Abstract
Clinical studies of amblyopia typically focus on unilateral amblyopia associated with anisometropia and/or strabismus. However, astigmatism, which is present in approximately 15% of U.S. school children (with higher prevalences among Asians, Hispanics and members of some Native American tribes), is also associated with reduced best-corrected vision and stimulus orientation dependent deficits, i.e., meridional amblyopia. In this presentation, we summarize the results of recent studies of amblyopia associated with uncorrected bilateral astigmatism in terms of 1) the patterns of visual deficits that result from uncorrected astigmatism in early development (recognition acuity, stereo acuity, and grating acuity, vernier acuity, and contrast sensitivity for stimuli of various orientations), 2) the sensitive period for development of astigmatism-related amblyopia, and 3) the sensitive period for successful treatment of astigmatism-related amblyopia. Results are also discussed with regard to recent findings on patterns of deficits observed in other forms of amblyopia and treatability of other forms of amblyopia in older children and adults.