Ophthalmology 4 Flashcards
Name some important investigations to do into someone you suspect has cataracts:
Visual acuity test
Red reflex*
Fundoscopy
Intra-ocular pressure
- differential open angle
What are some differentials for diploia?
Orbital causes:
- Grave’s
- Trauma
- Tumour
Neuromuscular:
- Myasthenia gravis
Palsies:
- 3rd
- 4th
- 6th
What is the function of the muscles of the eye?
Medial and lateral: one function.
The rest can be remember with the pneumonic: SIN RAD, which stands for:
- Superiors - intort - Rectus - adduct
Superior Rectus: Elevates, Intorts, Adducts
Inferior Rectus: Depresses, Extorts, Adducts
Superior Oblique: Intorts, Abducts
Inferior Oblique: Extorts, Abducts
What is the most common causes of 3rd nerve palsies?
Neuropathy
- diabetes mellitus
- this will spare the pupil
Posterior communicating artery aneurysm
Tumour
Vasculitis
Demylination
What type of diplopia does 4th nerve palsy get?
Vertical
What is an improtant aspect of 6th nerve palsy?
False localising sign
- raised ICP
How is diplopia investigated?
Bloods:
- glucose
- inflammatory
Imaging:
- CT angiogram (fi suspect posterior communicating artery aneurysm)
- CT head (tumour)
Referral to neurosurgery
- posterior aneurysms can involve so important to refer
If there is a medical management for diplopia how should they be managed?
Treat underlying cause
Inform DVLA
- all patients with diplopia must inform
Prisms
Botulism injection
What are the signs on fundoscopy of retinal vein occlusion?
Vessel tortuosity
Optic disc swelling
Retinal haemorrhages
Cotton wool spots
What are the major causes of central retinal vein occlusion?
Hypertension
Hypercholesteromia
Diabetes
Smoking
Coagulative conditions
- polycythaemia
- factor V Leiden
SLE
COCP
How is a central vein occlusion investigated?
- *Blood pressure
- *Glucose
Bloods:
- FBC
- CRP
- ESR
- Coagulation screen
X-rays:
- OCT Scan
- Fluorescent angiogram
If there is suggestion of underlying pathology then: Autoimmune screen: - RF - ANCA - ANA - Anti-cardiolipin - ACE
What investigations are done into a central arterial occlusion?
Rule out GCA
Then:
Sent to TIA clinic
- CT head
- carotid doppler
Treatment:
- aspirin
- Clopidogrel
No driving for 1 month
What type of optic neuropathy does GCA cause?
Anterior Ischemic Optic Neuropathy
This specifically relates to disruption of the posterior ciliary arteries
- reduced visual acuity
- RAPD
- loss of colour vision
- disc swelling
When checking vision acuity in someone with glasses, what two ways should it be checked?
Normal Snellen chart
+
Pinholes
How can you differentiate between an ulcer and abrasion of the cornea?
Ulcer penetrates into the stroma which will turn complete green with fluorescein straining
Outline the differences in different types of corneal ulcers:
Bacteria:
- acute onset
- Painful with photophobia
- round lesion
- 7 days worth
- contact wearers
Viral:
- Insidious onset
- painful with irritation
- dendritic shape
- <7 days
Fungal
- delayed on set
- painful +photophobia
- feathery edges
What are the key symptoms of uveitis?
Red eye
Painful eye
- especially on movement
Photophobia
+/-
Visual acuity changes
What are the causes of uveitis and what are some of the longer sequalae?
Causes:
Idiopathic
Infection (TB, STIs)
Autoimmune (HLAB27)
Sequalae:
- Glaucoma
- Clouding of the cornea
- Cataracts
What is the main defect in corneal abrasions?
Epithelium
What signs may make you think there has been globe rupture?
Irregular shape to iris - iris may ruptured out
360 subconjunctiva haemorrhage
Flat Anterior chamber
Management:
- Visual assessment
- CT - if suspect foreign body
Analgesia
Antibiotics
Tetanus
What are the symptoms of a retrobulbar haemorrhage?
Pain Sub-Conjunctival Haemorrhage Reduced vision RAPD Proptosis Reduced mobility Reduced mobility
*reduced vision and movements as the blood compresses on the optic nerves
What is the complication that can occur with a sub-orbital fracture?
Trap door
- where the inferior intraocular muscles get trapped preventing eye movements
When the patient tries to move their eye they can get a reflex bradycardia
What are the main causes of a traumatic red eye?
Corneal ulcer/ abrasion
Retrobulbar Haemorrhage
Penetrating injury
Chemical injury
What are the main causes of a non-traumatic red eye?
