Week 2- Clinical Flashcards
Define sympathetic ophthalmia
Rare, bilateral, granulomatous uveitis as a result of trauma or surgery to one eye
Give an example of an eye condition that is an example of Type I hypersensitivity
Acute Allergic conjunctivitis
Ocular cicatricial pemphigoid is an example of what type of immune response?
Type II hypersensitivity
Define visual acuity
Ability to distinguish between two objects at a distance
Name the charts used to measure visual acuity. How do you record data from this?
Snellen charts
distance(m)/line of letters e.g. 6/24
if only read some on that line then add negative e.g. 6/24-2
What is the average visual acuity in the population?
6/6
Why do they use mirrors to look at Snellen charts?
To achieve a 6metre distance even if the patient is only 3m from the mirror
What is the WHO definition of blindness?
Visual acuity of 3/60 or worse
What test might you use to measure visual acuity in children?
Preferential vision test
What charts are used to test colour vision?
Ishihara plates
How do the average ocular trauma causes differ between males and females?
Males- mainly 20s/30s, from assault/machinery
Females- mainly 60s+, from falls
Identify four steps which are important in ocular trauma assessment
History
Visual acuity tests
Eye examination
Fluorescein drops and slit lamp
What is hyphaema?
Blood within the anterior chamber of the eye
Consider how one would remove foreign bodies from the cornea
Use slit lamp
Use local anaesthetic
Use edge of a needle to scoop out
Give chloramphenicol to prevent infection
Name an investigation that is essential for IOFBs
X-ray for intraocular foreign bodies
Because often shards of metal from hammering
Which penetrates the eye more deeply? alkali or acid? Give three possible presentations of this
Alkali
Eye ischaemia, Scarring, vascularisation
How do you treat chemical eye trauma?
IRRIGATION until pH normal
Identify some of the signs and symptoms of conjunctivitis
Red eye discharge Swollen Discomfort suppuration
Give three viral causes of conjunctivitis
Herpes zoster
Herpes simplex
adenovirus
What is keratitis?
Inflammation of the cornea
Name the most common cause of disciform keratitis and its treatment
Herpes viruses
Ganciclovir
What parasite is associated with contact lens use?
Acanthamoeba
What is orbital cellulitis?
Infection of the deep layer of the skin and the subcutaneous tissue in the orbit of the eye
Define sympathetic ophthalmia
Rare bilateral granulomatous uveitis that is secondary to trauma or surgery to one eye
What is cataracts?
Opacifications of the ends of the eye leading to blurred vision
Give two causes of swollen optic discs
Papilloedema
malignant hypertension
What is optic disc drusen?
Globules of mucoproteins and mucopolysaccharides that accumulate in the optic disc
What is the difference between homonymous/incongruous?
Homonymous- same part of field in each eye
Incongruous- different parts of visual field
What is the difference between hemianopic and quadratonopic?
Hemianopic- half of visual fields
Quadratonopic- Quadrant of visual fields
What are the Three Cs which should be investigated when it comes to optic disc examination
Contours- borders of the optic disc should be clear and well defined
Colour- should look orange/pink with a pale centre (orange/pink is healthy, well-perfused neuroretinal tissue.
Cup- pale cup should be a third of size of disc (0.3 cup ratio)
Ill-defined optic disc contours are a sign of what two conditions?
Papilloedema
Optic disc drusen
Summarise the causes of optic neuropathy which cause neuroretinal discolouration
Neuritis Ischaemia Granulomatous Hereditary Traumatic Toxic Irradiation Compression
How many layers are there in the retina?
10 layers
What is the most common cause of quadrantinopia? What about inferior quadrant and superior quadrant defects?
Occipital lobe stroke
Inferior- parietal lobe
Superior- temporal lobe
What is hyperopia and what is mypoia?
Hyperopia- long sightedness
Myopia- short sightedness
What lens would you give a 1. Myopic and 2. hyperopic patient?
- Diverging lens (concave)
2. converging lens (convex)
What is the difference between ametropia and Emmetropia?
Emmetropia- where no refractive error is present and so light is focused on the retina
Ametropia- where refractive error is present and so light is focused before/behind the retina
What is anisometropia?
Where there is a significant difference between right and left eye ametropia
What lens would you give a 1. Myopia and 2. hypermetropia patients?
- Diverging lens (concave/negative)
2. converging lens (convex/positive)
What is astigmatism?
Where the image of an object is distorted because not all the light rays come to focus on the retina. Due to irregular curvature of the cornea/lens. Some light hits appropriately but other rays not.
What is presbyopia?
The reduction of the ability of the eye to accommodate near vision with increasing age. Need reading glasses (convex/positive lens)
What is a lazy eye (amblyopia)?
Reduced vision due to abnormal visual development in early life.
What is the significance of pinhole acuity?
Is an indication of the best visual acuity the patient shall have after correction
What is nystagmus?
