EFFECT OF AGING ON RETINAL MACULAR MICROCIRCULATION - A BLUE FIELD STIMULATION STUDY

Purpose. Structural changes in the retina are known to occur with agin g. This study was performed to investigate whether aging also affects the retinal macular microcirculation. Methods. Healthy volunteers with ages ranging from 20 to 78 years (mean +/- SD, 49 +/- 19 years) were included in this study. The retinal macular microcirculation was asses sed with the blue field simulation technique, based on the blue field entoptic phenomenon. Subjects were asked to match the velocity and den sity of computer-simulated particles displayed on a screen with those of their entoptically observed leukocytes. Ten matching trials were pe rformed, and an average leukocyte velocity and density were calculated . Results. Significant negative linear correlations were observed betw een velocity and age (P 0.0001) and density and age (P = 0.009). Older subjects (50 to 78 years of age) had a significantly slower velocity (0.61 +/- 0.21 mm/s) and smaller density (90 +/- 43 particles per fiel d of view) than younger subjects (0.92 +/- 0.12 mm/s and 135 +/- 65 pa rticles, respectively; unpaired Student's t-test, P = 0.001 and P = 0. 01, respectively). Conclusions. These results suggest that, in normal subjects, retinal macular blood flow decreases with age. The 20% decre ase in average velocity with age is very similar to the age-related de crease in number of cells observed in the human foveal ganglion cell l ayer.