12 - Ophthalmology Conditions 2 Flashcards
What are some causes of optic neuritis?
- MS
- Infection e.g syphillis
- Drugs e.g ethambutol, methanol
- Diabetes
- Vitamin deficiency
What are some risk factors for developing optic neuritis?
- Age 20-40
- Female
- Caucasian
- FHx of MS
How does optic neuritis present?
- Unilateral loss of vision over hours or days
- Dyschromatopsia/Red desaturation
- Eye movements painful
- Flashing lights
- RAPD
What is the prognosis with optic neuritis?
- Usually resolves in 2-6 weeks
- 50-80% go on to develop MS in next 15 years
What is the treatment for optic neuritis?
- High dose methylprednisolone IV for 72hrs
then
- PO Prednisolone for 11 days
What is the difference between orbital and periorbital cellulitis?
(IMAGE IMPORTANT)
Orbital: Infection of the tissues posterior to the septum and it is life threatening so an emergency. Usually from paranasal sinus, dental or occular infection
Periorbital: Infection of the tissues anterior to the septum. Usually from sinus infections or facial skin lesions
What is the presentation of periorbital cellulitis and how can you rule out orbital cellulitis?
- Swollen red hot eyelids
- Features that rule out orbital: absence of painful eye movements, absence of visual impairment, absence of diplopia
- If in doubt treat as orbital cellulitis as this is life threatening
What is the treatment of periorbital cellulitis?
- PO co-amoxiclav
- Admit if child or high risk of progression to orbital cellulitis
- Safety net to return if any red flags or not responding after 48 hours
How does orbital cellulitis present?
- Swollen red eye
- Pain on eye movement and reduced eye movements
- Diplopia
- Proptosis
- RAPD
- Fever
- Reduced visual acuity
What are the complications with orbital cellulitis that make it an emergency?
- Subperiosteal and orbital abscess
- Visual loss due to optic neuritis and CRAO
- Meningitis
- Brain abscess
- Cavernous sinus thrombosis
When should you CT in orbital cellulitis and what are some red flags that an orbital cellulitis needs urgent action?
Eyelid oedema and erythema OR failure to respond to 48hr abx PLUS ONE RED FLAG:
- Proptosis
- Chemosis (swelling ov conjunctiva)
- Ophthalmoplegia
- Relative afferent pupillary defect (RAPD)
- Systemically unwell 6. Painful eye movement
- Altered visual acuity
How is orbital cellulitis managed?
- Admit for promt CT (if indicated as radiation exposure to young), ENT and Optho assessment
- IV Abx (Ceftriaxone +/- Metronidazole if sinus infection)
- Surgical drainage of any abscesses to prevent meningeal involvement and cavernous sinus thrombosis
How can you tell the difference between episcleritis and scleritis?
Episclera lies superficially so the vessels will move when probed with a cotton bud and blanch when 10% phenylephrine is put on them
This won’t happen with sclerla vessels as they are deeper
How does episcleritis present?
- Typically not painful but can be mild pain
- Segmental redness (rather than diffuse) in lateral sclera
- Foreign body sensation
- Dilated episcleral vessels
- Watering of eye
- No discharge
What types of patients does episcleritis usually present in?
MOSTLY IDIOPATHIC
- Young middle aged women
- Inflammatory disorders e.g IBD, RA
How is episcleritis managed?
- Self limiting in 1-4 weeks
- Symptomatic relief with simple analgesia, cold compresses, artificial tears
- Safety net
What is scleritis and why is it more serious than episcleritis?
- Generalised inflammation of the sclera with oedema of the conjunctiva
scleral thinning, and vasculitic changes
- URGENT REFERRAL as necrotising scleritis can lead to perforation of the sclera and is sight threatening
What are the causes of scleritis?
Usually not infectious, it is autoimmune related
How does scleritis present?
- Diffuse red eye
- Severe dull pain made worse on occular movements
- Headache
- Photophobia
- Reduced visual acuity
How is scleritis managed?
URGENT OPHTHO REFERRAL
Anterior/Non-necrotising:
- Oral high-dose prednisolone
- Oral NSAIDs
Posterior or Necrotising:
- Immunosuppression for underlying autoimmune condition e.g clophosphamide or rituximab
- Course of methylprednisolone
- If globe perforation need surgery
How can you detect a cataracts with a pen torch?
COME BACK TO
What are indications of cataract surgery and what can you expect to change with your vision from it?
