Development of a multispectral imaging apparatus for cost-effective fundus disease detection.

Fundus spectral imaging (FSI) integrates fundus photography with spectral techniques, providing both spatial and spectral information for retinal imaging. Whereas existing FSI systems have demonstrated advantages in structural and functional imaging, their widespread adoption is hindered by high costs and complex optical designs. To address these challenges, we propose a low-cost multispectral fundus camera with a simplified optical design, built from off-the-shelf optics, 3D-printed parts, and equipped with fiber-bundle-coupled multi-wavelength LED illumination source (470-740 nm). Additionally, the proposed multispectral imaging apparatus incorporates a coaxial non-separated polarization-based reflection suppression technique, using orthogonal polarizers to suppress corneal reflections without pupil-plane separation. To the best of our knowledge, this is the first application of such an architecture in the context of FSI. Experimental results demonstrate that the developed system achieves high-quality FSI under low-cost conditions, validating its feasibility as a practical solution. Clinical validation validates its diagnostic capability for diabetic retinopathy, choroidal pigmented nevus, and, notably, the first reported spectral imaging of peripapillary atrophy. The system achieves performance comparable to conventional color fundus photography while enabling superior diagnosis of deep fundus conditions such as choroidal lesions, offering a cost-effective and practical FSI solution for broader deployment in resource-limited settings.