eMedicine Specialties > Ophthalmology > Retina

Neuroretinitis, Diffuse Unilateral Subacute: Differential Diagnoses & Workup

Author: Lakshmana M Kooragayala, MD, Vitreo-retinal Surgeon, Marietta Eye Clinic
Contributor Information and Disclosures

Updated: May 26, 2009

Differential Diagnoses

Papilledema
Presumed Ocular Histoplasmosis Syndrome
Sarcoidosis
Toxoplasmosis
White Dot Syndromes

Other Problems to Be Considered

Early stage

Active retinal lesions include the following:

Toxoplasmosis
Cytomegalovirus retinitis
Fungal or bacterial retinal abscesses
Acute posterior multifocal placoid pigment epitheliopathy
Multiple evanescent white dot syndrome
Serpiginous choroiditis
Behçet disease
Pseudo–presumed ocular histoplasmosis syndrome
Multifocal choroiditis

Perivasculitis includes sarcoidosis

Optic disc swelling includes acute neuroretinitis and papilledema

Vitritis includes pars planitis

Late stage

Retinal pigment epithelial atrophy includes the following:

Presumed ocular histoplasmosis syndrome
Unilateral retinitis pigmentosa
Traumatic chorioretinopathy
Chorioretinal atrophy after ophthalmic artery occlusion

Optic atrophy includes the following:

Secondary to optic neuritis
Compressive lesions
Ischemic optic neuropathy

Workup

Laboratory Studies

  • Serologic studies for parasites, analysis of stool for ova and parasites, and hematologic evaluation for eosinophilia are of limited value in establishing the diagnosis of DUSN.
  • Some serological tests may be indicated to exclude other diseases.

Imaging Studies

  • Fluorescein angiography is useful for monitoring the status of the inflammation.
    • Early stage of the disease
      • Leakage from the optic nerve head capillaries and some generalized paravenous leakage
      • Window defects indicating minimal changes in the RPE
      • Staining of the clinically apparent gray-white lesions during the later phases of the angiogram, which are nonfluorescent in the early phase
      • Cystoid macular edema in some patients
    • Late stages of the syndrome
      • Diffuse areas of focal hyperfluorescence secondary to RPE loss
      • Leakage from choroidal neovascularization
  • Scanning laser ophthalmoscope
    • Although an examination with a fundus contact lens by a skilled ophthalmologist is the method of choice, the scanning laser ophthalmoscope (SLO) provides a new examination modality with distinct advantages for identifying live worms in young patients with DUSN. The infrared laser is safe and comfortable for a prolonged examination.
    • Using blue illumination, the ocular fundus appears dark and provides a high-contrast background for the white image of the worm. The red perimetry laser stimulus can be used to stimulate the worm's movement and to pinpoint its location.

Other Tests

  • An electroretinogram (ERG) is used to objectively evaluate the functional status of the retina and to differentiate from other retinal conditions.
    • In the affected eye, the ERG usually is reduced in all stages of the disease.
    • It is often moderately or severely reduced in the later stages of the disease.
    • The b-wave is affected more than the a-wave.
    • Rarely, the ERG may be extinguished completely.
    • ERG findings are normal in the unaffected eye.
    • ERG performed before and after laser photocoagulation appears to be useful in monitoring the retinal findings. After laser photocoagulation, recovery of ERG findings may be documented.
  • Electro-oculogram (EOG) findings are abnormal in approximately 50% of patients.
  • Visual field
    • Paracentral and central visual field defects
    • Useful to monitor the visual field over a period of time and to differentiate from other conditions

Histologic Findings

The only histologic findings are from an enucleated eye presumed to have DUSN. Histopathology showed nongranulomatous vitritis, retinitis, and retinal and optic nerve perivasculitis. RPE and low-grade, patchy nongranulomatous choroiditis were observed. There was no evidence of a worm.

More on Neuroretinitis, Diffuse Unilateral Subacute

Overview: Neuroretinitis, Diffuse Unilateral Subacute
Differential Diagnoses & Workup: Neuroretinitis, Diffuse Unilateral Subacute
Treatment & Medication: Neuroretinitis, Diffuse Unilateral Subacute
Follow-up: Neuroretinitis, Diffuse Unilateral Subacute
References
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References

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Further Reading

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Keywords

diffuse unilateral subacute neuroretinitis, DUSN, diffuse bilateral subacute neuroretinitis, unilateral wipeout syndrome

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Contributor Information and Disclosures

Author

Lakshmana M Kooragayala, MD, Vitreo-retinal Surgeon, Marietta Eye Clinic
Lakshmana M Kooragayala, MD is a member of the following medical societies: American Academy of Ophthalmology, American Society of Retina Specialists, and Medical Association of Georgia
Disclosure: Nothing to disclose.

Medical Editor

Andrew A Dahl, MD, Director of Ophthalmology Teaching, Mid-Hudson Family Practice Institute, The Institute for Family Health; Assistant Professor of Surgery (Ophthalmology), New York College of Medicine
Andrew A Dahl, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Ophthalmology, American College of Surgeons, American Medical Association, American Society of Cataract and Refractive Surgery, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

R Christopher Walton, MD, Professor, Director of Uveitis and Ocular Inflammatory Disease Service, Department of Ophthalmology, Assistant Dean for Graduate Medical Education, University of Tennessee College of Medicine; Consulting Staff, Regional Medical Center, Memphis Veterans Affairs Medical Center, St Jude Children's Research Hospital
R Christopher Walton, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Healthcare Executives, American Uveitis Society, Association for Research in Vision and Ophthalmology, and Retina Society
Disclosure: Nothing to disclose.

CME Editor

Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri
Disclosure: Nothing to disclose.

Chief Editor

Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Hampton Roy Sr, MD is a member of the following medical societies: American Academy of Ophthalmology, American College of Surgeons, and Pan-American Association of Ophthalmology
Disclosure: Nothing to disclose.

 
 
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