[The retinal visual acuity of amblyopia].

The authors studied the relationship between the retinal visual acuity (grating acuity) and recognition acuity (E acuity) in 94 normal eyes and 169 amblyopic eyes with the results that the RVA in 84% of the normal eyes was the same as E acuity, while in 66% of the amblyopic eyes, especially the strabismic category, RVA was better than E acuity. RVA was not affected by the orientation (0 degrees, 45 degrees, 90 degrees, or 135 degrees) of the grating or the size of the light field (1.5 degrees or 3.5 degrees). Factors which could contribute to the difference between the RVA and the E acuity and the difference between strabismic and refractive amblyopia were discussed. It was put forward that grating acuity was reliable in the diagnosis of amblyopia.