Neuroophtalmology

1. dr n. med. Karolina Kaźmierczak Neuroophtalmology

2. Opticnerve (ON) Structure: • Beginning: ganglion cells; : finish (mostly) lateral geniculate body • Afferent nerve fibres (1- 1,2 mln); divided on 600 bundles • Oligodendrocyte– axon myelination • Microglia – apoptosis • Astrocyte – basis for axons and other cells, inflammation • Optic nerve sheath : dura, arachnoid and pia mater ; between arachnoid membrane and pia mater – subarachnoid space (cerebrospinal fluid) Optic nerve diameter : 1,5 mm (intrabulbar part) 3,0 mm (retrobulbar part – with myelin) 6,0 mm (additional with optic nerve sheath)

3. Optic nerve length: 3.5 – 5.5 cm Intrabulbar part= 1.5 – 2.0 mm Intra orbital part (S-shape)= 24 – 30mm Intra canalicular part = 5 – 10 mm Opticnervesheathconnectedwithperiosteum! Intra cranial part = 5-6 – 13 mm

4. Clinicalsymptoms of theopticchiasmdamage Damage in the optic chiasm: Bitemporal hemianopsia (lost of vision laterally in both visual fields) Damage to the optic tract posterior to the optic chiasm: Homonymous hemianopsia (lost of vision on the side opposite to the damage) Damage to the optic nerve anterior to the optic chiasm: Unilateral blindness (lost of vision in the eye on the same side as the damage)

5. GOLD STANDARD !! Evaluation of the optic nerve function : Visual acuity (Snellen charts) Pupil reaction Visual field (perymetry) Color vision (color test) Light brightness sensitivity Contrast sensitivity (CST) Visual evoked potentials (VEP) Evaluation of the optic nerve structure : MRI - brain damage, optic nerve diameter Gdx – evaluation of the RNFL OCT – evaluation of the RNFL opticnerve Diagnostics

6. Photoreceptors I neuron (afferent ) Photosensitive ganglion cellsconveyinformation (via opticnerve) bilaterallyto pretectalnucleiof theuppermidbrainbypassingthelateralgeniculatenucleus and theprimaryvisualcortex strony!) II neuron (interneuron) Fromthepretectalnucleus, axonsconnect to neuronsintheEdinger-Westphal nucleus, whoseaxons run alongboththeleft and rightoculomotornerves (consensualreaction!) NormalpupilLARY RESPONSE – thepupillarylightreflexpathway III neuron (efferent preganglial) Parasympatheticneuronsfromtheoculomotornervesynapse on ciliary ganglion neurons IV neuron (efferent postganglial) Shortcliliarynervesleavetheciliary ganglion to innervate theirissphinctermuscle of theiris

7. triad of „near response”: ACCOMMODATION, CONVERGENCE, BOTH PUPILS CONSTRICTION (miosis) accommodation, convergence, and pupillary constriction are associated movements and are not tied to one another in the manner usually referred to by the term reflex. They are controlled, synchronized, and associated by supranuclear connections, but they are not caused by one another (co -movements – one can occur in the absence of the other ) with a near stimulus, both the accommodative neurons (which mediate ciliary muscle contraction) and light reflex neurons (which mediate iris sphincter contraction) are stimulated from a supranuclear level. The preganglionic and postganglionic light reflex pathways make use of the same neurons to mediate pupil contraction to either near or light stimuli NORMAL PUPILLARY RESPONSE – NEAR PUPIL REFLEX

8. DEFECTIVE PUPILLARY LIGHT REACTION ASSOCIATED WITH VISUAL LOSS AFFERENT PUPILLARY DEFECTS (symmetricpupillarysize!) Deafferented pupil (amaurotic pupil) Causes: absence of anyopticnerveorretinalfunction, orboth (e.g. severe trauma of theeye) Symptoms: • No lightperception (NLP) • Symmetricpupillarysize • The pupil isunreactive to lightstimuli • Ifthefelloweyeisnormal and lightisdirectedatit, thepupillaryreactionintheaffectedeye (consensual) should be intact Relative afferent pupillary defect (RAPD) (Marcus – Gunn pupil) Causes: usually in unilateral optic disease or sever retinal disease (but also in assymetric chiasmal disorders, optic tract lesions, amblyopia) Symptoms: • Visual acuity: from 20/20 (only blurred vision) to light perception (LP) • Symmetric pupillary size • Paradoxal pupillary light reaction (swinging flashing test)

