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NEURO-OPHTHALMOLOGY. Clinical Examination. Visual Acuity Colour Vision Visual Fields Pupils. Normal Eye and Optic Disc. Cupped disc. The swollen optic disc. Papilloedema Papillitis Malignant hypertension Ischaemic optic neuropathy Diabetic optic neuropathy CRVO
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Clinical Examination • Visual Acuity • Colour Vision • Visual Fields • Pupils
Normal Eye and Optic Disc Cupped disc
The swollen optic disc • Papilloedema • Papillitis • Malignant hypertension • Ischaemic optic neuropathy • Diabetic optic neuropathy • CRVO • Intraocular inflammation
25 y.o. female Reduced VA Pain with eye movement Colour desaturation RAPD
65 y.o. male Reduced VA Painless loss of vision Essential hypertension Smoker
The pale optic disc • Congenital • Secondary to • raised ICP • vascular retinal disease • optic neuritis • optic nerve compression • trauma • Glaucoma
Papilloedema Blurred optic disc margin • Disc swelling secondary to raised ICP • Headache • Worse in the morning • Valsalva manouver • Nausea and projectile vomiting • Horizontal diplopia (VI palsy) • Causes • Space occupying lesion • Intracranial hypertension • Idiopathic • Drugs • Endocrine • Severe hypertension Haemorrhages Small optic cup CWS Disc pallor Vessel attenuation
Pupils • First Order – Retina to Pretectal Nucleus in B/S (at level of Superior colliculus) • Second Order – Pretectal nucleus to E/W nucleus (bilateral innervation!) • Third Order – E/W nucleus to Ciliary Ganglion • Fourth Order – Ciliary Ganglion to Sphincter pupillae (via short ciliary nerves)
Constricted (mioisis) Sympathetic (pupillodilator) denervation Drugs Pilocarpine Morphine Dilated (mydriasis) Parasympathetic (pupilloconstrictor) denervation Lesion of the third CN Drugs Atropine Cocaine Pupil
Horner’s • Oculosympathetic paresis • Ptosis • Miosis • Ipsilateral anhidrosis • Does not dilate with cocaine 4%
Sympathetic Pathway • First Order – Posterior Hypothalamus to Ciliospinal centre of Budge (C8-T2) (Uncrossed in Brainstem) • Second Order – Ciliospinal centre of Budge to Superior Cervical Ganaglion • Third Order – Superior Cervical Ganglion to dilator pupillae muscle. (Close to ICA and joins V1 intracranially)
Internal Carotid Dissection Herpes Zoster • CVA • Tumour • Otitis Media • Tolosa-Hunt Sy. Pancoast bronchogenic carcinoma
Causes of Horner’s pupil • Central – B/S lesions (tumours, vascular and MS) Syringomyelia, Lat. Med. Syn., S.C. ca. • Preganglionic – Pancoast tumour, Carotid & Aortic aneurysms, Neck lesions/trauma. • Postganglionic – Cluster headaches, Nasopharyngeal tumours, Otitis media, Cavernous sinus mass and ICA disease. • Miscellaneous – Congenital (brachial plexus injury) Idiopathic.
Argyll-Robertson pupil Small, irreg Does not react to light Reacts to accommodation Causes syphilis diabetes Miotonic pupil (Adie’s syndrome) Dilated Poor response to light and convergence. Constricts with weak Pilocarpine Holmes-Adie syndrome Reduced tendon reflexes (Knee, ankle) - Orthostatic hypotension Afferent & efferent defects
Third nerve palsy Double vision Eye turned down & out Ptosis Dilated pupil & headache Compressive lesion Sixth nerve palsy Double vision Eye turned in Ocular motility abnormalities
Cranial Nerve Palsies Looking straight ahead
Posterior communicating artery aneurysm Chiasma Posterior cerebral artery III CN
Internuclear Ophthalmoplegia • Defective adduction of the ipsilateral eye • Nystagmus of the contralateral (abducting) eye • NORMAL CONVERGENCE • Causes • Young patients • Bilateral • Demyelination • Older patients • Unilateral • Vascular, tumours
Myasthenia Gravis Fatigability Double vision Lid twitch Ptosis Normal reflexes & sensation
INVESTIGATIONS MG • Anti ACh receptor Ab’s • Electromyography • Tensilon test • Edrophonium blocks acetyl-cholinesterase • Beware of cholinergic cardiac effects. Use with Atropine 0.6mg • Thoracic CT and MRI to rule out thymoma ACh Anti AChR Ab’s AChR
Localising the lesion • Monocular visual field defects indicate lesions anterior to the optic chiasm • Bitemporal defects are the hallmark of chiasmal lesions • Binocular homonymous hemianopia result from lesions in the contralateral postchiasmal region • Binocular quadrantanopias reflect optic tract lesions