Ophthalmology 2 Flashcards
what is episcleritis?
Episcleritis is benign and self limiting inflammation of the episclera, the outermost layer of the sclera. The episclera is situated just underneath the conjunctiva.
It is relatively common in young and middle aged adults and is not usually caused by infection. It is often associated with inflammatory disorders such as rheumatoid arthritis and inflammatory bowel disease.
phenylephrine - used to distinguish between epscleriitis ans scleritis
how does episcleritis present?
Episcleritis usually presents with acute onset unilateral symptoms:
- Typically not painful but there can be mild pain
- Segmental redness (rather than diffuse). - There is usually a patch of redness in the lateral sclera.
- Foreign body sensation
- Dilated episcleral vessels
- Watering of eye
- No discharge
how is episcleritis managed?
If in doubt about the diagnosis, refer to ophthalmology.
Episcleritis is usually self limiting and will recover in 1-4 weeks. In mild cases no treatment is necessary. Lubricating eye drops can help symptoms.
Simple analgesia, cold compresses and safetynet advice are appropriate.
More severe cases may benefit from systemic NSAIDs (e.g. naproxen) or topical steroid eye drops.
what is scleritis?
Scleritis involves inflammation of the full thickness of the sclera. This is more serious than episcleritis. It is not usually caused by infection.
what is the most serious type of scleritis?
The most severe type of scleritis is called necrotising scleritis. Most patients with necrotising scleritis have visual impairment but may not have pain. It can lead to perforation of the sclera. This is the most significant complication of scleritis.
what conditions are associated with scleritis?
There is an associated systemic condition in around 50% of patients presenting with scleritis. This may be:
Rheumatoid arthritis Systemic lupus erythematosus Inflammatory bowel disease Sarcoidosis Granulomatosis with polyangiitis
how does scleritis present?
Scleritis usually presents with an acute onset of symptoms. Around 50% of cases are bilateral.
Severe pain Pain with eye movement Photophobia Eye watering Reduced visual acuity Abnormal pupil reaction to light Tenderness to palpation of the eye
how is scleritis managed?
NICE Clinical Knowledge Summaries on red eye say patients with potentially sight threatening causes of red eye should be referred for same day assessment by an ophthalmologist.
Management in secondary care involves:
Consider an underlying systemic condition
NSAIDS (topical / systemic)
Steroids (topical / systemic)
Immunosuppression appropriate to the underlying systemic condition (e.g. methotrexate in rheumatoid arthritis)
what are corneal abrasions?
Corneal abrasions are scratches or damage to the cornea. They are a cause of red, painful eye
what can cause corneal abrasions?
Contact lenses Foreign bodies Finger nails Eyelashes Entropion (inward turning eyelid) If the abrasion is associated with the use of contact lenses there may be infection with pseudomonas.
what is an important differential to corneal abrasion?
An important differential diagnosis to consider is herpes keratitis as this will require treatment with antiviral eye drops.
how do corneal abrasions present?
History of contact lenses or foreign body Painful red eye Foreign body sensation Watering eye Blurring vision Photophobia
how are corneal abrasions diagnosed?
A fluorescein stain is applied to the eye to diagnose a corneal abrasion. This is a yellow-orange colour. The stain collects in abrasions or ulcers, highlighting them.
Slit lamp examination may be used in more significant abrasions.
how are corneal abrasions managed?
Management in secondary care:
Simple analgesia (e.g. paracetamol)
Lubricating eye drops can improve symptoms
Antibiotic eye drops (i.e. chloramphenicol)
Bring the patient back after 1 week to check it has healed
Cyclopentolate eye drops dilate the pupil and improve significant symptoms, particularly photophobia. These are not usually necessary.
Uncomplicated corneal abrasions usually heal over 2-3 days.
what is keratitis?
Keratitis is inflammation of the cornea.
what can cause keratitis?
Viral infection with herpes simplex
Bacterial infection with pseudomonas or staphylococcus
Fungal infection with candida or aspergillus
Contact lens acute red eye (CLARE)
Exposure keratitis is caused by inadequate eyelid coverage (e.g. eyelid ectropion)
what is the most common cause of keratitis?
Herpes simplex infection is the most common cause of keratitis. This is called herpes simplex keratitis. It can cause inflammation in any part of the eye however it most commonly affects the epithelial layer of the cornea. Herpes simplex keratitis can be primary or recurrent.
Herpes keratitis usually affects only the epithelial layer of the cornea. If there is inflammation of the stroma (the layer between the epithelium and endothelium), this is called stromal keratitis. This is associated with complications such as stromal necrosis, vascularisation and scarring and can lead to corneal blindness.
how does herpes keratitis present?
Painful red eye Photophobia Vesicles around the eye Foreign body sensation Watering eye Reduced visual acuity. This can vary from subtle to significant.
how is herpes keratitis diagnosed?
Staining with fluorescein will show a dendritic corneal ulcer. Dendritic describes the appearance of branching and spreading of the ulcer.
Slit lamp examination is required to find and diagnose keratitis.
Corneal swabs or scrapings can be used to isolate the virus using a viral culture or PCR.
how is herpes keratitis managed?
NICE Clinical Knowledge Summaries on red eye say patients with potentially sight threatening causes of red eye should be referred for same day assessment by an ophthalmologist.
