optic neuritis

• Optic neuritis is an inflammation of the optic nerve

of either one or both eyes,, it either: i. papillitis: if it restricted to the optic nerve head.ii. Retrobulbar: if the inflammation in the back of the eye.

• Usually unilateral • typically affecting young adults 18 – 45 yrs• More common in female• Incidence 1-5 per 100,000 per year

A. Idiopathic or May be due to :

B. Autoimmune disorder : the immune system attack the myelin sheath of the optic nerve, which become swolled & inflamed, like what happen in :

i. Multiple sclerosis

ii. Neuromyelitis optica

C. Infections :

i. Bacterial

ii. Viral

Changes in white matter in Multiple sclerosis

D. Ischemic : the optic nerve is infarcted due to occlusion or decrease perfusion of posterior ciliary vessels, it either:

Non artretic: diabetes, hypertension, atherosclerosis.

Arteritic: temporal arteriris which is an inflammation of the lining of the arteries within the skull.

E. Toxins : exogenous , endogenous

F. Some drugs e.g. ethambutol

G. Leber's hereditary optic neuropathy

H. Radiotherapy to the head

Temporal arteritis

Anterior ischemic neuropathy

TypesTypes

Acute Acute Chronic Chronic

Papillitis Papillitis retrobulbarretrobulbarAlcohol

ambylopiaAlcohol

ambylopia

Tobacco ambylopia

Tobacco ambylopia

• Sudden visual loss

• Impaired color vision varry from blurring up to complete blindness.

• Impaired contrast sensetivity

Patient see objects as it washed out or cloud infront.

Also complain of spots, sparkles & loud noise.

• Pain in case of retrobulbar

• neuritis worsened by eye movement.

In papillitis optic disk swelling

In retrobulbar –< no abnormal changes

In ischemic neuropathy

-> pale swolled disc

Visual acuity

test

Contrast sensetivity

test

Visual acuity is markedly reduced up to no perception of light

Color vision test : impaired

Pupillary light reaction test : RAPD

The pupil of the affected eye don’t

react to direct light

but react to the indirect

Visual field test : central scotomaVisual field test : central scotoma

MRI MRI

To diagnose multiple sclerosis -> abnormalities in white matter

• It usually resolve spontaneously but treating with steroids speed up vision recovery.

Treatment of underlying causes( infections, immune disorder, .. ) life style modification in diabetic & hypertensive patientsEarly treatment of vision proplems

Optic nerve damageDecrease visual acuity Side effects of steroids: immunosuppresion, Osteoporesis

•Most cases resolve spontaneously with return of vision in two weeks to three months •Some cases show recurrence

•Toxic reaction in optic nerve•Bilateral• symmetrical•Retrobulbar

•Painless visual loss •Decrease color vision

•Toxins ( tobacco , Lead, methanol, chloramphenicol, quinine) cause damage to optic nerve & ganglion cells, aggravated by malnutrition, defecincies of protein, vitamin B12, antioxidant)

•History of : - exposure to toxins - malnutrition

•Visual field : paracentral scotoma

•Fundus : early no changes , late become pale

•Healthy life style•Stop exposure to toxic substances•Oral or parenteral vitamin B

Vision may improve if the cause is treated or removed quickly.

•There are no scientifically validated preventive measures for optic neuritis. Anecdotal evidence suggests that maintaining a healthy lifestyle with proper attention to good nutrition, exercise, prevention of obesity, maintenance of emotional health and adequate rest, together with avoidance of toxins such as cigarettes, may prevent many diseases. Regular annual eye exams are critical to maintaining healthy vision.• Early treatment of vision problems can prevent permanent optic nerve damage (atrophy).