Versatile illumination module for multispectral imaging with a conventional fundus camera

Retinal imaging has always played a major role in the detection and management of ocular disease and a wide range of retinal imaging techniques exist. Most of them, however, focus only on high image quality (field, 2D or 3D resolution) but neglect spectral information. The aim of this study was to develop a versatile lighting module in order to easily perform multispectral imaging with a conventional fundus camera. Taking advantage of the development of multi-color LEDs, we have built a source with 8 LEDs allowing to take images in white light and at 7 wavelengths ranging from 395 to 730nm. The LEDs fit on a surface of 33mm2 and are electronically controlled via an Arduino module. The design of the source allows it to be easily positioned in a conventional camera to replace the lighting bulb. The illumination module was tested in a TOPCON-TRC-NW6S fundus camera using a model eye. The proximity of the LEDs makes it possible to obtain a good optical image without additional modification of the system. This low-cost device makes it possible to easily modify a wide range of classic camera into a multispectral camera in order to more easily explore the potential of this technique.