Development and first assessment of a RGBW-LED diaphanoscope

Background: Diaphanoscopy is an old but still useful technique in ophthalmic diagnostics. Its application suffers somewhat from the fact that the light is strongly attenuated and red-shifted in color when the eye wall is transilluminated. Material and methods: A color adjustable diaphanoscope prototype is developed based on a powerful red-green-blue-white light-emitting diode (RGBW-LED). Its optical and thermal properties are measured and tested on the porcine eyes of a local butcher. In addition, based on the technical data, the assumed retinal hazard to human eyes is assessed according to the standard DIN EN ISO 15004-2: 2007-6. Results: The investigated porcine eyes were brightly illuminated with all LED colors. The calculated values for judging the thermal and photochemical hazard were below the limits given in DIN EN ISO 15004-2: 2007-6. Conclusion: Based on the standard mentioned above, there is no recognizable danger to the human retina when applied for a limited time, and at least in the porcine model, the presented RGBW-LED diaphanoscope allows an adjustable ophthalmological transillumination without the requirement of the more elaborated devices that are usually employed in operating rooms.