angioscotoma

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angioscotoma

 [an″je-o-sko-to´mah]
a defect in the visual field caused by the shadow of the retinal blood vessels.

an·gi·o·sco·to·ma

(an'jē-ō-skō-tō'mă),
Ribbon-shaped defect of the visual fields caused by the retinal vessels overlying photoreceptors.
[angio- + G. skotōma, dizziness, vertigo]

angioscotoma

/an·gio·sco·to·ma/ (an″je-o-sko-to´mah) a centrocecal scotoma caused by shadows of the retinal blood vessels.

an·gi·o·sco·to·ma

(an'jē-ō-skō-tō'mă)
Ribbon-shaped defect of the visual fields caused by the retinal vessels overlying photoreceptors.
[angio- + G. skotōma, dizziness, vertigo]

angioscotoma 

A scotoma produced by the shadow cast by the retinal blood vessels. It looks like the branches of a tree extending from the blind spot. It is seen only in special conditions of illumination as when illuminating the fundus of the eye by gently moving a penlight over the closed eyelid, or when illuminating the fundus through the sclera, or when plotting the visual field. This phenomenon is sometimes used as a test to predict gross macular function in a patient with dense cataract where visualization of the fundus is impossible, although better results are obtained with the blue field entoptoscope. Syn. Purkinje figures; Purkinje shadows; Purkinje tree. See entoptic image.