RETRO-BULBAR OPTIC NEURITIS.
Definition. Neurites descendens and ascendens. Extension to bulb, other eye, or brain. Causes: traumas, meningitis, infectious diseases, toxins, lead, tobacco, etc. Symptoms: partial blindness: congestion of papilla, exudates in adjacent retina. Treatment: eliminate poisons, lead, toxins, correct precedent disease, saline laxatives, diuretics, potassium iodide, cupping, local bleeding, counter-irritants. Hygiene.
This is inflammation of the optic nerve commencing behind the eyeball and only involving the papilla secondarily. Extension to the papilla has been called neuritis descendens in contradistinction to neuritis ascendens in which the inflammation extends along the nerve toward the brain. There is always a tendency to extension, it may be to the papilla and retina, it may be to the chiasma and opposite eye, and it may be inward toward the ganglia and choroid plexus.
Causes. Apart from traumatic causes, retro-bulbar neuritis in the domestic animals has been mainly seen in connection with constitutional or infectious diseases; in the horse with petechial fever (Peters), contagious pneumonia (Schindelka), meningitis (Peters, Straub) and parotitis (Möller). It has also followed meningitis in cattle (Nebelen). In man it has been traced to lead, tobacco, alcohol and other poisons.
Symptoms. At first the patient may seem partially blind without apparent cause. Later ophthalmoscopic examination reveals congestion and swelling of the papilla, and congestion (especially venous and capillary) of the retinal vessels. The discolorations in streaks and spots, from exudates and degenerations follow as noticed under papillitis. It is difficult to distinguish between this and papillitis during life.
Treatment should be first directed toward the elimination of any poisons, such as lead or tobacco, which may act as a causative factor. Saline laxatives and in chronic cases potassium iodide would be indicated. Every attention should be given to the maintenance of good general health, and in acute attacks, local bleeding and counter-irritation may be resorted to.