title: Age-related normal tolerance intervals for retinal vascular response to systemic autonomic nerve stimulation.
abstract: This study establishes the age-adjusted tolerance intervals for retinal vascular responses to sustained handgrip contraction (a test of sympathetic nerve function). Forty adult subjects (mean age: 39.7 +/- 14.1 years, range: 20 to 72 years; 19 males) were included in the final analysis. Mean percentage calibre change in response to sustained handgrip contraction in this population was -5.61% with a significant correlation between subject age and percentage retinal vessel calibre change (p less than 0.001). Mean retinal arteriolar calibre change in response to systemic autonomic stimulation varied significantly with age: between -8.48% at age 20 years and -2.06% at age 70 years with a mean of -5.95% at the mean age of 39.7 years. The standard deviation is 3.04% and the 95% confidence intervals were set between +/-6.17%. This autoregulatory reflex appears to be inversely related to age.
authors.affiliation: Moorfields Eye Hospital, London.
authors.forename: D W
authors.initials: DW
authors.lastname: Hill
authors.forename: L P
authors.initials: LP
authors.lastname: Lanigan
authors.forename: C V
authors.initials: CV
authors.lastname: Clark
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001160:Arterioles / Q000502:physiology; D001341:Autonomic Nervous System / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012171:Retinal Vessels / Q000502:physiology*; D014661:Vasoconstriction / Q000502:physiology