Autofluorescence imaging captures naturally occurring fluorescence from ocular tissues, mainly the retina, without the need for injected dye. It is particularly sensitive to lipofuscin and other fluorophores in the retinal pigment epithelium.
Technique
Blue or near-infrared light is used to excite intrinsic fluorophores, and emitted light is recorded with specialised filters and cameras. The resulting images show areas of increased or decreased autofluorescence corresponding to metabolic activity or cell loss.
- Non-invasive and usually done with a confocal scanning laser ophthalmoscope
- Patterns vary among different macular and inherited retinal diseases
- Dark zones often reflect atrophy, while bright areas may indicate stressed cells
- Image quality can be affected by media opacities and fixation
Clinical Role
Autofluorescence helps diagnose and monitor conditions such as macular degeneration, Stargardt disease, and other dystrophies by revealing distribution of retinal pigment epithelium dysfunction. It complements structural OCT and colour photography.
- Useful in mapping geographic atrophy and tracking its expansion
- Characteristic signatures can assist in differentiating similar disorders
- Changes over time provide insight into disease progression
- Interpretation must consider normal age-related patterns
