Download - 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).