Indications: Symptoms are troubling, lifestyle is restricted, or if unable to read a number-plate at 20 metres (and they need to drive)
Changes:
- Improve colour vision
- Dazzle/glare often remains after
- Improved visual acuity as put refractive lens in, may need distance glasses
- Visual acuity may not return to normal as may be underlying co-existing AMD
What are Drusen in AMD?
- Soft Drusen lift RPE from Bruch’s membrane. This can cause VEGF release so encourages neovascularisation and progression from dry to wet AMD
How does neovascularisation in wet AMD cause vision loss?
- Disciform scar in macula that leads to a blind spot (scotoma)
What is Charles Bonnet synrome?
Most people with AMD may experience this
Vivid hallucinations in response to central vision loss
Reassure them it is normal
What is the pathophysiology of retinal detachment and why is it an emergency?
Retins separates from the choroid, usually due to a tear allow vitreous humour to get under retina.
Sight threatening as outer retina gets its blood supply from choroid
Rhegmatogenous retinal detachment—tear in retina causes fluid to pass
from vitreous space to subretinal space between sensory retina and
the retinal pigment epithelium. Caused by trauma
Exudative retinal detachment - Retina detaches without
a tear, eg hypertension, vasculitis, macular degenerative conditions, tumour
Tractional retinal detachment—pulling on the retina, eg proliferative reti- napathy, myopic eyes
What are some of the risk factors for retinal detachment?
- Posterior vitreous detachment
- Diabetic retinopathy
- Trauma to the eye
- Retinal malignancy
- Older age
- Family history
- Myopia
- Cataract surgery (vitreous haemorraghe)
If a retinal tear is found before retinal detachment, what can you do to prevent this from developing into retinal detachment?
Cryotherapy or Laser Retinopexy
Creates adhesions between the retina and the choroid
How does a retinal detachment present?
4 F’s!!!
- Flashes
- Floaters
- Field loss (usually peripheral)
- Fall in acuity (painless vision loss like a curtain or shadow over vision)
How does retinal detachment look on fundoscopy?
- Grey opalescent retina ballooning forward
- May see tear
- Crinkling of retinal tissue
How is retinal detachment managed?
- URGENT REFERRAL AND MANAGEMENT
- Cryotherapy or laser coagulation to seal any tear
- REST! Lie flat if superior tear, lie head 30 degrees up in inferior tear
- Surgery to reattach retina: vitrectomy, scleral bulking, pneumatic retinopexy
What is posterior vitreous detachment and what is it caused by?
Vitreous body keeps retina pressed against the choroid. It is made of collagen and water
As we age it becomes less firm so the posterior vitreous may no longer sit on the retina
Normal part of ageing
How does posterior vitreous detachment present?
- Often asymptomatic
- Painless spots of vision loss
- Floaters
- Flashing lights
No decline in vision or loss of visual fields
What is a vitreous haemorraghe and what is it caused by?
Bleeding into the vitreous body
- Retinal neovascularisation (DM, CRVO)
- Retinal tears
- Retinal detachment
- Trauma
How does vitreous haemorraghe present and how is it managed?
Presentation
- Patient will see black floaters or ring like floaters with clear centre
Patients typically present with an acute or subacute onset of: - painless visual loss or haze (commonest)
- red hue in the vision
- floaters or shadows/dark spots in the vision
Mx
- If small may undergo spontaneous reabsorption
- If dense then do vitrectomy to remove blood
- Give anti-VEGF if neovascularisation or photocoagulation for diabetic retinopathy
Signs:
- decreased visual acuity: variable depending on the location, size and degree of vitreous haemorrhage
- visual field defect if severe haemorrhage
What is this and what could have caused it?
Subconjunctival Haemorraghe
One of the vessels in the conjunctiva has popped and blood pooled between sclera and choroid. It is painless
Causes: heavy coughing, weight lifting, straining when constipated, trauma
How is a subconjunctival haemorraghe managed?
- Resolve spontaneously in 2 weeks
- Can give lubricating eye drops if foreign body sensation
- Consider underlying disorders e.g HTN
What is retinitis pigmentosa?
Inherited condition of the retina (X-Linked, Auto Dom or Auto Rec) usually affecting males
Degeneration of the rod photoreceptors followed by degeneration of the cones
Can be associated with other systemic diseases e.g Usher Syndrome, Refsum syndrome
How does retinitis pigmentosa present and what does it look like on fundoscopy?
