Subjective critical flicker fusion (CFF) helps to separate amblyopia from organic disease

Abstract

The examination of the critical flicker fusion (CFF) in the visual field center is a helpful tool in order to differentiate amblyopia from organic diseases such as maculopathies and neuropathies. A newly developed apparatus (4F) offers a simple and fast examination: ascending as well as descending thresholds of the foveal CFF can be determined. If central fixation is maintained, the test results are well reproducible. Different conditions show different results: normal thresholds or thresholds above normal are obtained in amblyopias, whereas they are below normal in maculopathies and neuropathies. In optic neuritis, CFF depends on the stage of the disease. There is no correlation between visual acuity and CFF in different conditions.

Key Words:

• Flicker fusion
• fixation
• amblyopia
• maculopathy
• neuropathy