9. A dialted pupil accompanied by eyemovementoreyelidabnormalitiessuggests a lesionproximal to theciliary ganglion (preganglionic), while an isolateddilated pupil would be morelikely associated withpostganglionicprocess. Causes of defective pupillary reactions to light generally unassociated with visual loss – DEFECTIVE PUPILLARY LIGHT REACTION UNASSOCIATED WITH VISUAL LOSSPUPILLARY LIGHT-NEAR DISSOCIATION (asymetricpupillarysize!)

10. DEFECTIVE PUPILLARY LIGHT REACTION UNASSOCIATED WITH VISUAL LOSS (PUPILLARY LIGHT-NEAR DISSOCIATION )ARGYLL – ROBERTSON PUPIL • - small, slightly irregular • – does not react to light • - dilate poorly in the dark • – brisk near response • - reacts to accommodation • Causes: • • syphilis • • diabetes • pinealoma

11. DEFECTIVE PUPILLARY LIGHT REACTION UNASSOCIATED WITH VISUAL LOSSPUPILLARY LIGHT-NEAR DISSOCIATION - TONIC PUPILS • Causes: • Adie’s syndrome(Holmes-Adie syndrome) reduced tendon reflexes (knee, ankle), orthostatic hypotension • Local ocular processes that affect the ciliary ganglion or short ciliary nerves: • - orbital trauma • - sarcoidosis • - viral illnesses (e.g.varicella) • - ischaemia (e.g. GCA) • 3. Reflecting autonomic dysfunction – may occur in association with: • - neurosyphilis • - advanced DM • - dysautonomias • - amyloidosis

12. DEFECTIVE PUPILLARY LIGHT REACTION UNASSOCIATED WITH VISUAL LOSS - THIRD NERVE PALSY • 1. Pupil – involving third nerve palsy • - pupil is large and does not constrict to light, eighter directly or consensually, or near stimuli (internal ophthalmoplegia) • - usually either ptosis or a deficit in adduction, depression, or elevation of the eye, or combination of them (external ophthalmoplegia) will assist • Causes: nuclear, fascicualr and subarachnoid palsies (meningitis, aneurysmal compression) • Pupil – spearing third nerve palsy • - the eye-movements or eyelid are affected, but the pupil retains normal size and reactivity • Causes:diabetes, hypertension (elderly people)

13. Disorders of pupillarydilation: oculosympatheticdisruption (Hornersyndrome) • Symptoms: • Triade: miosis, pseudoendophthalmos and mild • upper and lowereyelidptosis, • anisocoriaworseinthedark • facilalanhidrosis • ocularhypotony (transient) • irisheterochromia(in congenitalcases, typically) • Pharmacologictesting: • Graterthan 1 mm of relativeanisocoriafollowing • installation of 10% cocaineeye drops intobotheyes Causes of Horner syndrome according to affected neuron

14. Optic disc drusen (hyaline bodies) Rare complications Superficial (exposed) • composed of hyaline-like calcific material • within the substance of the optic nerve head • the waxy pearl – like irregularities • juxtapapillary CNV, disc neovascularization, central retinal arterial and venous occlusion Ultrasonography - drusen lie deep beneath the surface of the disc - elevated disc with a scalloped margin without a physiological cup - hyperaemia is absent and the surface vassels are not obscured - anomalous vascular patterns such as early branching, increased number of major retinal vessels Detect calcific deposits that show high acoustic reflectivity CT • CT shows disc calcification but is less • sensitive than USG • sometimes drusen detected incidentally during • investigation of other pathologies

