3C Ophthalmology Flashcards
(31 cards)
What is the third cranial nerve?
What is it’s motor effect?
How is it tested?
Look for (3)
Ask about (1)
Oculomotor nerve
Medial eye movement
Test - eye movements. see below.
Test (do CN III, IV and VI together) - Ask the patient to follow your finger with their eyes while you slowly draw out the shape of two H’s joined in the middle. You should ensure that the vertical movements are at extremes of lateral gaze as well as in the midline.
- Look for nystagmus, ptosis, miosis
- Ask about double vision
_______________________ - Look for inability to move the eye (ophthalmoplegia)
- Look for nystagmus (involuntary rhythmic eye oscillation)
- Assess conjugate gaze(the ability of the eyes to work in unison)
- Check for ptosis and miosis (constricted pupil, parasympathetic component of CNIII)
Name the muscles in this diagram and which nerve innervates them (this is a right eye)
.
What is the second cranial nerve?
What is it’s effect?
Steps to examining this nerve?
Name 3 examples of problems you could detect?
CN II = Optic nerve.
This is a sensory nerve only, no motor effect.
Examination of eyes
- Look at eyes
- Look at back of eyes (ophthalmoscope)
- Visual acuity (snellen chart)
- Visual fields
- Pupillary reflexes
- Swinging light test to check RAPD (relative afferent pupillary defect)
Problems detected
- Papillodema (from fundoscopy) can be caused by raised ICP
- Horner syndrome
- Ptosis - drooping of upper eyelid
- Miosis - constricted pupil
Photo - cupping
What is the name of cranial nerve III?
What are the signs of a third cranial nerve palsy?
Name three possible causes?
What eye muscles does CNIII innervate?
Oculomotor nerve
Signs
- Down & out eye
- Ptosis
- Dilated/blown pupil, if parasympathetic pathway disrupted
Causes
- Vasculopathic (most common) ie. diabetes or hypertension
- tumour
- aneurysm
Muscles - all except superior oblique and lateral rectus
(so superior rectus, inferior rectus, medial rectus, inferior oblique, elevator palpebral superioris - elevates upper eyelid)
What is the name of cranial nerve VI?
What are the signs of a sixth cranial nerve palsy?
Name three possible causes?
What eye muscles does CNVI innervate?
Abducens nerve
Signs
- crossed eye (looks medially)
Causes
- Vasculopathic (ie diabetes or hypertension)
- Tumour
- Raised intercranial pressure
Muscle - lateral rectus
What is the name of cranial nerve IV?
What are the signs of a fourth cranial nerve palsy?
Name four possible causes?
What eye muscles does CNVI innervate?
Trochlear nerve
Signs - nasal upshoot (eye looks to medial upper corner when trying to look medially).
Causes
- Vasculopathic (ie diabetes or hypertension)
- Tumour
- Congenital
- Trauma (long skinny nerve that gets damaged easily)
Muscle - superior oblique
Defect in this area causes what visual defect?
1. Optic nerve
2. Optic chiasm
3. Optic tract
- Monocular visual loss (one whole eye)
- Bitemporal hemianopia
- Homonymous hemianopia
Name the parts of the visual pathway
What are the names of the cranial nerves?
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Vestibulocochlear
- Glossopharyngeal
- Vagus
- Accessory
- Hypoglossal
Ooh, ooh, ooh to touch and feel very good velvet. Ah, heaven!
On, On, On, They Traveled And Found Voldemort Guarding Very Ancient Horcruxes
AMD stands for?
Demographic?
Symptom?
Examination findings
Age-related macular degeneration
Older people over 60
Gradual loss of central vision
Distorted lines on Amsler grid
AMD is caused by damage to the blood vessels that supply the macula. This change also harms the macula.
There are two types of AMD:
Dry AMD occurs when the blood vessels under the macula become thin and brittle. Small yellow deposits, called drusen, form. Almost all people with macular degeneration start with the dry form.
Wet AMD occurs in about 10% of people with macular degeneration. New abnormal and very fragile blood vessels grow under the macula. These vessels leak blood and fluid. This type of AMD causes most of the vision loss associated with the condition.
Normal intraocular pressure?
Normal intraocular pressure is 10-21 mmHg. Raised intraocular pressure is due to impaired drainage of aqueous fluid within the eye.
Does glaucoma affect central or peripheral vision?
Other signs on fundoscopy?
Peripheral
POAG (primary open angle glaucoma) may present insidiously and for this reason is often detected during routine optometry appointments. Features may include:
-peripheral visual field loss - nasal scotomas progressing to ‘tunnel vision’
-decreased visual acuity
-optic disc cupping
-Pale optic disk
What does RAPD stand for
Where is the lesion
Name two conditions you’d see a positive RAPD in?
