Diffuse unilateral subacute neuroretinitis
| Diffuse unilateral subacute neuroretinitis | |
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| Other names: Unilateral wipe-out syndrome[1] | |
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| Left eye retina photograph shows moving nematode larva at the macular area [2] | |
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| Specialty | Ophthalmology |
Diffuse unilateral subacute neuroretinitis (DUSN) is a rare condition that occurs in otherwise healthy, often young patients and is due to the presence of a subretinal nematode.[3]
Signs and symptoms
The clinical findings in this disease can be divided into acute and end-stage manifestations:
In the acute phase, patients often present with decreased visual acuity, vitritis, papillitis, and crops of gray-white or yellow-white outer retinal lesions. The clustering of the retinal lesions is important because this often helps to localize the causative nematode.
If left untreated, patients ultimately develop late sequel, which may include optic atrophy, retinal arterial narrowing, diffuse retinal pigment epithelial changes, and an abnormal electroretinogram. The late findings of this condition are often misinterpreted as unilateral retinitis pigmentosa.
Cause
DUSN may be caused by a helminthic infection with Toxocara canis, Baylisascaris procyonis, or Ancylostoma caninum. The characteristic lesions are believed to result from a single nematode migrating within the subretinal space. Although previously thought to be endemic in some areas, that belief was likely due to under awareness. DUSN has been diagnosed in patients in many countries and climates including America, Brazil, China and India.[2]
Diagnosis
As to the diagnosis of DUSN relies on clinical suspicion, visualization of a subretinal nematode, and exclusion of other causes of unilateral retinal degeneration.During a fundus examination, if the nematode is visible, it is usually located in the macula near yellow-gray-white retinochoroidal lesions[4]
Treatment
If the nematode can be seen by an ophthalmologist, which occurs in less than half of cases, it should be treated with photocoagulation for extramacular location and surgical removal in case the larva is lying in the macula. After the worm is killed, visual acuity loss usually does not progress. Alternatively, Antihelminthic treatment such as high dose oral Albendazole and prednisolone may be used.[2]
References
- ↑ "Diffuse unilateral subacute neuroretinitis (Concept Id: C0339404) - MedGen - NCBI". www.ncbi.nlm.nih.gov. Retrieved 4 October 2025.
- ↑ 2.0 2.1 2.2 Yusoff, M; Alwi, AA; Said, MM; Zakariah, S; Ghani, ZA; Zunaina, E (Jun 16, 2011). "Intraocular nematode with diffuse unilateral subacute neuroretinitis: case report". BMC Ophthalmology. 11: 15. doi:10.1186/1471-2415-11-15. PMC 3127854. PMID 21679403.
- ↑ American Academy of Ophthalmology (2012). Retina and vitreous (2011-2012 ed.). American Academy of Ophthalmology. ISBN 9781615251193.
- ↑ "Diffuse Unilateral Subacute Neuroretinitis (DUSN) - EyeWiki". eyewiki.org. Archived from the original on 9 May 2025. Retrieved 4 October 2025.
External links
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