250-PLUS SHADES OF GRAY

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Images from the CR-2 PLUS AF Digital Retinal Camera from Canon offer great detail, even
when enlarged.
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This FAF image demonstrates both
hypo- and hyperfluorescence.

Canon’s CR-2 PLUS AF non-mydriatic retinal camera delivers high contrast images from undilated fundus photos.

Retinal cameras have become the standard of care in most eyecare practices to document the posterior segment. The Canon CR-2 PLUS AF is a compact non-mydriatic retinal camera with auto-focus, auto-capture, and auto-exposure, producing 45° high resolution 20 megapixel images of the retina. One of its most valuable diagnostic features is fundus auto-fluorescence (FAF) photography. Retinal images can be captured in full color or processed as digital red-free, digital cobalt, or with a unique emboss effect.

FAF IMAGES
The FAF photography mode allows the clinician to detect subtle changes that can indicate disease earlier. Lipofuscin, a fluorescent pigment, accumulates in the retinal pigment epithelial (RPE) layer as a metabolic byproduct of cell function.

An FAF image is captured by passing a low intensity flash through an exciter filter causing lipofuscin in the RPE to auto-fluoresce. The reflected light exits the eye and passes through a barrier filter that passes the wavelength specific to lipofuscin. Images are monochromatic with 256 shades of gray.

Understanding the distribution pattern of lipofuscin in the normal retina is key to interpreting an FAF image and diagnosing pathology. The posterior pole of a healthy patient will have an overall diffuse appearance. In general, the optic nerve, blood vessels, and the fovea will appear dark. The posterior pole of a patient with a retinal pathology will show abnormal areas as hypofluorescent (darker) or hyperfluorescent (lighter) appearance. The detailed posterior segment images can be used for patient education and provide the opportunity to document changes in pathology.

The Canon CR-2 PLUS AF provides an important non-invasive technology to assist in diagnosing retinal pathology not possible with full color imaging.

Ken Lebow, OD, FAAO, is in private practice in Virginia Beach, VA, and is on the Optometric Office editorial advisory board.

WHERE TO FIND IT:
Canon
800.970.7227 | usa.canon.com/eye-care

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