Multispectral imaging: Review of current applications.

Multispectral imaging (MSI) is a unique layer-by-layer imaging technique that allows the visualization of a wide array of retinal and choroidal pathologies including retinovascular disorders, retinal pigment epithelial changes, and choroidal lesions. Herein, we summarize the basic imaging principles and current applications of MSI together with recent technology advances in the field. MSI detects reflectance signal from both normal chorioretinal tissue and pathological lesions. Either hyperreflectance or hyporeflectance reveals the absorption activity of pigments such as hemoglobin and melanin and the reflection from interfaces such as the posterior hyaloid. Advances in MSI technique include creation of a retinal and choroidal oxy-deoxy map that could provide a better understanding of blood oxygen saturation within lesions as well as better interpretation of reflectance phenomenon of MSI images such as the different reflectance from the Sattler and Haller layers described in this review.