarker for these conditions. Further, microvascular flow may be related to age-related cognitive and functional decline. The purpose of this study is to assess the relationship between ocular blood flow and aging as well as with function.
Methods :
A cross sectional study of healthy control subjects over 50 years of age was conducted. Subjects were enrolled via online advertisement and underwent a screening eye exam. Subjects enrolled had no history of diabetes, hypertension, rheumatoid arthritis, and no evidence of ocular disease. Patients who scored less than 24 on the Mini Mental Status Exam were excluded. Ocular testing included spectral domain optical coherence tomography (SD-OCT), OCT Angiography, laser speckle contrast imaging (LSCI). A Trail Making Test B (TMTB), closed Romberg and Timed Up and Go (TUG) test were used as measures for both cognition and balance. Nailfold Video Capillaroscopy (NVC) was utilized to measure peripheral blood flow velocity. Pearson correlation tests were utilized to evaluate the relationship between age and functional testing as well as between age and blood flow variables.
Results :
Thirteen subjects were enrolled in this study. Age correlated strongly with the functional variables tested resulting in increased time for the TUG (r =.74, p = 0.02 ) and TMTB (r =.82 p < 0.01), and shorter times on the closed Romberg (r = 0.83, p < 0.01).) Similarly, age correlated with decreased nailfold capillary flow (r = 0.64, p = 0.04). Mean retinal BFVi was correlated with age, but this did not meet statistical significance (r = 0.49, p = 0.055).
Conclusions :
As expected, cognition and balance testing declined with age. As age increases time to complete TUG and TMTB increased and time for closed Romberg decreased. Peripheral microvascular blood flow in the nailfold decreases with age. Further recruitment will allow for comparisons between functional testing and retinal and peripheral blood flow.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.