Purpose:
The prevalence of Diabetic Retinopathy (DR) has been growing at a dramatic rate and is the leading cause of new cases of blindness in patients 20-74 years of age in the U.S. The extra cost and inconvenience of seeing an eye specialist causes many patients to be non-compliant with recommended yearly dilated screening exams. The proposed diagnostic camera aims to circumvent these problems by providing low cost retinal photographic screening within the primary care physician’s clinic that is easy to use with minimal training.
Methods:
The fundus camera design consists of a novel optical attachment integrated with a Canon consumer digital camera (Canon G11). Illumination of the retina is achieved through the use of LEDs and Xenon flash via fiber optic cable coupling along with a combination of beam-splitters and additional optics to produce standard ring illumination at the corneal surface. A front mounted 22D ophthalmologic lens directs illumination into the eye and transmits the fundus image to the camera, providing a standard 60 degree field of view. Images are then captured and stored on the camera’s SD memory card.
Results:
By taking advantage of recent improvements in the consumer digital camera industry, such as image stabilization and LiveView, the proposed device succeeded in being compact while maintaining the user friendliness of a common point-and-shoot digital camera. The device is low cost ($<1000 in parts), is able to be used by untrained medical personnel, is hand-held with no external power supply, and is capable of taking superior quality images of the fundus (Fig. 1).
Conclusions:
The current prototype fundus camera produces images of sufficient quality for screening purposes. When coupled with an automated off-site image review service for the primary care provider, we believe this device can have a substantial impact on providing appropriate eye care for diabetics within the US. It may also find use for low cost fundus photography in developing nations.Figure 1: (A) Typical fundus image from current camera prototype (B) Prototype camera consisting of Canon G11 camera with novel lens attachment and fiber optic coupled flash.
Keywords: imaging/image analysis: clinical • diabetic retinopathy