Multispectral imaging records retinal or anterior segment images at several discrete wavelengths, providing more spectral information than standard colour photography. It can highlight different tissue components and vascular features.
Principles
Cameras capture sequences of images using narrow-band filters or tunable light sources. Each wavelength emphasises particular chromophores such as haemoglobin, melanin, or macular pigment.
- Produces sets of images that can be combined or analysed separately
- Helps distinguish structures that appear similar in white light
- May allow estimation of oxygenation or pigment density
- Requires calibration and stable imaging conditions
Applications
Multispectral techniques are being explored for improved detection of retinal vascular disease, macular pigment distribution, and early degenerative changes. They may support screening and research into tissue metabolism.
- Potential to reveal subclinical pathology not seen on standard photos
- Often combined with automated analysis algorithms
- Currently more common in research than routine practice
- Interpretation must consider normal spectral variability among individuals
