Abstract
Purpose :
Non-mydriatic fundus cameras allow retinal photography without the use of drops to dilate the pupil. However, currently available non-mydriatic fundus cameras are bulky, not portable, and expensive. Taking advantage of recent advances in mobile technology, we sought to create a non-mydriatic fundus camera that was affordable, could fit in a white-coat pocket, and could be assembled from easily-available off-the-shelf components.
Methods :
We built a point-and-shoot prototype camera using a Raspberry Pi® single-boardcomputer, a NoIR camera board for the Raspberry Pi®, a 5 mm white light-emitting diode (LED), a 5 mm infrared LED, a battery, a 5-inch touchscreen liquid crystal display, and a 20 diopter condensing lens (see Figure 1). To use the camera, the photographer first dims the room lights to allow the patient’s pupils to naturally dilate. While holding the condensing lens in one hand and the camera in the other, he brings the fundus into focus with infrared light (see Figure 2A). Once the fundus is in focus, the photographer presses the shutter to flash the white LED and take a color photograph of the fundus (see Figure 2B) before the pupil has time to constrict.
Results :
The camera measured 14 cm x 8 cm x 5.5 cm and weighed 431 g. The total cost of the off-the-shelf components, including the disposable 20D lens, was $189. As seen in Figure 2B, the camera was able to obtain good-quality fundus images in eyes without pharmacologic dilation of the pupils, even in eyes with dark irides. The field of view was about six disc diameters. The camera was also found to meet international standards for infrared and white light eye safety.
Conclusions :
An inexpensive, hand-held, non-mydriatic fundus camera can be assembled from off-the-shelf components. This camera may be useful for a variety of healthcare professionals, particularly those who work in resource-poor areas or settings in which it is difficult to transport patients to a table-mounted camera, such as the inpatient setting.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.