Wide-Field Smartphone Fundus Video Camera Based on Miniaturized Indirect Ophthalmoscopy

Abstract

Purpose This study is to develop a low-cost, easy-to-use, wide-field smartphone fundus video camera to enable affordable point-of-care examination and telemedicine. Methods The wide-field smartphone fundus camera is based on a unique design of miniaturized indirect ophthalmoscopy. For proof-of-concept prototype, we used a Samsung Galaxy S6 smartphone and all off-the-shelf components. A fiber coupled LED was used to deliver illumination light through a 1 mm micro mirror, which was conjugated to the subject pupil plane, for retinal illumination. A 60D ophthalmic lens was used to image the retina through the eye, and a plano-convex lens with 90 mm focal length was used to relay the retinal image to the smartphone camera. Results 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. 92° field of view (FOV) was achieved in single-shot images. Optic disc, macula, and retinal blood vasculatures can be clearly observed with image quality comparable to standard fundus camera. Conclusion Miniaturized indirect ophthalmoscopy enabled a low-cost, portable, wide-field smartphone fundus camera, which can foster telemedicine and clinical deployments of wide-field fundus photography for eye disease screening, diagnosis and treatment assessment.

Detection of retinal abnormalities using smartphone-captured fundus images: a survey

“…We distinguish that approach is proposed to capture multi-field fundus images. In [37], a three single-shot images was performed and then merged in order to achieve an FOV equal to 92°, as shown in figure1.(c). In [34], five 50° FOV images are captured in rapid sequence where orientation are respectively of the central, inferior, superior, nasal, and temporal retina.…”

“…Thereafter, the images were merged to provide a 152° view. In [37], the authors pretend that a real time 180° FOV image providing can be achieved through a collaborative work based on ophthalmologist experience and improved montage data processing. However, wide-field of view employment is limited by the processing execution time.…”

Diagnostic Images of the Ocular Fundus Using a Low-Cost Portable Endoscope in Premature Patients at Risk of Developing Retinopathy of Prematurity

“…Similarly, since 2012, smartphones have been used with 20, 28, 30, 40, and 60 D ophthalmic lens, to examine the fundus, and are safe for use in humans [8,9].…”

Near-infrared light-guided miniaturized indirect ophthalmoscopy for nonmydriatic wide-field fundus photography

“…However, clinical deployments of the transpalpebral illumination-based device are still challenging due to the requirement of separate adjustment and optimization of imaging and illumination sub-systems. We have previously demonstrated a miniaturized indirect ophthalmoscopy-based smartphone fundus camera with a 61° external angle (92° eye angle) FOV [17,18]. This laboratory prototype device ismydriatic and requires pharmacological pupillary dilation.…”

“…Instead of using a single visible LS as in our previous mydriatic prototype [17], the LS used in this nonmydriatic device consists of two illuminators: a near-infrared (NIR) [central wavelength, 850 nm] light-emitting diode (LED) (M850LP1, Thorlabs Inc., Newton, NJ) for preview mode imaging, i.e., for retinal positioning and focus adjustment; and a white LED (MWWHL4, Thorlabs Inc., Newton, NJ) for color retinal imaging. The NIR and white LEDs are coupled into one optical fiber [Fig.…”