Equis ISSN 2398-2977

Optic nerve: neuritis

Contributor(s): Dennis E Brooks, Graham Munroe

Introduction

  • Inflammation of the optic nerve.
  • Incidence: rare condition; accompanies a number of systemic disease, panuveitis or multifocal central nervous system (CNS) infections.
  • Signs: unilateral or bilateral lesions some of which may be subclinical, whilst others are obscured by uveitis pathology; severe optic neuritis   →   blindness, swelling and hyperemia of optic disk, grey/white exudation from edges of optic disk.
  • Treatment: directed at the primary disease problem and suppressing the inflammatory processes.
  • Prognosis: guarded to poor - common sequele are ischemic retinopathy and optic atrophy.

Pathogenesis

Etiology

  • Causes of panuveitis including chorioretinitis , leptospirosis ,Onchocerca cervicalislarvae , and immune-mediated cases.
  • Septic lesions of the optic nerve +/- septic uveitis +/- panophthalmitis eg septicemia in foals/adults , septic endocarditis , multifocal protozoan encephalomyelitis includingToxoplasma gondiiandSarcocystis neurona.
  • Bacterial; organisms including:Streptococcusspp   Streptococcus spp  especiallyStreptococcus equi,Rhodococcus equi  Rhodococcus equi  ,Borrelia burgdorferi(Lyme Disease)   Borrelia burgdorferi  ,Actinobacillus equuli.
  • Other causes are rare: include: Togaviral encephalomyelitis, Borna Disease , Equine Herpes Virus I (EHV1)   Abortion: EHV-1  , EHV4   Equine herpesvirus  .

Pathophysiology

  • Inflammation of the optic nerve.
  • A rare condition that accompanies a number of systemic diseases, uveitis /chorioretinitis and multifocal CNS infections.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Rebhun W C (1992) Retinal and optic nerve diseasesVet Clin N A Equine Pract (3), 587-608 PubMed.
  • Matthews A G, Crispin S M and Parker J (1990) The equine fundus III - Pathologic variants. Equine Vet J 10, 55-61 Wiley Online Library.
  • Crispin S M, Matthews A G & Parker J (1990) The equine fundus I - Examination, embryology, structure and function. Equine Vet J 10, 42-49 PubMed.

Other sources of information

  • Brooks D E (1999) Equine Ophthalmology. In: Veterinary Ophthalmology. Ed: Gelatt K N. 3rd edn. 1053-1116.


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