Perifoveal Vessel Count as a Function of Age in the Healthy Human Eye

Abstract

Purpose: : To our knowledge, only one study (Ibrahim et al 1998) examined the interaction between senescence and the number of perifoveal vessels in the living human eye. That study reported a loss of 0.3 perifoveal vessels for each half decade of life between 55 to 74 yrs of age. In the present study, our objective was to reevaluate the perifoveal vessel number in a cohort of healthy volunteers representing a much broader age range.

Methods: : Eighty-six healthy non-smoking adults between 20 and 80 years of age participated in this study. A high-resolution digital color fundus camera system (Visualis by Imedos) was used to acquire 30° images for the right eye of each subject. After photography, a green filter was used to increase the contrast of vessels against the fundus background. Each image was magnified to optimize vessel counting on a large monitor. The central 15° area was divided into two circular zones. The first circumscribed the fovea with a circle whose diameter was equal to the horizontal diameter of the subject’s optic nerve head. The radius of the second circle was increased by the radius of the first circle. Allvessels within the annulus delimited by the first and second circles were counted for this study.

Results: : The mean number of perifoveal vessels in our population was 13.4 ± 0.2 (Mean ± SEM). The number of perifoveal vessels for each subject was also plotted as a function of subject age. A linear regression line through the data points indicated that the number of vessels within the macular zone did not vary with age (p= 0.5465).

Conclusions: : Our measurements did not reveal any loss of perifoveal vessels in the ocular fundus of healthy subjects between 20 and 80 years of age. The difference between the present study and that of Ibrahim et al may be attributed to the fact that the cardiovascular health of each subject was determined to be normal, and that none of our subjects were smokers.

Keywords: aging • blood supply • macula/fovea