Near infrared (NIR) wavelengths penetrate through the retina and provide improved visibility and clarity of choroidal structures, assisting in rapid differentiation of deep fundus lesions.
The longer wavelengths used by the Annidis RHA system clearly show lesions such as nevi, melanomas and RPE hypertrophy. As an example, the images in Figure 1, below, show a nevus in the macular area using red (a) and NIR (b) wavelengths as compared to a traditional fundus photo (c). The RHA NIR image of the nevus (b) clearly shows a choroidal vessel as well as some drusen. A macular hole is also well visualized in the RHA red image (a) and is shown in the expanded view in (d).
Figure 1 (a)
Figure 1 (b)
Figure 1 (c)
Figure 1 (d)
The images in Figure 2, below, show views of congenital RPE hypertrophy (CHRPE), which is a benign thickening of the RPE, using both the Annidis RHA (a) and (c) as compared to traditional fundus photography (b) and (d). Figure 2 (c) clearly show the benefit of the NIR wavelength for detailed visualization of this disease process.
Figure 2 (a)
Figure 2 (b)
Figure 2 (c)
Figure 2 (d)
The enhanced visibility of pigmented fundus lesions using Annidis MSI is expected to aid in differentiating benign lesions from melanomas.