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105 Cards in this Set

  • Front
  • Back
The most common causes of blindness in Australia are:
Aged-related Macular Degeneration (AMD)
Glaucoma
Cataracts
Diabetes
Myopia
Eye presentations to emergency departments and GP’s:
1. Visual loss
2. Red eye
3. Trauma
4. Foreign body
5. Chemical injury
6. Diplopia
7. Flashes and floaters
Visual loss Hx
1. Timing
a. What were you doing?
b. When did the problem start?
c. Was the onset sudden or gradual?
d. What has happened to vision since the problem began?
e. Has this happened before?
2. Trauma/foreign body?
3. Unilateral or bilateral loss of vision?
4. Painful or painless eye(s)?
5. Red or white eye(s)?
6. Contact lens wear? Glasses (reading or distance or both)?
7. Prior eye surgery or laser?
8. Microvascular risk factors – DM? HT? Chol? Smoking?
9. Always ask about Giant Cell Arteritis – Headache? Jaw claudication? Stiffness in shoulders or hips (polymyalgia rheumatica)? Weight loss? Fevers/night sweats?
Visual loss Examination
1. Visual acuity
2. Visual fields
3. Pupils
4. Red reflex (direct ophthalmoscope), try to view the fundus
5. Is the eye white or red?
6. Eye movements/ptosis
7. Slit lamp biomicroscope
The ideal pupil-dilating agent for fundoscopy?
tropicamide 1%
Tropicamide pharmacology
antimuscarinic
Tropicamide actions
mydriasis
cycloplegia
Tropicamide duration of effect
4–8 hours
Tropicamide onset of action
15-30 minutes
cycloplegic agents
usually antimuscarinics

atropine, cyclopentolate, homatropine, scopolamine, tropicamide
Indications of cycloplegic drugs
- uveitis
- to paralyze the ciliary muscle in order to determine the true refractive error of the lens
- with mydriatic effects for ophthalmic examination
Define uveitis
inflammation of uvea (ciliary body, iris, choroid)
Classifications of uveitis
anterior
intermediate
posterior
panuveitis
Anterior uveitis
anterior chamber & iris

(majority of cases)
Intermediate uveitis
vitritis (inflammatory cells in the vitreous cavity)
Posterior uveitis
retina & choroid
Pan-uveitis
inflammation of all the layers of the uvea
commonly floaters are due to
degenerative changes of the vitreous humour
long sighted =
hyperopia
short sighted =
myopia
presbyopia
hardening of the lens associated with aging, resulting in loss of accomodation

bifocal lenses - top half concave for distance vision & bottom half convex for close-up vision
normal optic nerve
(central cup is small and the neuroretinal rim is thick)
glaucomatous optic nerve is characterized by vertical elongation of the cup and a large notch inferiorly
Optic neuropathy in glaucoma may be characterized by significant loss of neuroretinal rim tissue
floaters
Describe the passage of aqueous humour
ciliary body → aqueous humor → pupil → anterior chamber → trabecular meshwork in angle of anterior chamber
Describe the image & lens relationship
Normal disc/cup ratio?
disc/cup ratio 0.3 or one third
Define optic disc
AKA optic nerve head (physiological blind spot)
- where ganglion cell axons exit the eye to form the optic nerve
- shaped like a doughnut with a pink neuroretinal rim and a central white depression called the physiologic cup
Parts of the optic nerve
Intraocular (the optic nerve head)
Intraorbital (between globe and optic canal)
Intracanalicular (within the optic canal)
Intracranial (between optic canal and chiasm)
normal fundus
alternative to tropicamide in dilating for fundoscopic exam?
phenylephrine 2.5%
(modest dilation, delayed for 30 minutes)
neuroretinal rim
carries the axons of the retinal ganglion cells
COLOUR of the neuroretinal rim?
normally orange-pink

If its axons die (inflammation, infarction, compression) the rim will turn white
DISTINCT neuroretinal rim?
- Some fuzziness of the nasal margin is acceptable
- Otherwise swollen
Causes of optic disc oedema?
↑ ICP
optic nerve inflammation & infarction
Commonest cause of pathologic optic disc cupping
Glaucoma
Diameter of physiologic cup?
1/3
should not exceed 0.5
Where do the retinal arteries and veins emerge from?
retinal arteries and veins emerge from the nasal side of the optic disc

Vessels directed temporally have an arching course; those directed nasally have a radial course.
Appearance of retinal arteries and veins?
Arteries are brighter red and narrower than veins
outer retina (rods and cones and retinal pigment epithelium)

is supplied by the
choroidal circulation
Appearance of Fovea
2.5 mm-diameter area that looks slightly darker than the surrounding retina because of increased pigment

