Abstract
Abstract: :
Purpose: To develop a novel, low–cost, portable, non–commercial, digital camera system for posterior segment photography in situations where professional ophthalmic photography is unavailable or impractical. Methods: We have designed a mydriatic non–contact fundus camera using a standard Nikon 4300 digital camera with a custom lens attachment. This attachment contains 1) an inexpensive three stage optic design to provide image magnification and reduce the working distance of the camera, 2) a ring of bright white LEDs with fresnel lens and a novel light coupling system to provide even fundus illumination while minimizing light reflection, and 3) a standard mount for a readily available 78 or 90 diopter lens as part of the optical design to reduce overall system cost. Focus, shutter speed, and aperture settings were preset, with minimal subsequent user intervention required. Results: We obtained excellent posterior segment photographs using this modified consumer digital camera. The novel optical and illumination design allows the camera to provide an evenly illuminated field of view that contains retinal details of excellent quality to allow for documentation and screening of posterior segment conditions. We show that this fundus camera can be constructed for less than $500 and can be used by most ophthalmologists with minimal photographic skill to document ophthalmic findings. We show that the photographic quality of this system is in many cases comparable to that obtained with more expensive alternatives. Conclusions: We have demonstrated how a commercially available, consumer, digital camera can be modified relatively easily and inexpensively for fundus photography. This was accomplished with a novel optical lens and illumination design that provides even illumination of the fundus. While this design is not intended to replace commercial photographic systems, we feel that it is viable alternative in situations where conventional ophthalmic photography is not available. It may also provide a means to screen for retinal diseases when access to commercial alternatives is not available.
Keywords: imaging/image analysis: clinical • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina