Diagnosis Of Diffuse Unilateral Subacute Neuroretinitis Research Articles

Amblyopia or Pathology? Diffuse Unilateral Subacute Neuroretinitis in a Pediatric Patient

Background: Diffuse unilateral subacute neuroretinitis (DUSN) is a retinal disorder cause by a subretinal nematode. The disorder tends to affect children and young adults. It is characterized by unilateral retinal pigment epithelium changes, vitritis, retinal vessel narrowing and, in advanced stages, optic atrophy. Patients are generally asymptomatic or report a painless loss of vision. It has been described in the United States as well as Latin America, Asia and Europe. Case Report: A 9 year old female, recently adopted from the Ukraine, presented for an eye exam after failing a vision screening. Uncorrected visual acuity was 20/20 OD, 20/30 OS with hyperopia OS>OD. A dilated examination revealed pigment epithelial changes in the macula OS only. Examination by a retinal specialist included ocular coherence topography and a fluorescein angiography. Blood work and stool samples were normal. A diagnosis of DUSN was made and laser photocoagulation was performed around the suspected worm. The patient tolerated the procedure well. After treatment, and with her eyeglasses, visual acuity was 20/25 OS. Conclusion: Diffuse unilateral subacute neuroretinitis (DUSN) is a condition that can be detected on a routine exam in asymptomatic patients. Recognition of the condition and prompt treatment is important to help delay disease progression and preserve visual acuity.

Diffuse unilateral subacute neuroretinitis in the United Kingdom

We describe the first two cases of diffuse unilateral subacute neuroretinitis (DUSN) in the UK successfully treated with albendazole. Two patients are described who presented with unilateral reduction in vision, with clusters of yellow-white retinal lesions fading and reappearing in new locations of the fundus over a period of weeks. Based on the clinical picture, the diagnosis of DUSN was made, even though no subretinal worm could be found. Both patients were treated with albendazole 400 mg daily for 30 days. After 4 weeks the vision in the affected eye improved to 6/9 in each patient and the retinal lesions resolved completely. Over a follow-up period of 28 months and 13 months respectively, there was no recurrence of any lesion and the vision was maintained. DUSN is a sight-threatening disease and the preservation of vision relies on early diagnosis and treatment. Laser photocoagulation of the worm is the treatment of choice, but this was not possible in either case, as no worm could be found; however, oral albendazole proved to be a safe and effective alternative treatment.

538 Neurorétinite subaiguë unilatérale diffuse : à propos de 2 cas

Introduction Diffuse Unilateral Subacute Neuroretinitis (DUSN) is an ocular infectious disease caused by a motile nematode, leading to inflammation and degeneration of the outer retina. This affection has already been reported in literature from Brazil, Venezuela, USA, Canada, Caribbean, Spain, Germany, Ghana, India, and we describe here two cases from UK. Aim and Methods Two healthy women, frequent travellers, presented with unilateral reduction in vision respectively from 6/6 to 6/18 and from 6/6 to 6/24, with clusters of yellow-whitish sub-retinal pigment epithelial lesions fading and reappearing in other location of the fundus, after days to weeks. Based on the clinical picture the diagnosis of DUSN was established. After several unfruitful tentatives of localising the worm by slit lamp examination with a fundus lens, both patients were prescribed with an antihelminthic treatment, albendazole 400 mg daily for 30 days. Observation Improvements of the visual acuity to 6/6 as well as complete resolution of fundoscopic lesions were observed in both of them. The visual acuity was maintained and no new lesions were observed, respectively, over a period of follow up of 12 and 8 months. Visual field defects were unchanged. Discussion This condition can affect children or young adults, with no gender predilection or systemic association. The eye is affected in such an insidious manner, that in most of cases patients realize their visual loss only towards the late stage of the disease. The appearance followed by the disappearance of creamy lesions within days to weeks concomitantly with the development of new clusters of lesions elsewhere in the fundus, even without any worm seen, is highly suspicious of the diagnosis of DUSN. Therefore it is important to review the patient as often as needed when this condition is suspected. Even though laser photocoagulation of the worm is the best way to eradicate the problem, this is not always possible since the worm is found in 40% of the cases only. In such cases oral albendazole seems to be a safe and valuable treatment. Conclusion DUSN is a sight threatening disease. Preservation of the visual acuity relies on an early diagnosis and treatment.

Diffuse Unilateral Subacute Neuroretinitis: Morphometric, Serologic, and Epidemiologic Support for Baylisascaris as a Causative Agent

Several nematodes have been postulated as etiologic agents in diffuse unilateral subacute neuroretinitis (DUSN), but the cause of this condition remains uncertain. The authors report the first case of DUSN from the western United States (northern California), along with morphometric, serologic, and epidemiologic evidence supporting Baylisascaris procyonis as its cause.One patient was examined and evaluated for disc edema and transient obscurations of vision. A diagnosis of DUSN was confirmed when a motile nematode was identified within the substance of the patient's retina. Morphometric analysis of the nematode was done from projected fundus photographs. Serologic evidence of Baylisascaris infection was suggested by Western blot analysis. A necropsy was done on 12 raccoons from the area. They were examined for evidence of Baylisascaris infection, previously believed to be nonendemic in the region.The intraocular nematode measured 1727 x 67 microns, most consistent with Baylisascaris. The patient had considerable exposure to raccoons, and was seropositive for B. procyonis infection on Western blot analysis. Necropsy evaluation showed B. procyonis infection in 8 of 12 raccoons examined from the area.The morphometric, serologic, and epidemiologic findings in this case provide evidence that the raccoon ascarid, B. procyonis, is a cause of the large nematode variant of DUSN.