Local variations in the optical properties of thick In0.13Ga0.87As films grown on GaAs(001) substrates misoriented toward {111} planes have been studied with polarized and spectrally-resolved cathodoluminescence (CL) imaging. The degree of anisotropic relaxation and density of dark line defects (DLDs) in CL was found to depend on the choice of the substrate miscut orientation. An enhanced anisotropy in DLD density and strain relaxation was found for a misorientation towards (111)A relative to that for a misorientation towards (111)B. Local variations and spatial correlations in polarization anisotropy, band-gap energy shifts, luminescence efficiency, and defect-induced long-wavelength luminescence were examined.