Mikroperimetrie

Mikroperimetrie, or microperimetry, is a diagnostic technique used to measure the light sensitivity of the retina at precise, localized points, while simultaneously imaging the fundus. It combines functional testing with real-time visualization of the retinal area being tested, allowing alignment of stimuli with specific retinal landmarks and compensation for eye movements.

During testing, a series of light stimuli of varying luminance is presented on a background illumination while an infrared fundus camera tracks fixation. The patient’s responses determine retinal sensitivity at each location, producing a threshold map. Eye-tracking and fixation monitoring enable accurate correlation between stimulus location and retinal anatomy, often demonstrated as a color-coded sensitivity map. Some systems also provide fixation stability indices and gaze metrics.

Output from mikroperimetry includes pointwise sensitivity values, mean sensitivity for regions or grids, and fixation analysis. The results are commonly integrated with structural imaging, such as optical coherence tomography, to relate functional data to retinal layers and lesions. Stimulus size, duration, and testing patterns can vary across devices, allowing flexible assessment of macular function.

Indications for mikroperimetry include evaluation of macular diseases (for example, age-related macular degeneration, diabetic macular edema, macular dystrophies), monitoring progression, assessing functional changes after treatment, and guiding rehabilitation or low-vision strategies. Limitations include dependence on patient cooperation and fixation ability, potential variability between devices, and the need for interpretation within the context of structural imaging. Microperimetry complements standard perimetry by focusing on central retinal function and fixation behavior.