
Canberra, Australia-Spatial frequency doubling (FD) stimuli have an excellent ability to predict progression of visual field loss and optic disc abnormalities for about 3 years in patients with glaucoma, but the predictive power of one assessment on its own drops off over time, said Ted Maddess, PhD, a senior fellow (associate professor) in the visual sciences group, Research School of Biological Sciences, Australian National University, Canberra, Australia.