Conjunctivitis
Uveitis
Acute angle closure glaucoma
Scleritis / episcleritis
Cellulitis
What is astigmatism?
Refractive error where there light focuses on different areas due to irregular shape of the eye
- usually described as a rugby ball shape
What is the distortion seen in ARMD?
Metamorphopsia
- blurring of straight lines
What are the major risk factors for retinal detachment?
Previous retinal detachment
Recent surgery
Myopia
- long spaced eye
Trauma
Family history
What is the first branch to come off the internal carotid?
Central retinal branch
What drug is given for GCA which is causing vision loss? and what is the underlying cause to GCA?
Methylprednisolone
*mainstay to reduce vision loss in the other eye
Underlying disease:
- Anterior Ischemic Optic Neuropathy due to disruption of the posterior ciliary arteries
What are structures which hold the lens in place - and what conditions are associated with them breaking causing dislocation?
Zonules
Marfan’s syndrome
Ehrler’s Danlos syndrome
What are the risk factors for cataracts?
Traumatic
- blunt force - think boxer
Diabetes
Steroid use
Advancing age
Congenital
What are the stages of checking vision?
Snellen
Counting fingers
Hand motions
Light and dark
What are some red flags in the history of eye examination?
Flashers/ floaters
Headache
- N&V
- Jaw/ temporal
Transient vision loss
Halos
What is the different type of chart that can be used for assessing visual acuity?
DRSET
- type of logmar
What is Fluorescein angiography?
A dye which is injected to the arm.
Passes up through the system into the eye which will give details on the vasculature of the eye.
Helps for macular degeneration, neovascularisation (as you can see where the dye does not go, where it leaks etc)
What are the risk factors for ARMD and what is the pathophysiology?
Age
Smoking
Hypertension
Family history
Patho:
build up of debris (drusen) between the choroid and retina leading to atrophy of pigmented epithelium and rods and cones
*remember only affects macula as it receives its blood supply from the choroid exclusively
What are the main investigations conducted into ARMD?
OCT
Fluorescein Angiography
Amsler’s grid
In primary open angle glaucoma what can be seen on fundoscopy? and what are your diagnostic investigations?
> 0.7 cup to disc ratio
Optic disc pallor (atrophy occurring)
Investigations:
- Automated perimetry
- Tonometry
- Gonioscopy - to assess angle
- Slit lamp examination
*over 40 should be screened annually if family history
What are the most common pathogens to cause keratitis?
Staph Aureus
Pseudomonas
What are the major complications that can occur with the eye when in ICU?
Corneal abrasion
Exposure keratopathy
Chemosis
- due to ventilation pressures
- too tight endotrachael tubing
- causes keratitis but exposing the eye
Conjunctivitis
Ischaemic optic neuropathy
- same position
- poor blood pressure
Acute Angle Glaucoma
- due lying prone
What is the diagnostic investigation into retrobulbar haemorrhage? Management?
CT Scan of orbits
Canthotomy/ canthyolysis
What is the normal pressure in the anterior chamber?
10-21mmHg
What are the diagnostic investigations into primary open angle glaucoma?
Goldmann Application tonometry
Visual field testing
- perimetry
Fundoscopy
- optic disc to cup size >0.5 is abnormal
What is the management of open angle glaucoma?
Latanoprost
- side effects include eye lash elongation
- eyelid pigmentation and iris pigmentation
- increases outflow
Timolol
- reduce production
Dorzolamide
- carbonic anhydrase inhibitor
Surgical:
- trabeculectomy
- creates a small plebe
Outline the pathophysiology of diabetic retinopathy, how likely is to to cause blindness? and how is it treated?
Basement membrane dysfunction which initially causes leaks and aneurysms (Dots)
These can the leak (blots)
The fluid leaked is reabsorbed and leaves behind debris (hard exudates)
Eventually the basement membrane pericytes close up causing ischemia and micro-infarcts (cotton wool spots)
- this then triggers VEGF release
The mixture of fluid from new vessels and aneurysms accumulates in the macula causing macula oedema
Treatment:
- control of BP and glucose
- pan-retinal photocoagulation
- Anti- VEGF
What are some of the factors which can make diabetic retinopathy worse?
Smoking Poor glycaemic control Smoking Pregnancy Failing to comply with annual check up
What are in the investigations done into diabetic retinopathy?
Photographs of fundus
OCT (source macular oedema)
Fluorescein angiography (source leakage)
Outline tests done into open angle glaucoma:
Applanation tonometry
Slit lamp examination
- check cup to disc ratio
Automated perimetry visual assessment
Measurement of corneal thickness
Gonioscopy measurement
What are the complications of diabetic retinopathy?
Retinal detachment
Vitreous haemorrhage
Optic neuropathy
Cataracts
