DISEASES OF THE OPTIC NERVE

Budu, M.D, Ph.D

DEPARTMENT OF OPHTHALMOLOGY,FACULTY OF MEDICINE, HASANUDDIN UNIVERSITY

MAKASSAR2003

Diseases of the optic nerve : …….

1. Optic neuritis

2. Papiledema

3. Optic atrrophy

4. ……

Optic Neuritis

Optic neuritis (ON) is inflammation of the optic nerve.

ON may be divisible into 2 types :

1. Intra ocular optic neuritis (papillitis)

2. Retrobulbar optic neuritis

Etiology :

1. Local inflammatory conditions : - retinitis - Symphatetic ophthalmia - meningitis - Sinus or orbital inflammation 2. General Inflammation conditions - demyelinating diseases - syphilis - tuberculosis3. Leber`s Diseases 4. Endogenous toxin, - acute infective fever (influenza, measeles, mumps) - septic foci (tonsilitis, sinusistis) - metabolic diseases ( DM, avitaminosis, anemia)5. Exogenous toxins, such tobacco, ethyl alkohol, arsenic, quinine, etc.

Papillitis

It is inflammation of the optic nerve head (intraocular part of the optic nerve.)

Clinical features :

Symptoms,-Unilateral with suddenly loss of central vision-There are may be some pain in behind of eyeball

Sign,-Optic disc hyperemic with blurred margins-On the progressed conditions, swelling and edema of the disc and surrounding retina-Retinal veins are engorged and soft exudate of the disc.-Flame shaped haemorhages around the disc.-Fine floating opacities of the posterior vitreous humour-Relative central scotoma

Differential diagnosis : papilloedema (next)

Treatment :

Should be directed to remove the underlying cause.

-Rest to the eye, and protection from light.-Neurotropic, such as Vit. B complex-Systemic antibiotic-Costicosteroid

Retro-Bulbar NeuritisIt is inflammation of the retro-bulbar portion of optic nerve. Retrobulbar neuritis can be divided into 2 parts : acute and chronic retrobulbar neuritis,

Acute retrobulbar neuritis

It is acute type of neuritis characterized by profound loss of sight with no ophthalmoscopic findings in the fundus.

The patient sees nothing and the doctor sees nothing !!!!

Clinical features :

Symptoms,-Sudden and profound loss of central vision-There are may be some pain with the movement of the globe-Headache as the same side of the lesion

Sign,-The eye appear normal externally-Fundus examination reveals no obvious changes. -Scotometry reveals central or centro-caecal scotoma.

CourseIn most cases, there is spontaneous recovery and recurrences are not uncommon.

TreatmentSame as papillitis

Papilloedema

It is a passive, non inflammatory edema of the optic disc due mostlyto raised intracranial pressure. Most of cases are bilateral.

Etiology :

a. Rise of intra cranial pressure due to any space-occupying lesion of the cranium, such as brain tumor, cerebral abscess, brain haematomab. Local orbital causes ….. Unilateral papilloedemac. Certain general diseases, such as malignant hipertention, nephritis, leukemia.

Clinical features :

Symptoms, are often negligible

- Transient blurring of sight lasting from 5-20 seconds- Normal visual acuity for several months, but failure of sight with associated with secondary optic atrophy.

Sign,-Hyperemic optic disc with retinal vein engorgement at initial stage-At progressive conditions, blurred of the disc margin appear.-In the later stage, swelling of optic disc, 2-8i dioptres-Flamed shape haemorrhages and soft exudate around the disc.-Exudate of the macula ----- macular star.-Field changes : blind spot (earlier), central scotoma (macular involvement), concentric visual field (optic atrophy)

CourseA short period of oedema ---- little or no permanent change.Several weeks or month durations ------ secondary optic atrophy ---- blindness

Differential diagnosis : papillitis

Papillitis

-Disc swellings 2 D-Venous engorgmenet and retinal haemorrhages +++-Loss of sight sudden and profound-Transient and recovery 1-2 weeks-Field defect central scotoma for red and green color

Papilloedema

-Disc swelling 6D-Venous engorgmenet and retinal haemorrhages+-Visual loss negligible and gradual - Blindness in untreated patients-Field defect concentric contractrion of the peripheral field

TreatmentRemove the underlying causes (intracranial)-Tumor– remove with surgical intervention-Abcess- drainage