Purchase this article with an account.
J. E. Grunwald, T. I. Metelitsina, J. C. DuPont, G.-S. Ying; Decreases in Choroidal Circulation Precede Choroidal Neovascularization (CNV) Formation and Visual Loss in Age Related Macular Degeneration (AMD). Invest. Ophthalmol. Vis. Sci. 2007;48(13):2153.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the association between choroidal circulatory abnormalities and the development of CNV and visual loss in AMD.
This is a longitudinal prospective study of a cohort of 137 AMD patients in which relative foveolar choroidal blood velocity (ChBVel), volume (ChBVol) and flow (ChBFlow) are assessed yearly using laser Doppler flowmetry (Oculix instrument). Of these patients, 101 had a year-1, 89 patients had a year-2, 87 patients had a year-3, 59 had a year-4, and 27 had a year-5 measurement. All study eyes had visual acuity of 20/40 or better and no choroidal neovascularization (CNV) at the time of enrollment. Appearance of CNV was assessed from fundus photographs by trained readers at the Photography Reading Center of the University of Pennsylvania. All data were analyzed in a masked fashion. Results are shown in arbitrary units (AU).
28 eyes developed CNV during the study. Baseline ChBVol and ChBFlow in these eyes at the beginning of the study were significantly lower by -24% (p=0.0001) and -21% (p=0.0007) than in the 165 eyes that did not develop CNV. No significant difference in ChBVel was detected. In 19 of these 28 eyes we had two circulatory measurements before the detection of CNV. During the year preceding appearance of CNV, 14 of these 19 eyes had decreases of 3.0% to 54% in ChBFlow. In the eyes that developed CNV, ChBVol and ChBFlow decreased by -9.6 ± AU and -11.5 AU before the development of CNV, while in eyes that did not develop CNV, they increased by 6.7 AU and 2.81 AU (univariate analysis, p=0.006 and p=0.004, respectively). Although we have little data on patients that have lost more than three lines of visual acuity, our results suggest that eyes with lower ChBFlow at baseline are 3 times more likely to develop a 3 line loss of vision than eyes with higher ChBFlow (univariate model, p=0.005).
Lower choroidal circulatory parameters at baseline are associated with higher risk of CNV development and visual loss. In addition, our results suggest that in AMD decreases in the foveolar choroidal circulation, and possibly ischemia, precede the development of CNV, just as in most of the other types of neovascularization throughout the body.
This PDF is available to Subscribers Only