Contributor: Kevin R. Kazacos
DUSN (diffuse unilateral subacute neuroretinitis, diffuse unilateral subacute neuroretinopathy) is a syndrome characterized by an insidious unilateral widespread destruction of the sensory retina associated with inflammation. The neuroretinitis was first defined by Gass and Scelfo in 1978 and is caused by the larvae of several nematodes [nematode disease], but most cases seem to be due to Baylisascaris [baylisascariasis], Toxocara canis [toxocariasis], hookworms [hookworm infestation], and Strongyloides [strongyloidiasis]. The condition usually results in a sudden loss of vision and this is followed by the gradual loss of sufficient retina to cause an afferent pupillary defect and ERG abnormalities. A difffuse or focal derrangement of the retinal pigment epithelium occurs, but this spares the macula. Other features include optic atrophy and a narrowing of the retinal blood vessels.

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