DETERMINATION OF CRITICAL (FOVEAL) FLICKE R FUSION FREQUENCY (CFF) HELPS TO SEPARATE ORGANIC-DISEASE FROM (ORTHOPTIC) AMBLYOPIA

Purpose To measure critical (foveal) flicker fusion frequencies (CFF) in normal eyes, unilateral maculopathies and neuropathies and in ortho ptic amblyopias.Methods A newly developed apparatus (4F) with LED's me asured subjective foveal CFF by ascending and descending mode in a gro up of normals and patients. Results The apparatus (4F) measures tempor al resolution. Foveal CFF ist more reduced in neuropathies than in mac ulopathies. In contrast, CFF in amblyopic eyes is hardly reduced, in m ost cases equal or better than in the dominant fellow eye. This is ind ependent from the visual acuity of the amblyopic eye. Conclusion CFF t esting is useful in the evaluation of unexplained (unilateral) reducti on of visual acuity. A dissociation between visual acuity and CFF (wit hin normal range) is present in cases of amblyopia.