eMedicine Specialties > Ophthalmology > Retina

Neuroretinitis, Diffuse Unilateral Subacute: Treatment & Medication

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

Updated: May 26, 2009

Treatment

Medical Care

  • Laser photocoagulation of the nematode is the treatment of choice. Direct laser photocoagulation has been effective in destroying the worm. In early stages of DUSN, prompt localization and destruction of the worm by photocoagulation may improve the vision of patients, and, in other situations, the progression of the disease is halted. No significant intraocular inflammation has been associated with this treatment.
  • Antihelminthic treatment is being used more frequently. It may be considered when the organism cannot be found.

Surgical Care

  • Although direct laser photocoagulation of the nematode is the treatment of choice for DUSN, surgical transvitreal removal of the nematode may be indicated in selected cases.
    • Pars plana vitrectomy and removal of an intact parasite by various vitrectomy instrumentation allow removal of the nematode for parasitologic identification.
    • In addition, the inflammation may completely subside with recovery of function.

Consultations

Consultation with a uveitis or retinal specialist is often useful for patients with suspected DUSN.

Medication

Antihelminthic treatment is for patients with moderate-to-severe vitreous inflammation or when it is not possible to locate and treat the nematode with photocoagulation. However, it is not effective in destroying the organism in all patients, especially in those with minimal vitreous inflammation where the drug has low ocular penetration.

Thiabendazole is the drug of choice for initial medical therapy. Successful treatment is characterized by the development of a localized area of intense retinitis and fading of the grayish-white retinal lesions within 10 days after completion of therapy.

Ivermectin may be considered if thiabendazole is not effective or cannot be tolerated.

High-dose oral albendazole seems to be safe and beneficial for patients with active DUSN in the early or late clinical stage.

Anthelmintics

Vermicidal drugs that kill the organism by various antihelminthic actions.


Thiabendazole (Mintezol)

An antihelminthic agent. Probably acts by inhibiting the helminth-specific enzyme fumarate reductase. Vermicidal and/or vermifugal.

Adult

22 mg/kg PO bid for 2-4 successive d in patients with moderate-to-severe vitritis; not to exceed 3 g/d
More recently, 25 mg/kg/d PO qhs for 25 d has been recommended

Pediatric

Administer as in adults; in pediatric patients <30 lb, safety and effectiveness is limited

When used concomitantly with xanthine derivatives, it may be necessary to monitor the blood levels and/or reduce the dosage of such compounds

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Frequent adverse effects include nausea, vomiting, anorexia, and mild central nervous system disturbances such as dizziness, drowsiness, or headache


Ivermectin (Stromectol)

A semisynthetic, anthelmintic agent mainly used for filarial worms. Effectiveness in the treatment of DUSN is unclear.

Adult

150 µg/kg PO once

Pediatric

Administer as in adults; not established in pediatric patients <15 kg

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Frequent adverse effects include nausea, vomiting, anorexia, and mild central nervous system disturbances


Albendazole (Albenza)

A benzimidazole carbamate drug that inhibits tubulin polymerization, resulting in degeneration of cytoplasmic microtubules. Decreases ATP production in the worm, causing energy depletion, immobilization, and finally death. Converted in the liver to its primary metabolite, albendazole sulfoxide. Less than 1% of the primary metabolite is excreted in the urine. Plasma level is noted to rise significantly (as much as 5-fold) when ingested after high-fat meal. Experience with patients <6 y is limited. To avoid inflammatory response in CNS, patient must also be started on anticonvulsants and high-dose glucocorticoids.

Adult

400 mg PO qd for 30 d has been used

Pediatric

<15 kg: Not established
>15 kg: Administer as in adults

Coadministration with carbamazepine may decrease efficacy; dexamethasone, cimetidine, and praziquantel may increase toxicity

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Discontinue use if LFTs increase significantly (resume when levels decrease to pretest values); abdominal pain, nausea, vomiting, diarrhea, dizziness, vertigo, fever, increased intracranial pressure, and alopecia may occur

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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