15. Myelinatedretinalnervefibers Peripapillary Isolated peripheral Diffuse • - anomalous white patches of myelin which are often continguous with • the optic disc and typically contained within the nerve fiber layer • the edges appear serrated of feathery as the myelination aligns along • the nerve fibers

16. Acquiredopticneuropathies • Opticneuritis • Papilloedema • Ischaemicopticneuropathy • Toxicopticneuropathy

17. Optic neuritis (ON)- podział na podstawie klasyfikacji oftalmoskopowej

18. Papilloedema Definitions: „PAPILLOEDEMA”– is swelling of the optic nerve head, secondary to raised intracranial pressure. It is nearly always bilateral, although may be asymmetrical. „Disc swelling”– all other causes of disc oedema in the absence of raised intracranial pressure – usually produce visual impairment. All patients with papilloedema should be suspected of having itracranial mass unless proved otherwise. Exceptions: • Tumors of the cerebral hemispheres (tend to produce papilledema later than those in the posterior fossa) • Glial scarring of the optic nerve head in cese of previous papilloedema Foster Kennedy syndrome –ipsilateral disc pallor, secondary to optic nerve compression, and contralateral paiplloedema .

19. Stages of papilloedema • Early papilloedema • 2. Established (acute) papilloedema • Chronic papilloedema • 4. Atrophic papilloedema

20. 1. Early papilloedema • visual symptoms are amsent and visual acuity normal • optic disc show hyperaemia and mild elevation • the disc margins (initially nasal, later superior, inferior and temporal) appear indistinct • there is loss of previous spontaneous venous pulsation • (but! About 20% of normal individuals do not manifest spontaneous venous pulsation) 2. Established (acute) papilloedema • transient visual obscurations may occur in one or both eyes, lasting a few seconds, often on • standing or bending forward • VA is usually normal • optic discs show severe hyperaemia, moderate eleveation with indistinct margins and obscuration of • small surface vesseles • venous engorgement, peripapillary flame – shaped haemorrhages and frequently cotton – wool spots • as the swelling increases, the optic nerve head appears enlarged and circumferential retinal folds • may develop on its temporal side • hard exudates may radiate from the centre of the fovea in the form of a „macular fan” – an • incomplete star with the temporal missing • the blind spot is enlarged

21. 3. Chronic papilloedema • VA is variable and the visual fields begin to constricts • optic discs are markedly elevated, with a „champagne cork” • appearance • cotton – wool spots and haemorrhages are absent • opto – ciliary shunts and drusen – like crystalline deposits • (corpora amylacea) may be present on the disc surface 4. Atrophic papilloedema (secondary optic atrophy) • VA is severely impaired • the optic discs are a dirty grey colour, slightly elevated, with few • crossing blood vessels and indistinct margins

22. Ischaemicopticneuropathy 1. Anterior ischaemic optic neuropathy (AION) • Non – arteritic AION • Arteritic AION 2. Posteriorischaemicopticneuropathy (PION) (due to infarction of theretrolaminar opticnerve • Signs : • VA impairement– moderate to severe • usually altitudinal defect in visual field • dyschromatopsia proportional to the level of visual impairement • disc pallor associated with diffuse or sectoral oedema, often with peripapillary splinter – shaped haemorrhages • the oedema gradually resolves and pallor ensues

23. Anteriorischaemicopticneuropathy

24. Non – arteritic AION Acute stage Late stage • inferior sectoral , later diffuse • oedema • splinter haemorrhagies • dilated capillaries or luxury • perfusion on the disc surface • mild or non-existing optic disc • swelling • palor of the optic disc (secondary optic neuropathy) Cause: infarction of the optic nerve head caused by occlusion of the short posterior ciliary arteries Arteritic AION • Cause: Giant cell arteritis (GCA) • (vasculitis involves large and mid-sized arteries containing an elastic lamina) • Signs: • tenderness and loss of pulsation • of one or both temporal arteries • a strikingly pale („chalky white”) oedematous • disc • occasionally AION may be combined with • occlusion of the cilioretinal artery • - Over 1-2 months, the swelling gradually resolves and optic atrophy ensues • Establishing the diagnosis: • an elevated C-reactive protein (CRP) • positive temporal artery biopsy • abnormal fluorescein angiography (FA) • (delayed choroidal filling and focal, • patchy perfusion defects

