WIDE-FIELD SMARTPHONE FUNDUS VIDEO CAMERA BASED ON MINIATURIZED INDIRECT OPHTHALMOSCOPY
Fundus examination is important for retinal disease screening, diagnosis, and treatment evaluation. In coordination with widely available internet technology, digital fundus photography has gained increasing interest for telemedicine examination of retinal diseases.1 Low-cost smartphone fundus cameras have been developed to explore affordable telemedicine of diabetic retinopathy, age-related macular degeneration, retinopathy of premature, etc. Most of these smartphone fundus cameras use the configuration of indirect ophthalmoscopy. By directly adopting binocular indirect ophthalmoscopy lenses, these smartphone fundus cameras provide a low-cost solution for retinal examination. However, the binocular indirect ophthalmoscopy lenses are specially designed for head-mounted binocular indirect ophthalmoscopy systems, which require long distance from the lens to the smartphone camera. Therefore, the binocular indirect ophthalmoscopy lens–based smartphone fundus cameras are bulky, with a small field of view (FOV), typically <45o in single-shot images. We report in this study a unique design of miniaturized indirect ophthalmoscopy to achieve 92o FOV in single-shot fundus image and to allow continuous video recording which opens the opportunity for real-time involvement of experienced ophthalmologists remotely.