Purpose
To demonstrate an updated design of a cost effective, portable, and user-friendly contact fundus imaging system for use with small animals.
Methods
An updated version of a compact, contact fundus imaging system based on previously published work (Hernandez et al, Vet Ophthal, 2011) was designed and constructed using a machine vision camera, an otoscope, a handheld rechargeable LED light source, standard optical lenses, and lens mounts. The use of a machine vision camera requires attachment to a laptop or PC via a USB cable. Digital fundus video and photography of a New Zealand white rabbit were obtained at BPEI. The pupils were dilated and a local anesthetic (proparacaine hydrochloride 0.5%, Alcon Inc., Fort Worth, TX) was applied. A gel (Gonak, Akorn Lake Forest, IL) was used to create a uniform interface between the tip of the otoscope and the cornea. Video was taken at 30 fps and still images were exported from the video file.
Results
No corneal epithelial damage occurred to the animal. Digital video and images of the fundus were obtained with a minimal learning curve required of the operator. Contrast of retinal vasculature and overall image quality were deemed acceptable for evaluating topical fundus morphology. Light intensity was adjusted via the portable LED light source and gain settings of the camera to reduce the saturation of the images. There was no specular reflex apparent in the images. The upgraded optical system produces images of similar quality and size as those obtained with the previous iteration of the fundus camera.
Conclusions
The upgraded portable, cost-effective contact fundus imaging system is easy to use for examination of the rabbit fundus, and is capable of acquiring video at up to 30 fps.
Keywords: 551 imaging/image analysis: non-clinical •
688 retina