Flicker perimetry assesses visual field sensitivity using flickering rather than static light stimuli. It can be more sensitive to certain types of retinal or optic nerve dysfunction.
Method
Targets within the visual field alternate between light and dark at specific frequencies and contrasts. The patient responds when flicker is perceived, allowing threshold measurement across test locations.
- Often uses high-frequency flicker that minimises influence of optical blur
- Can target magnocellular pathways involved in motion and temporal processing
- Test duration and fatigue must be managed carefully
- Requires calibration of luminance and frequency for reliable results
Clinical Use
Flicker-based tests have been explored for early glaucoma detection and assessment of optic nerve disease. They may reveal dysfunction before standard static perimetry shows clear defects.
- Provides complementary information to conventional threshold tests
- Interpretation still relies on comparison with normative databases
- Use in routine practice varies by centre and equipment
- Further research continues to refine protocols and clinical value