Rapid involuntary movement of the eyes
What are the four main aetiologies of visual field damage
vascular disease
space occupying lesions
demyelination (MS)
trauma/surgery
Name the angle that is opened/closed in glaucoma
iridocorneal angle
How come the fovea appears more red than the rest of the fundus?
Only possesses a single layer of ganglion cells.
Give three possible fundoscopy findings of diabetic retinopathy.
Haemorrhages (dot/blot/flame)
hard exudates
microaneurysms
Name the four areas of the retina
Superotemporal arcade
superonasal arcade
inferotemporal arcade
inferonasal arcade
What is diplopia?
double vision
How does sudden onset diplopia present?
manifest squint and diplopia (double vision)
Name the test used to identify a manifest squint. Corneal reflections are a great indicator of asymmetry
Cover test
Define the following: Esotropia, exotropia, hypertropia, hypotropia
Esotropia- outward movement of eye
Exotropia- inward movement of eye
hypertropia- downward movement of eye
hypotropia- upward movement of eye
What is chemosis?
oedema of the conjunctiva that gives the eye a boggy appearance
What is an epiretinal membrane
A thin membrane that can form over the macula of the retina that causes metamorphopsia
What is central serous chorioretinopathy? In what population is it common?
Retinal detachment in the area of the macula due to localized leakage through the RPE into the subretinal space. Common in young adult males
What group of diseases is indicated by metamorphopsia?
Macular diseases
What is metamorphopsia and what is scotoma?
m- distorted vision of objects
s- where areas of vision are absent
What is coloboma?
Absence of part of the iris leaving an irregular shaped pupil.
Identify a symptom that is common in bacterial conjunctivitis but not in viral conjunctivitis
Yellow purulent discharge rather than watery discharge
What imaging is used to aid the diagnosis of orbital cellulitis?
CT scan
What is endophthalmitis? What is the major cause of this and how is it treated?
Inflammation within the eye
Staph epidermidis
intravitreal antibiotics
Toxoplasmosis gondii and toxocara are associated with what condition?
Chorioretinitis
Nam the drug combination used to treat uveitis
Mydriatics and steroids
Identify a possible cause of CNIII palsy that is unlikely for the other cranial nerve palsies.
Aneurysm
What bilateral cranial nerve palsy may be caused by head trauma?
CNIV
What does CRAO stand for?
Central retinal artery occulsion
Describe some of the symptoms of CRAO
Sudden visual loss
painless
RAPD present
Pale retina
How does CRVO present in fundoscopy?
Dilated tortuous veins
haemorrhages
disc and macular swelling
Deep red fundus
Define glaucoma
A condition of the optic nerve where increased intravitreal pressure leads to a loss of retinal nerve fibres and results in a loss of vision.
What is the difference between open angle and closed angle glaucoma?
OA- Increased pressure due to a blockage of the trabecular meshwork
AA- Increased pressure due to blockage of the canal of Schlemm and trabecular meshwork
Give two signs of presentations of glaucoma on fundoscopy
Enlarged cups (cupping) Neuroretinal discolouration
Describe the signs and symptoms of closed angle glaucoma
Acute onset Acute red eye Nausea and vomiting headache acute visual loss glaukomflecken cloudy cornea
Identify three topical drug types used to reduce intraocular pressure in glaucoma
Beta blockers
Prostaglandins
carbonic anhydrase inhibitors
How does Papilloedema present on a fundoscopy?
swollen optic discs with irregular contours and neuroretinal discolouration
Describe the difference between the pathophysiology of wet and dry ARMD
WET- abnormal growth of new blood vessels beneath the retina lead to reduced macular function
DRY- chronic choroid ischaemia leads to degeneration of retinal pigment epithelium
Name the three main types of retinal detatchment
Rhegmatogenous
tractional
Exudative
Describe retinal detatchment.
Separation of inner nervous layer from outer Retinal Pigment Epithelium with fluid accumulating under the tear.
Define ischaemic optic neuropathy
Occlusion of posterior ciliary arteries resulting in optic nerve head neuropathy
Name a rheumatology condition that can cause ischaemic optic neuropathy
Temporal (giant cell) arteritis
Congenital, nuclear, posterior subcapsular and christmas tree are all subtypes of what condition?
Cataracts
What is cataracts?
Opacifications of the lens of the eye leading to blurred vision
Identify some of the aetiologies of cataracts
Cumulative UVB damage trauma surgery hypertension glaucoma age-related diabetes genetic
What is the most common cause of optic neuritis? How does optic neuritis present?
Multiple sclerosis
Unilateral eye pain that may improve over time
How does Horner’s syndrome present?
Miosis, anhidrosis and ptosis
Due to disorder of the sympathetic innervation in the brainstem or cervical region
What characterises Iron-containing foreign body injuries?
Orange halos
What is the most common type of age related cataract?
Nuclear sclerotic cataract
What is the most common bacterial cause of keratitis with contact lens users?
Pseudomonas aeringosa
How does Chorioretinitis present on fundoscopy? Name a virus that causes this?
white lesions surrounded by areas of hemorrhagic necrotic areas.
Cytomegalovirus
