Purpose:The purpose of the study was to examine, whether there are
functional alterations of hemodynamics in the optic nerve head.
Methods: One randomly chosen eye of 87 healthy subjects (mean age 37,5y)
without any history of glaucoma or vascular disease was examined. The
laser-Doppler-flowmeter according to Riva was used for the measurements. The
measurements were performed at the nasal and temporal neuroretinal rim of the
optic nerve head, away from visible vessels. For statistical analysis a Pearson
correlation was calculated.
Results: The parameter velocity was (#1: temporal; #2: nasal) #1:
0,315±0,1 AU and #2: 0,286±0,1AU. The Pearson correlation coefficient between
age and velocity was #1: 0,49 and #2: 0,54. The correlation was statistically
significant #1: p=0.000001 and #2: p=0.0000006. The parameter volume was #1:
0,396±0,193 AU and #2: 0,533±0,381AU. The Pearson correlation coefficient
between age and volume was #1: -0,29 and #2: -0,34. The correlation was
statistically significant #1: p=0.006 and #2: p=0.001. The parameter flow was
#1: 9,636±3,001 AU and #2: 10,880±4,975AU. The Pearson correlation coefficient
between age and flow was #1: -0,04 and #2: -0,26. The correlation was
statistically not significant for #1: p>0.05 but was statistically
significant for #2: p=0.01.
Conclusions: These results might be explained by a decreasing vessel
diameter, which will lead to a reduced reserve capacity and an impaired
autoregulation.
1University Eye Hospital San Diego
2University Eye Hospital Hamburg, Germany