25. Toxicopticneuropathy Nutritional optic neuropathy (tabacco-alcohol amblyopia) – lack of protein and the B vitamins. Signs: • insidious onset, progressive, • bilateral, usually symmetrical visual impairement associated with dyschromatopsia • optic disc may be normal; sometimes subtle temporal pallor, splinter-shaped haemorrhages on or around the disc or minimal disc oedema • Visual field defects are billateral, relatively symmetrical (centrocaecal scotomas) • Treatment: well – balanced diet, weekly injections of 1000 units of hydroxycobalamin for 10 weeks • Other causes of toxic optic neuropathy: • drugs (ethambutol, izoniazyd, amiodarone, wigabatryn, immunosupressive drugs, quinine, oral contraception, some antibiotics, e.g. streptomycin, chloramphenikol, sulphonamidum) • methanol (severe visual loss, optic disc swelling, xanthopsia – poor prognosis)

26. Opticnerveatrophy Podział: • Onset of the atrophy - Hereditary optic neuropathies/atrophies (Leber,s hereditary optic neuropathy (LHON), dominant optic atrophy (Kier DOA), recessive optic atrophy (Behr syndrom), Wolfram sydrome (DIDMOAD) - Acquired optic atrophies (ON, papilloedema, AION) • Ethiology of the atrophy • Primary optic nerve atrophy (efferent, e.g. after ON ; occurs without significant swelling or reactive gliosis – the disc pallor associated with sharp margins ) • Secondary optic nerve atrophy (afferent, after disc swelling; there is a haze to the disc surface or overlying nerve fibre layer which obscures the disc margin ) C. Spectrum of the atrophy • Partial (sectoral ) optic nerve atrophy • Total optic nerve atrophy • One or both eyes • Unilateral (e.g. after ON) • Bilateral (e.g. papilloedema, NAION)

27. Chiasmaldiseases Causes: • Tumours (pituitary adenomas, craniopharyngioma, glioma, meningioma, chordoma, dysgerminoma, nasopharyngeal tumours and metastases) • Non – neoplastic masses (aneurysms, Rathke pouch cyst, fibrous dysplasia, sphenoidal sinus mucoceles, arachnoid cyst) • Miscellaneous(demyelination, inflammation, trauma, radiation – induced necrosis, vasculitis)

28. Tumors as a cause of thedamage of theopticchiasm Location of the scotomas in visual fields and tumors : • Pituitary adenoma (A)– initially superior homonymous quadrantanopsia • Craniopharyngioma(B) – initially inferior homonymous quadrantanopsia A B

29. Intracranialaneurysm • Their prevalence ranges from 1% to 6% among adults (are multiple in 25% of cases) • 85% arise from the anterior half of the circle of Willis • The majority remain asymptomatic during life, although occasionally they may cause the following life-threatening complications Neuroopthalmologic aspects: • Ocular motor nerve palsies (isolated third nerve palsy, isolated sixth nerve palsy, combined palsies) • Visual loss (monocular – the internal carotid artery aneurysm.; visual field defects – a giant aneurysm at or near the origin of the ophthalmic artery ) • Terson syndrome – the combination of occular haemorrhage and subarachnoid haemorrhage secondary to aneurysmal rupture, most commonly arising from the anterior communicating artery)

30. Effect of theaneurysm on theoptic system 1. Pressure effects warning mass signs (giant aneurysms, >25mm) 2. Subarachnoid, haemorrhage The most common symptom is headaches; the interval beetwen warning mass signs and rupture varies from 1 day to 4 months Sudden onset of headache, photophobia, clouding consciousness, vomiting, sign of meningeal irritation (positive Kernig sign)