Purchase this article with an account.
John Lovasik, Helene Kergoat, Mireille Parent; Subfoveal Choroidal blood flow in senescence. Invest. Ophthalmol. Vis. Sci. 2013;54(15):4628.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The sub-foveal choroid is the sole blood supply for the cone photoreceptors within the foveal avascular zone (FAZ). A reduction in the sub-foveal choroidal blood flow (ChBF) has been reported before the onset of age-related macular degeneration, suggesting a cause-effect relationship. However, a reduction in ChBF can also be the consequence of a sub-clinical retinopathy in the FAZ, or increasing age per se. Thus, the interdependence among the ChBF and the structural integrity and function of the retina in the FAZ remains poorly defined. In the present study we quantified the effects of senescence on choroidal hemodynamics and its relation to central visual function.
20 healthy volunteers for each decade of life between 20 and 80 years of age participated in the study. The best corrected Snellen visual acuity (VA) was recorded during a complete eye exam for each subject. A confocal near infrared (780 nm) Laser Doppler Flowmeter was used to record ChBF (AU), velocity (ChBVel-kHz), and volume (ChBVol-AU) in the choriocapillaris within the FAZ at 25 Hz. Each subject was directed to fixate the center of the laser probe that appeared as a small dim red spot of light. Foveation of the laser spot was continued until a 10-20 sec interval with a constant DC output (indicating steady fixation) was obtained. The corresponding records of ChBF, ChBVel, ChBVol were cleaned of blink artifacts for each subject and then averaged over time. The mean values for all subjects were graphed as a function of subject age and a linear regression line drawn through each parameter to glean the effects of age on choroidal hemodynamics. An alpha value of 0.05 was used for statistical significance.
ChBVel decreased (r= -0.223, p= 0.02) while ChBVol increased (r= 0.222, p= 0.02) with age. In contrast, the ChBF remained constant with age (r= 0.005, p> 0.05). The group average ChBF across all age groups, Mean= 0.957 ± SD= 0.405, was associated with a central VA of 0.9 minarc ± SD= 0.14 across all subjects.
An acuity of 20/20 or better can be maintained in septuagenarians. The ChBF in the FAZ does not change between 20 to 80 years of age in healthy individuals. Because the ChBF varied by almost 100% within the 6 age groups studied, singular measurements of the ChBF cannot distinguish patients differing by just one or two lines from the standard 20/20.
This PDF is available to Subscribers Only