Relative afferent pupillary defect
Also known as the Marcus-Gunn pupil, a relative afferent pupillary defect is found by the ‘swinging light test’. It is caused by a lesion anterior to the optic chiasm i.e. OPTIC NERVE or RETINA
Finding
the affected and normal eye appears to dilate when light is shone on the affected
Causes
retina: detachment
optic nerve: optic neuritis e.g. multiple sclerosis
Pathway of pupillary light reflex
afferent: retina → optic nerve → lateral geniculate body → midbrain
efferent: Edinger-Westphal nucleus (midbrain) → oculomotor nerve
Treatments for eye conditions
1. Scleritis?
2. Wet AMD?
3. Amaurosis fugax?
4. Optic neuritis?
- Oral Steroids. immunosuppressive agents eg. cyclophosphamide, azathioprine.
- Anti VEG-F. Laser photocoagulation second choice due to risk fo acute vision loss after treatment.
- Aspirin
- High dose steroids
Signs of glaucoma on fundoscopy?
What changes to the vision do you get?
- Closed angle
- open angle
Cupping (increased cup to disc ratio) - because of increased intra-ocular pressure
Decreased peripheral vision.
Closed Angle - painful eye, halos
Open angle - often asymptomatic
Glaucoma is an optic neuropathy in which there is visual field loss. Two main types include closed-angle and open-angle glaucoma. These are defined by the presence of ocular hypertension (increased pressure in the eye) which compresses on the optic nerve. Whilst causes are usually primary in origin, these glaucoma types may also be due to trauma, uveitis or steroids.
Closed-angle glaucoma: The angle between the iris and cornea narrows, abruptly blocking the trabecular meshwork which drains aqueous humour from the anterior chamber of the eyeball. This results in sudden ocular hypertension, and as such there is a rapid onset of symptoms including a painful red eye, impaired vision and halos around lights. Often the pressure will result in a fixed, dilated pupil that is minimally responsive to light and cupping of the optic disc.
Open-angle glaucoma: This is the most common cause of glaucoma. The trabecular meshwork becomes blocked over time due to risk factors such as age, ethnicity and myopia. This results in a progressive ocular hypertension and is mostly asymptomatic. Over time there may be a peripheral visual field loss and on examination you may see cupping of the optic disc.
There is also a third type of glaucoma called normal- or low-tension glaucoma. Low vascular perfusion of the optic nerve makes it more susceptible to the normal pressures of the eye leading to damage of the nerve. The presentation is similar to that of traditional open-angle glaucoma.
What are the signs of diabetic retinopathy on fundoscopy?
Signs of retinal artery occlusion on fundoscopy?
Retinal vein occlusion?
CRAO central retinal artery occlusion - pale retina, cherry red spot
CRVO central retiunal vein occlusion (CRVO = painless) - flame haemorrhages, stormy sunset (painless loss of vision). Also macula oedema, cotton wool spots, disc swelling, RAPD.
In what condition do you see Drusen? What are they?
Risk factors for this illness
Treatment
Age related macular degeneration.
Yellow deposits of cellular waste material under the retina.
Risk factors - age, family history, smoking.
Treatment - no specific treatment. Monitoring, lifestyle: stop smoking, reduce cholesterol, healthy diet and take vitamin supplements eg. Vitamins A, C & E (prevents Dry AMD turning to wet AMD).
Also known as atrophic macular degeneration, this is the most common type. As many as 90% of all cases of macular degeneration fall under this category.
Dry macular degeneration results from a thinning or breaking down of the macula, usually as a result of the build-up of tiny yellow deposits of cellular waste material, called drusen, under the retina.
This build-up of drusen eventually impacts the functioning of the macula leaving a blurry or blind spot in the center of a person’s vision, making everyday activities such as driving and recognizing faces difficult or impossible.
Differences between benign and malignant eyelid lesions?
Describing an eye lesion - what should you say?
Location
Size
Appearance
Any eye problems
Steps to a fundoscopy OSCE station?
https://simpleosce.com/examinations/other/fundoscopy.php
What eye conditions can cause a PAINFUL loss of vision? (name 3)
vs PAINLESS? (name 3)
Painful loss of vision
- Endophthalmitis
- Anterior uveitis
- Keratitis
- Acute angle closure glaucoma
- Optic neuritis (painful eye movements)
- papilloedema
PainLESS loss of vision
- Retinal detachment
- Diabetic retinopathy
- Retinal artery occlusion (central or branch) - transient RAO is amaurosis fugax
- Retinal vein occlusion (central or branch)
- Stroke
- Cataracts
- Vitreous detachment / haemorrhage
Can be either
- Temporal arteritis
Treatment for conditions that affect vision
1.Temporal arteritis
2. Optic neuritis
3. Retinal detachment
4. Retinal vein occlusion
5. Retinal artery occlusion
6. Endophthalmitis
7. Acute angle closure glaucoma
- High dose IV Steroids, when vision affected
- High dose IV Steroids
- Urgent ophthalmology review
- Conservative treatment, usually
- No treatment really except firm ocular massage if presents within 90 mins of loss of vision
- Intravitreal vancomycin (usual cause - gram positive bacteria)
- IV acetazolamide. Beta blockers. Pilocarpine (to constrict pupil and open angles). Peripheral iridotomy.
Acetazolamide is a carbonic anhydrase inhibitor - acts like a diuretic reducing fluid in the eye.
Causes of a hypopyon?
Endophthalmitis (hypopyon, cloudy cornea, redness)
Anterior uveitis
