Contributor: Eric Chin, MD
Photographer: Toni Venckus, CRA
“Many black spots”
20-year-old male, otherwise healthy, presenting for routine follow-up. Black spots were seen incidentally on review of fundus photographs for eye disease in the contralateral eye.
Vision OS: 20/20 cc
Spectacle Rx: -4.00 sphere OU
(click on Figure links below to see higher resolution images)
Figure 1: OS: clear media, normal nerve, normal vessels, normal macula; multiple faint ill-defined black spots are seen in the mid-periphery
Figure 2: Black spots are highlighted with red circles.
Figure 3: Dashed red lines show the collection of fundus photos pieced together to form the wide-field montage
Figure 4: Black spots are not coincidentally seen at the center of each photo, confirming the presumption of Allen dots.
Some auxiliary lenses used with fundus photography cameras can cause “Allen Dots” which are faint artifactual darkened round spots at the center of a fundus image. They may be seen with single images, or with montage images as this case demonstrates.
Allen dots are more commonly seen with myopes. They can potentially obscure detail in areas of interest (e.g. the fovea center). Slightly adjusting the patient’s fixation to de-center the Allen dot in less critical area is a potential solution.
Seeing the dark spot (i.e. Allen dot) at the center of each (and sometimes every) photograph confirms that this is only an artifact. Also, they will not be seen with clinical exam (i.e. slit lamp biomicroscopy and indirect ophthalmoscopy).
Ophthalmic Atlas Images by EyeRounds.org, The University of Iowa are licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.