Simple, inexpensive technique for high-quality smartphone fundus photography in human and animal eyes

Abstract

Purpose. We describe in detail a relatively simple technique of fundus photography in human and rabbit eyes using a smartphone, an inexpensive app for the smartphone, and instruments that are readily available in an ophthalmic practice. Methods. Fundus images were captured with a smartphone and a 20D lens with or without a Koeppe lens. By using the coaxial light source of the phone, this system works as an indirect ophthalmoscope that creates a digital image of the fundus. The application whose software allows for independent control of focus, exposure, and light intensity during video filming was used. With this app, we recorded high-definition videos of the fundus and subsequently extracted high-quality, still images from the video clip. Results. The described technique of smartphone fundus photography was able to capture excellent high-quality fundus images in both children under anesthesia and in awake adults. Excellent images were acquired with the 20D lens alone in the clinic, and the addition of the Koeppe lens in the operating room resulted in the best quality images. Successful photodocumentation of rabbit fundus was achieved in control and experimental eyes. Conclusion. The currently described system was able to take consistently high-quality fundus photographs in patients and in animals using readily available instruments that are portable with simple power sources. It is relatively simple to master, is relatively inexpensive, and can take advantage of the expanding mobile-telephone networks for telemedicine.

Figure 1

Filmic Pro app allows independent control of light intensity (red light bulb), exposure (green circle), and focus (blue square) while filming. Video library access (blue arrow).

Figure 2

Filming setup with user holding iPhone for filming with Filmic Pro app in one hand and holding 20D lens for focusing on the retina in the other hand.

Figure 3

Retinoblastoma (partially treated) imaged during examination under anesthesia.

Figure 4

Familial exudative vitreoretinopathy imaged during examination under anesthesia.

Figure 5

Vasculitis imaged in emergency department setting.

Figure 6

Large choroidal nevus imaged in the emergency department setting.

Figure 7

Control rabbit eye.

Figure 8

Experimental rabbit eye with induced total retinal detachment and severe proliferative vitreoretinopathy.