Presentation
- Starts with night blindness as rods affected
- Then progresses to peripheral vision loss then central vision loss
- Eventually causes complete blindness
Fundoscopy
- Bone spicule pigmentation especially in mid-peripheries
- Can have pale optic disc
- Narrowing of arterioles
How is retinitis pigmentosa managed?
Nothing to slow the progress of the disease just manage it
How does a corneal abrasion present?
- History of contact lenses or foreign body
- Painful red eye
- Foreign body sensation
- Watering eye
- Blurring vision
- Photophobia
How is a corneal abrasion diagnosed?
- Fluorescein stain and blue light slit lamp exam: will collect in the area of abrasion
- Evert eye lid to look for foreign body
What is a corneal ulcer and what are some of the causes of this?
- White opaque structure on the cornea.
- Fx: Can be very painful, red eye, photophobia, blurred vision
- A corneal ulcer describes a defect in the cornea, typically secondary to an infective cause.
- RFs: contact lense use, Vit A deficiency
- Causes: infection (keratitis: bacterial viral, fungal), trauma, contact lens wear, vasculitis from RA
How is a corneal ulcer managed?
- Refer to specialist urgently for urgent diagnostic smear/Gram stain and scrape
- Remove contacts
- Prescribe aciclovir if opthalmic shingles or herpes keratitis
- Alternate chloramphenicol drops (for Gram +ve) with ofloxacin drops (for Gram –ve) until cultures known
- Once recovery started can add steroid drops
Why do you need to be careful when using steroid eye drops?
- Risk of glaucoma
- Risk of cataract formation
- Risk of corneal melt if ulcer
- Can prolong viral conjunctivitis
What is thyroid eye disease and what is the main risk factor?
In people with Grave’s disease and doesn’t correlate with whether euthryoid, hyperthyroid or hypothyroid
Smoking is biggest risk factor
Avoid radioiodine treatment as can worsen it. Causes retrooribtal inflammation and lymphocyte infiltration
What are some of the signs and symptoms of thyroid eye disease?
Symptoms
- Eye discomfort
- Grittiness
- Diplopia
- Photophobia
- Decreased visual acuity
- RAPD
Signs
- Exopthalmos
- Proptosis (look from above)
- Corneal ulceration
- Papilloedema
- Loss of volour vision
- Opthalmoplegia especially on upward gaze
How is thyroid eye disease diagnosed?
- Clinical
- Do CT or MRI of orbits and will see enlarged eye muscles
How is thyroid eye disease managed?
- Treat hyper/hypothyroidism
- Stop smoking
- Avoid radioiodine
- Symptomatic: artificial tears, sunglasses, avoid dust, elevate bed when sleeping to prevent periorbital oedema, eyelid surgery
- Diplopia: Fresnl prism stuck to glasses
- Opthalmoplegia or Oedema: high dose steroids and oral radiotherapy
- Sigh threatening: surgical decompression
What nerves cause pupil dilation and pupil constriction?
What are some disorders that cause an abnormal pupil shape?
Anterior uveitis: scarring posterior synechiae
Rubeosis iridis: neovascularisation in iris due to diabetic retinopathy
Coloboma: congenital
Tadpole pupil: temporary, associated with migraines
Acute angle closure glaucoma: oval pupil
Trauma to sphincter muscles: from cararact surgery
What are some causes of mydriasis (dilated pupil)?
- Third nerve palsy
- Holmes-Adie syndrome: usually women with tonic pupil, absent knee/ankle jerks and impaired sweating
- Raised intracranial pressure: uncal herniation
- Congenital
- Trauma
- Stimulants such as cocaine
- Anticholinergics
What are some causes of miosis (constricted pupil)?
- Horners syndrome
- Cluster headaches
- Argyll-Robertson pupil (in neurosyphilis)
- Opiates
- Nicotine
- Pilocarpine
How does a third nerve palsy present?
Occulomotor
- Ptosis
- Dilated non-reactive pupil
- Divergent strabismus: “down and out”
What are some causes of a third nerve palsy?
