Optic Neuritis Optic Atrophy Optic compressive neuropathies

Inflammation of the Optic Nerve An inflammation of the optic nerve is called OPTIC NEURITIS It is of two types Those affecting opthalmoscopically visible part of the disc Papillitis Neuroretinitis Those affecting nerve proximal to the disc and show no opthalmoscopic changes Retrobulbar neuritis

Aetiopathogenesis It is a demyelinating disorder with inflammatory response Most common cause is multiple sclerosis Others include Neuromyelitis optica Acute disseminated encephalomyelitis Epidemic encephalitis Polio myelitis Lebers disease

classification Idiopatic Demyelinating disorders Associated with infections Local systemic Immune mediated disorders Systemic Metabolic disorders

Clinical course Decreased vision Starts improvement in vision in 2nd or 3rd week Returns to near normal by 4th to 5th week Colour vision, contrast sensitivity & visual fields take longer to recover

Clinical features Visual loss over hrs to days and reaches a trough about 1 week after onset Deep orbital retro ocular or brow pain usually aggrevated by eye movement Neuralgia Headache Pulfrich’s phenomenon Uhthoff”s sign

Visual function depression is more marked in the central 20 degrees Marcus Gunn pupil :great diagnostic significance In case papillitis blurred margins with swelling and edema of the disc can be seen If post neuritic atrophy occur Margins blurred Floor has dirty grey coloured Organised tissue on arteries perivascular sheaths

Differential diagnosis Ischemic optic neuropathy Papilloedema Grade 4 hypertensive retinopathy Lebers hereditary optic neuropathy Toxic & metabolic optic neuropathy Intracranial / orbital space occupying lesion

Treatment Based on the specific cause identified In case of idiopathic / demyelinating disorder spontaneous recovery occur In case of infections appropriate antimicrobials are taken

Parasitic infestations Cysticercus cellulosae rarely effects optic nerve resulting in profound visual loss Treatment include High dose of steroids Oral albendazole Surgical removal of cyst with poor outcome

Sarcoid optic nueropathy It include granulomatous infiltration of optic nerve It results in white lumpy swellings of optic nerve head Treatment include corticosteroids

OPTIC ATROPHY Def:- it is the term usually applied to the condition of thedisc following degeneration of optic nerve Injury to nerve fibers in any part of their course from retina to lateral geniculate body leads to degeneration of both cerebral side and ocular side

Various types Consecutive optic atrophy follows extensive disease of retina from destruction of ganglion cells as in pigmentary retinal dystrophy or occlusion of central artery Secondary/post neuritic atrophy break in continuity of the fibers may be at the disc itself such as results from strangulation occuring in Pappilitis Neuroretinitis Papilloedema # of base of skull Severe retrobulbar neuritis

Primary atrophy without local disturbences but associated with general disease usually of C.N.S, toxic neuropathy or any discoverable cause Glaucomatous atrophy accompanied by enlargement and excavation of optic disc cup

Aetiology Disease or poisoning of visual neuron proximal to disc Multiple sclerosis Lebers disease Compressive space occuping lesions in orbit or cranium Many exogenous poisons Tabes  classical cause

Clinical features Alteration in colour of the disc and changes in blood vessel Pallor is not due to atrophy of nerve fibers but due to loss of vascularity, secondary to obliteration of vessels Primary atrophy Grey or white disc with greenish or bluish tint Stippling of lamina cibrosa Slight cupping distinguished from glaucomatous cupping

Secondary atrophy Consecutive atrophy Total optic atrophy If pallioedema is present it is due to increased intra cranial pressure It helps to differentiate whether it it attacked anormal disc or one which is chocked Consecutive atrophy Yellowish waxy apperence of the disc Edges are less sharply defined Vessels are markedly contracted Total optic atrophy Pupils dilated and do not respond to light When unilateral consensual light reflex is exaggerated

Partial optic atrophy Treatment Central vision is depressed There is concentric field contraction of the field With or with out scotoma ; relative or absolute Treatment Not effective Prognosis depends on early control of causal factors

Compressive neuropathys Direct pressure on opti nerve or chiasma Orbital masses Pituitary tumours Craniopharyngiomas Meningiomas optic nerve tumours Aneurysms arising from internal carotid arteries opthalmic artery

Clinical features Slowly progressive unilateral visual loss Bilateral involvement occurs if posterior optic nerve or chaisma is effected Critical signs  visual loss Field deficits Relative afferent pupillary defect Optic disc is usually pale but can be normal initially or swollen and edematous Other signs may be proptosis , opticociliary shunt vessels

THANK YOU PRESENTED BY J.V.S.KISHORE

SOURCE PARSON INTERNET