It is centered about 2 1/2 disc diameters temporal to the optic disc. The fovea lies in the center of the macular region.
the fovea is made up of
cones exclusively
the fovea processes
high-contrast discriminative vision (visual acuity) & colour vision
List some macular disorders
AMD
diabetic macular oedema
toxoplasmosis
cherry-red spot
optic disc cupping

thin neuroretinal rim
large cup-to-disc ratio (0.8)
Pupillary light reflex
Saggital section eye in orbit
Chalazion
meibomian cyst
- chronic sterile lipogranulomatous inflammation involving the sebaceous glands of the eyelid
a secondarily infected chalazion
internal hordeolum
Chalazion - presentation?
- gradually enlarging painless nodule
- any age
What are the types of secretory product from an exocrine gland?
Serous (watery) - protein rich
Mucous (viscous) - CHO rich
Sebaceous (oily)
Hordeolum
an infection of the sebaceous gland of the eyelid
external hordeolum
=stye

acute staphylococcal abscess of a lash follicle & gland of Zeis
Styes more commonly presents in
children
Treatment of Stye
topical antibiotics
warm compresses
epilation of associated eyelash
chalazion vs. hordeolum
chalazion is a painless lump away from the lid margin
vs.
hordeolum is a painful red lump near the lid margin
lamina cribrosa
layer of optic nerve head consisting of sheets of connective and elastic tissue, containing fenestrations which give passage to the nerve fibre bundles and retinal blood vessels.
- maintains IOP against a gradient between the intra-ocular and extra-ocular spaces
- Being structurally weaker than the much thicker and denser sclera, the lamina cribrosa is more sensitive to changes in the intraocular pressure and tends to react to increased pressure through posterior displacement, thought to be one of the causes of nerve damage in glaucoma
assessment of optic disc mnemonic
the 3 Cs
cup, colour, contour
optic neuropathy causes mnemonic
NIGHT TICS

Neuritis
Ischaemic
Granulomatous
Hereditory
Traumatic
Toxic
Irradiation
Compression
ddx unclear contours of optic disc
- swollen in papilloedema due to ↑ ICP
- blurry with optic disc drusen
Normal colour of optic disc
orange-pink donut with a pale centre
Ddx:
loss of orange-pink colour to optic disc to pale
optic atrophy:
advanced glaucoma
optic neuritis
arteritic/non-arteritic ischaemic optic neuropathy
compressive lesion
Normal colour of optic disc cup
pale centre surrounded by an orange-pink rim
an increased cup to disc ratio may indicate
a decrease in the quantity of healthy neuro-retinal tissue and hence, glaucomatous change
Optic disc edema is commonly caused by
The 4 "I's":

increased intracranial pressure (papilledema)
infarction
inflammation
infiltration (by cancer)

Compression and toxins are other causes
"sheathing" or perivenous lymphocytic infiltration = retinal vasculitis

sarcoidosis, Behçet's Disease, MS, idiopathic
cotton wool spots

- caused by retinal nerve fiber layer microinfarcts
- located around the optic disc and along the temporal vascular arcades
Roth Spot
- white-centered hemorrhage
- cotton wool spot surrounded by hemorrhage
- The cotton wool comes from ischemic bursting of axons; the small hemorrhage comes from ischemic bursting of a pre-capillary arteriole
- not specific to bacterial endocarditis
Retinal drusen

- tombstones of dead retinal pigment epithelial cells
- commonest cause AMD
Causes of cotton-wool spots
Any process that occludes small retinal arterioles

hypertension, diabetes, HIV, severe anemia or thrombocytopenia, hypercoagulable states, connective tissue disorders, viruses, lues, Behçet's
greatest threat to vision in AMD
development of submacular neovascularization, which can cause bleeding in the retina
AV nicking
acute optic disc oedema
boat hemorrhage
dot hemorrhage
flame hemorrhage
cotton wool spots
retinal neovascularisation
chronic optic disc oedema
retinal hemorrhage types
retinal drusen
subtle optic disc oedema
hard exudates
silver wiring
copper wiring
yellow-white retina DDX
Sjögren's Syndrome assc ophthy cond'n
Keratitis sicca
Adult Rheumatoid Arthritis assc ophthy cond'n
Keratitis sicca, Scleritis
Relapsing Polychondritis assc ophthy cond'n
Scleritis, Orbital pseudotumor
Wegener's Granulomatosis assc ophthy cond'n
Scleritis, Sclerokeratitis, Orbital pseudotumor
Reiter's Syndrome assc ophthy cond'n
Uveitis, Conjunctivitis
Behçet's Disease assc ophthy cond'n
Uveitis, Retinal vascular occlusion
Juvenile Pauciarticular Arthritis assc ophthy cond'n
Uveitis
Sarcoidosis assc ophthy cond'n
Uveitis, Retinal vascular occlusion
Ankylosing Spondylitis assc ophthy cond'n
Uveitis
Lupus Erythematosus assc ophthy cond'n
Retinal vascular occlusion
Polyarteritis Nodosa assc ophthy cond'n
Retinal vascular occlusion
Scleroderma assc ophthy cond'n
Retinal vascular occlusion, Keratitis sicca
Primary CNS Angiitis assc ophthy cond'n
Retinal vascular occlusion
Giant Cell Arteritis assc ophthy cond'n
Ischemic optic neuropathy