Wide-field smartphone fundus photography using trans-pars-planar illumination and miniaturized indirect ophthalmoscopy (Conference Presentation)

Abstract

It is known that wide-field fundus photography is essential for screening, diagnosis and treatment evaluation of eye diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), retinopathy of premature (ROP), etc. However, the high equipment cost of existing devices is a limiting factor for clinical deployment of wide-field fundus photography, particularly in rural and underserved areas where both expensive instruments and skilled operators are not available. Low-cost smartphone fundus cameras promise convenient assessment of eye diseases at point-of-care environments, and may also enable affordable telemedicine screening to foster the access to medical cares in rural and underserved areas. However, practical application of existing smartphone fundus cameras is limited by the small field of view (FOV) in single-shot images. We have recently demonstrated the feasibility of trans-pars-planar illumination, i.e., delivering illuminating light through pars plana outside of the pupil. By freeing the whole pupil for image purpose only, the trans-pars-planar illumination provides one unique opportunity to develop snapshot, low-cost, but high-quality wide-field fundus camera. Using all off-the-shelf parts, a smartphone-based prototype fundus camera was constructed to achieve a 152-degree FOV in single-shot images, without the need for pharmacological pupil dilation. Moreover, we have also explored miniaturized indirect ophthalmoscopy to achieve wide-field fundus video photography. A totally wireless smartphone fundus camera was constructed, with a whole weight of 255 g. This device allowed both snapshot fundus photography and continuous video recording.