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Ophthalmology and Visual Sciences

Diffuse Unilateral Subacute Neuroretinitis (DUSN)

Diffuse Unilateral Subacute Neuroretinitis (DUSN)

Category(ies): Retina, Vitreous
Contributor: David Phillips, MD

This 45-year-old male presented with blurry vision in his left eye and was referred to the University of Iowa for unilateral uveitis. A subretinal nematode was identified on exam next to a crop of yellow-white macular lesions. He was diagnosed with diffuse unilateral subacute neuroretinitis (DUSN), likely secondary to raccoon roundworm (Baylisascaris procyonis) as the patient was an avid outdoorsman and hunter. The nematode was killed by laser and the patient completed albendazole 400mg/day for 30 days. Included are photos demonstrating the nematode in two different locations and after laser treatment.

fundus showing nematode in macula
Figure 1: Nematode in the macula and macular inflammation
Enlarged fundus showing nematode in macula
Figure 1b: Enlarge Nematode in the macula and macular inflammation
fundus showing nematode in periphery
Figure 2: Nematode in the periphery before laser
fundus showing scar after macular scar
Figure 3: Macular scar from previous inflammation and peripheral laser from killed nematode