Purchase this article with an account.
D.H. Reynolds, X.F. Wang, A. Iannaccone, A.J. Reiner, M.M. Jablonski; Age–Related Decline of the Submacular Vasoactive Neural Network . Invest. Ophthalmol. Vis. Sci. 2004;45(13):55.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose:Nitric oxide synthase (NOS)– and vasoactive intestinal polypeptide (VIP)–positive perivascular nerves form dense NOS– and VIP–positive submacular vasoactive neural networks (SVANNs) in the choroid. SVANNs are not observed in species that do not have a fovea, suggesting that SVANNs play a role in the fine regulation of choroidal blood flow (ChBF) in the macular region. An age–related ChBF decline has also been reported clinically. Therefore, the purpose of this study was to test the hypothesis that an attenuation of the SVANNs in the macula may be associated with aging. Methods:VIP–positive SVANN fibers were quantified in a blinded fashion in 3 groups of human donor eyes from healthy individuals: Group 1 (<45 years of age; n=2 eye pairs), Group 2 (45–65 years of age; n=4), and Group 3 (>65 years of age; n=4). Choroid samples were collected by taking a full–thickness 6 mm punch from the macular region, centered around the fovea. Immunohistochemistry was performed using anti–VIP antibodies and peroxidase–antiperoxidase immunostaining. VIP–positive SVANN fibers were quantified using NIH Image by determining the percent area of a vessel that was occupied by stained SVANN fibers in up to 12 different areas from each choroid punch. Results: Group 1 showed a mean vessel coverage of 21.03 ± 6.80% (SD), while groups 2 and 3 had percent vessel coverage of 11.47 ± 5.94% and 11.04 ± 5.02%, respectively. By one–way ANOVA, Group 1 had a significantly greater percent coverage than both Groups 2 and 3 (p<0.0001, in both cases). However, there was no statistically significant difference between Groups 2 and 3 (p = 0.7311). Conclusions: Our results are consistent with a significant VIP–positive SVANN decline after age 45 in healthy human donor eyes. These findings suggest that a decline in the neuronal control of ChBF may explain the reductions in ChBF observed clinically with aging.
This PDF is available to Subscribers Only