Can be idiopathic
Pupil Sparing (microvascular cause as no compression of parasympathetic fibres)
Diabetes
Hypertension
Ischaemia
Full Palsy
Idiopathic
Tumour
Trauma
Cavernous sinus thrombosis
Posterior communicating artery aneurysm
Raised intracranial pressure
What are some causes of Horner’s syndrome? (disruption of sympathetic fibres)
4 Ss, 4 Ts, 4Cs + Congenital (Heterochromia)
Can tell location by the pattern of anhidrosis
Central lesions cause anhidrosis of the arm and trunk as well as the face. Pre-ganglionic lesions cause anhidrosis of the face. Post-ganglionic lesions do not cause anhidrosis
How is Horner’s syndrome diagnosed?
- Cocaine eye drops (stop noradrenaline reuptake)
- Adrenaline eye drops (dilates pupil)
What is Holmes-Adie Pupil?
- Damage to post-ganglionic PS fibres due to virus
- Unilateral dilated pupil that is slow to react to light with slow dilation of the pupil following constriction
- Over time pupil will get smaller
Holmes Adie Syndrome: Holmes Adie pupil with absent ankle and knee reflexes
What is a Argyll-Robertson Pupil?
- Found in neurosyphillis and diabetes. (Prostitute Pupil - Accomodates but does not react)
- Constricted pupil that accommodates when focusing on a near object but does not react to light.
- They are often irregularly shaped
Why should you be concerned if somebody presents with a unilateral third nerve palsy?
Posterior Communicating Artery Aneurysm until proven otherwise
Need to send for CT angiography as high risk of rupture
Will involve pupil but doesn’t necessarily have down and out
What are some causes of a RAPD?
Do swinging light test
How does internuclear opthalmoplegia present?
(IMPORTANT IMAGE)
- Weakness of aDduction of the affected eye
AND
- Horizontal jerk nystagmus of aBducting other eye
Due to lesion in MLF that connects the 3rd and 6th cranial nerves. MS
What are some signs of hypertensive retinopathy?
- Silver/Copper wiring: walls of the arterioles become thickened and sclerosed causing increased reflection of the light
- Arteriovenous nipping: arterioles cause compression of the veins where they cross due to sclerosis and hardening of the arterioles
- Cotton wool spots: ischaemia and infarction in the retina causing damage to nerve fibres.
- Hard exudates: damaged vessels leaking lipids into the retina
- Retinal haemorrhages: damaged vessels rupturing and releasing blood into the retina.
- Papilloedema: ischaemia to the optic nerve resulting in optic nerve swelling (oedema) and blurring of the disc margins
How is hypertensive retinopathy graded?
Keith-Wagener Classification
Stage 1: Mild narrowing of the arterioles
Stage 2: Focal constriction of blood vessels and AV nicking
Stage 3: Cotton-wool patches, exudates and haemorrhages
Stage 4: Papilloedema
What are the complications with hypertensive retinopathy?
- At risk of developing retinal pathology
- Increased CVD and stroke risk
How is hypertensive retinopathy managed?
- Controlling the blood pressure e.g antihypertensives, less salt
- Reduce risk factors such as smoking and blood lipid levels
When a patient has visual field loss, what questions do you need to ask yourself to work out the location of the lesion?
What visual field defects would you get with the following lesions?
(Important concept card)
Optic nerve: total blindness of that eye. Direct pupillary reflex is absent, indirect remains intact. Lesions tend to occur in the horizontal meridian when in the optic nerve. When the lesions are behind the optic chiasma, the boundaries are in the vertical meridian. Acuity tends to be affected .
Optic chiasma: Bitemporal hemianopia. Fibres coming from the nasal halves of both retinas are involved. There is normal direct, consensual light reflex and accommodation reflex
Optic tracts A lesion on the optic tract causes a contralateral homonymous hemianopia. There is a normal direct light reflex, consensual light reflex and accommodation reflex.
Optic radiation: contralateral homonymous hemianopia. Lesions over the lateral portions of the lateral geniculate body which received impulses from the inferior rental quadrants (superior visual field). Lesions in the nerve fibres passing more directly posterior to the cortex cause an inferior quadrantic hemianopia.
Visual cortex Destruction of the the primary visual cortex produces contralateral homonymous hemianopia. Macula is often spared because in some people there is an anastomosis between the posterior and middle cerebral arteries.
If somebody has a homonymous hemianopia with macular sparing, what is the location of the lesion?
- Occipital Lobe Visual Cortex
- Means they have likely had a PCA stroke
- Both MCA and PCA supply the macula so if PCA knocked out MCA can compensate. All other parts of visual cortex only supplied by MCA
