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Basics ⬇

Outline

BASICS

Overview!!navigator!!

Atrophy of the optic nerve due to inflammatory or noninflammatory causes. In the early stages, the ophthalmoscopic appearance of the optic nerve head may be normal although the eye is blind. With time, the optic disc becomes pale with profound vascular attenuation and an obvious granularity of the optic disc due to exposure of the scleral lamina cribrosa.

Systems Affected

Ophthalmic

Signalment!!navigator!!

N/A

Signs!!navigator!!

Common signs regardless of the cause:

  • Blindness and pupil dilatation of the affected eye
  • Optic nerve pallor
  • Visualization of the lamina cribrosa
  • Peripapillary vascular attenuation

Causes and Risk Factors!!navigator!!

  • Inflammatory—optic neuritis, equine recurrent uveitis, chorioretinitis, sphenopalatine sinusitis
  • Noninflammatory—trauma to head and orbit, glaucoma, toxins, pituitary neoplasia, retrobulbar neoplasia, compression, acute blood loss

Diagnosis ⬆ ⬇

Outline

DIAGNOSIS

Differential Diagnosis!!navigator!!

  • Optic nerve hypoplasia
  • Orbital trauma
  • Retinal detachment
  • Glaucoma
  • Cataract

CBC/Biochemistry/Urinalysis!!navigator!!

N/A

Other Laboratory Tests!!navigator!!

N/A

Imaging!!navigator!!

Ocular ultrasonography, MRI, or CT scan may be of value in cases of head trauma, neoplasia, and sinusitis.

Other Diagnostic Procedures!!navigator!!

Electroretinogram

Treatment ⬆ ⬇

TREATMENT

There is no therapy for this condition; however, treatment of the underlying cause is recommended, if possible.

Medications ⬆ ⬇

MEDICATIONS

N/A

Follow-up ⬆ ⬇

FOLLOW-UP

Expected Course and Prognosis

Poor prognosis for vision.

Miscellaneous ⬆ ⬇

Outline

MISCELLANEOUS

Associated Conditions!!navigator!!

See Causes and Risk Factors.

Abbreviations!!navigator!!

  • CT = computed tomography
  • MRI = magnetic resonance imaging

Suggested Reading ⬆ ⬇

Brooks DE. Retinopathies and ocular manifestations of systemic diseases in the horse. In:Brooks DE, ed. Ophthalmology for the Equine Practitioner, 2e. Jackson, WY: Teton NewMedia, 2008:207–225.

Gilger BC. Equine ophthalmology. In: Gelatt KN, Gilger BC, Kern TJ, eds. Veterinary Ophthalmology, 5e. Ames, IA: Wiley Blackwell, 2013:1560–1609.

Nell B, Walde I. Posterior segment diseases. Equine Vet J Suppl 2010;37:69–79.

Wilkie DA. Diseases of the ocular posterior segment. In: Gilger BC, ed. Equine Ophthalmology, 2e. Maryland Heights, MO: Elsevier Saunders, 2011:367–396.

Author(s) ⬆

Author: Bianca C. Martins

Consulting Editor: Caryn E. Plummer

Acknowledgment: The author and editor acknowledge the prior contribution of Maria Källberg and Dennis E. Brooks.