Abstract
Purpose: :
To report on age-related changes in the foveal avascular zone (FAZ) and to relate these findings to the size of the FAZ in fellow eyes of patients with neovascular AMD in one eye.
Methods: :
25 fluorescein angiograms (5 per age category; < 30, 30-39, 40-49, 50-59 and > 60 years) were randomly extracted from an image repository in the Belfast Reading Centre if they showed a normal FAZ in at least one eye and no evidence of neovascular AMD (nvAMD) in either eye. A second set of 25 angiograms from patients with confirmed nvAMD in one eye and no AMD in the other eye was also selected. All angiograms were imported into an image grading platform and the area of the FAZ measured manually.
Results: :
With increasing age a rise in the area of the FAZ was noted 0.76 (+/- .15) to 1.32 (+/- 0.39), p for trend < 0.001. In unaffected fellow eyes of patients with nvAMD there was considerable variation in the area of the FAZ however on average it was significantly smaller ( 0.95 +/- 0.3) with age-matched controls (p < 0.05).
Conclusions: :
Although the FAZ increases in area with age, fellow eyes of patients with nvAMD in one eye have smaller FAZ suggesting that the foveal vasculature may growing inwards in response to hypoxic stimuli.
Keywords: age-related macular degeneration • imaging/image analysis: clinical • macula/fovea