E-mail: Shaf3y_h@hotmail.com facebook/shafie eye clinic

Symptoms & Signs in Clinical Medicine

By/Mohamed Ahmed El –Shafie

Assistant Lecturer in ophthalmology department KafrELShiekh University

Anatomy of optic nerve• Optic nerve- more than 1 million axons.• Consisting of axons originating from ganglion

cells.

• Starts from optic disc upto optic chiasma.• Contains the afferent fibers of light reflex.

• Elongated tract of white matter • Not covered by neurilemma.

2

• Optic nerve divided in topographic areas:

Intraocular portion.Intraorbital portion.Intracanalicular portion.Intracranial portion.

3

4

Intraocular optic nerve

• 1 mm in length.• 1.5 mm diameter.• Which expands approximately 3-4 mm behind

the sclera.

5

Intraorbital optic nerve

Relation of ophthalmic arteryAt the optic foramen: inferior and lateral

Lateral to optic nerve (in posterior orbit)

Inferior division of 3rd nerve-Sixth NerveCiliary ganglionNasociliary artery

6

At the orbital apex – optic nerve surrounded by annulus of Zinn.

Blood supply: Ophthalmic artery with meningeal branches

7

Intracanalicular optic nerve

• 9 mm

• Tightly fixed within the canal (compressive optic neuropathy Optic nerve edema)

• Blunt trauma

Blood supply: Pial branches from ophthalmic artery.

8

Intracranial optic nerve

• Length-10mm• Diameter-4.5mm

Extends post & medially ascending at an angle of 45º to join the chiasma

Blood supply: pial vessels arising from ICA branches from ant cerebral and anterior communicating artery

9

Normal optic disc

- Color: Orange or pink

- Margin- Counter- Crescent- Distribution of veins.

Why the normal disc is pink?

• Thickness and the cytoarchitecture of fiber bundles passing between glial columns containing capillaries

12

• Pathologies of the optic nerve, even though not always detected on ophthalmoscopic exam, may compromise its function and cause the following sign;

Visual Acuity Near vision

- Reading from a book

Far vision

- Snellen chart.

- Ishihara charts

Dyschromatopsia • Impaired color vision = 94%• Desaturation

• – eg: red = dark/ beached

• Distinguishes b/w macular lesion

confrontation

Kinetic perimetry Static perimetry Kinetic perimetry Static perimetry

• all patients show V.F abnormalities in acute phase

Central ⁺⁺⁺, peripheral⁺, particular region⁺ • If Vn severely impaired – confrontation test

• Vision improved – • kinetic Goldman Perimetry ( only central scotoma)• Automated static Perimetry

• Focal defect – • Altitudinal • Arcaute • Nasal step defect

• Stimulus• Receptors• Afferent• Center• Efferent• Effector organ• Effect

Pup. light reflex

VEDIO

VEDIO

Afferent pupillary defect • In the absence of an optic nerve lesion in the fellow eye, RAPD

can be demonstrated by swinging flash light

• -ve RAPD in recurrent attacks

Causes:Causes:

• Optic neuropathyOptic neuropathy• Total retinal detachmentTotal retinal detachment• Dense vitreous haemorrhageDense vitreous haemorrhage• Dense amblyopiaDense amblyopia

VEDIO

Contrast sensitivity

• - good for subclinical ON

Optic Disc SwellingOptic Disc Swelling How do you approach? How do you approach?

Papilloedema Papilloedema vsvs Optic Neuritis Optic Neuritis

Papilloeodema Definition , Non-inflammatory swelling of Optic disc Causes1. Raised Intracranial Pressure:

- Space-occupying lesions-Occlusion of :retinal veins cavernous sinus-Other cause.

Optic Neuritis (ON) • Inflammation of optic nerve - ON

• Associated with swollen disc – papillitis

• Normal disc – retro bulbar ON

Papilledema Optic neuritis AION increased ICP Inflammatory swelling Vascular accident (occlusion of

short posterior ciliary artery causing infarction

Brain tumors , hematomas,meningitis

Multiple Sclerosis is highly associated

Hypertension, giant cell arteritis, hypercoagulable state

Bilateral , may be asymmetric

Unilateral Unilateral

28

Headache, nausea, vomittingHeadache, nausea, vomittingNo visual loss usually,No visual loss usually, only enlarged blind spot only enlarged blind spot

Retrobulbar pain on ocular Retrobulbar pain on ocular movement, early central movement, early central scotoma, decreased acuity, scotoma, decreased acuity, impaired color vision,impaired color vision,presence of APDpresence of APD

Acute painless visual loss, usually Acute painless visual loss, usually hemialtitudinal defect involving hemialtitudinal defect involving the lower visual fieldthe lower visual field

Variable degree of disc swelling, hemorrhages

Fewer hemorrhages and cotton wool spots

Pale segmental swelling and splinter hemorrhages at its margins

Prognosis usually good if primary cause of increased ICP is treated

Vision usually returns to normal

Poorer prognosis, permanent loss. Second eye is involved in one third of cases.

OPTIC ATROPHYDegeneration of the optic nerveoccurs as an end result of any pathologic process that damages axons

Ophthalmoscopic classification Primary optic atrophySecondary optic atrophyConsecutive optic atrophyGlaucomatous optic atrophy

Primary optic atrophy

Consecutive optic

atrophy

Secondary optic atrophy

Glaucomatous optic atrophy

chalky white or white

Disc appears yellow waxy

dirty white in colour

Pale disc

Margins are sharply outlined

edges are not so sharply defined

Edges are blurred,.

Edges well defined

Lamina cribrosa is clearly seen at the bottom of the physiological cup

physiological cup is obliterated

deep and wide cupping of the optic disc and nasal shift of the blood vessels

Major retinal vessels and surrounding retina are normal

Retinal vessels are attenuated

vessels are attenuated and perivascular sheathing

Normal

32