Management options in secondary care:
Aciclovir (topical or oral)
Ganciclovir eye gel
Topical steroids may be used alongside antivirals to treat stromal keratitis
Corneal transplant may be required after the infection has resolved to treat corneal scarring caused by stromal keratitis.
what is subconjunctival haemorrhage?
Subconjunctival haemorrhages are a relatively common condition where one of the small blood vessels within the conjunctiva ruptures and release blood into the space between the sclera and the conjunctiva. They often appear after episodes of strenuous activity such as heavy coughing, weight lifting or straining when constipated. It can also be caused by trauma to the eye.
what conditions can predispose to developing subconjunctival haemorrhage?
Hypertension
Bleeding disorders (e.g thrombocytopenia)
Whooping cough
Medications (warfarin, NOACs, antiplatelets)
Non-accidental injury
*it is often idiopathic and happens in patients that are otherwise healthy
how does a subconjunctival haemorrhage present?
A subconjunctival haemorrhage appears as a patch of bright red blood underneath the conjunctiva and in front of the sclera covering the white of the eye. It is painless and does not affect vision.
There may be a history of a precipitating event such as a coughing fit or heavy lifting.
They can be confidently diagnosed based on a simple history and examination.
how is subconjunctival haemorrhage managed?
Subconjunctival haemorrhages are harmless and will resolve spontaneously without any treatment. This usually takes around 2 weeks.
Think about the possible causes such as hypertension and bleeding disorders. These may need investigating further.
If there is a foreign body sensation lubricating eye drops can help with symptoms.
what is retinal vein occlusions?
it occurs when a blood clot (thrombus) forms in the retinal veins and blocks the drainage of blood from the retinal - the central vein runs through the optic berve and is responsible for draining blood from the retina
There are 4 branched veins that come together to for the central vein - Blockage of one of the branch veins causes problems in the area drained by that branch whereas blockage in the central vein causes problems with the whole retina.
how does retinal vein occlusion present?
sudden painless loss of vision usually unilateral
Blockage of a retinal vein causes pooling of blood in the retina. This results in leakage of fluid and blood causing macular oedema and retinal haemorrhages. This results in damage to the tissue in the retina and loss of vision. It also leads to the release of VEGF, which stimulates the development of new blood vessels (neovascularisation).
what are this risk factors for retinal vein occlusion?
Hypertension High cholesterol Diabetes Smoking Glaucoma Systemic inflammatory conditions such as systemic lupus erythematosus
what tests would you perform for retinal vein occlusion?
Fundoscopy (flame and blot haemorrhages, optic oedema, macula oedema)
Fluorescein angiogram
also perform investigations to rule out causes - BP, ESR, serum glucose
how is retinal vein occlusion managed?
- ophthalmology referral and assessment immediately
management aims to treat macular oedema and prevent complications such as neovascularisation of the retina and iris and glaucoma. The options are:
laser photocoagulation
intravitreal steroids (e.g. a dexamethasone intravitreal implant)
anti-VEGF therapies (ranibizumab)
what is central retinal artery occlusion?
Central retinal artery occlusion occurs where something blocks the flow of blood through the central retinal artery. The central retinal artery supplies the blood to the retina. It is a branch of the ophthalmic artery, which is a branch of the internal carotid artery.
The most common cause of occlusion of the retinal artery is atherosclerosis causing a thromboembolism. It can also be caused by giant cell arteritis, where vasculitis affecting the ophthalmic or central retinal artery causes reduced blood flow.
what are the risk factors for retinal artery occlusion?
same as for other CV disease Older age Family history Smoking Alcohol consumption Hypertension Diabetes Poor diet Inactivity Obesity
how does retinal artery occlusion present?
sudden painless loss of vision
there will be relative afferent pupillary defect - his is where the pupil in the affected eye constricts more when light is shone in the other eye compared when it is shone in the affected eye. This occurs because the input is not being sensed by the ischaemic retina when testing the direct light reflex but is being sensed by the normal retina during the consensual light reflex.
what would fundoscopy show in retinal artery occlusion?
Fundoscopy will show a pale retinal with a cherry red spot. The retina is pale due to a lack of perfusion with blood. The cherry red spot is the macula, which has a thinner surface that shows the red coloured choroid below and contrasts with the pale retina.
how is retinal artery occlusion managed?
immediate referral to ophthalmologist for assessment and management
Giant cell arteritis is an important potentially reversible cause. Therefore older patients are tested and treated for this if suspected. Testing involves an ESR and temporal artery biopsy and treatment is with high dose steroids (i.e. prednisolone 60mg).
If the patient presents shortly after symptoms develop then there are certain things that can be tried to attempt and dislodge the thrombus. None of these have a strong evidence base. Some examples are:
Ocular massage
Removing fluid from the anterior chamber to reduce intraocular pressure.
Inhaling carbogen (a mixture of 5% carbon dioxide and 95% oxygen) to dilate the artery
Sublingual isosorbide dinitrate to dilate the artery
Long term management involves managing CV risk factors
what is retinitis pigmentosa
Retinitis pigmentosa is a congenital inherited condition where there is degeneration of the rods and cones in the retina. There are many different genetic causes. Some causes involve isolated retinitis pigmentosa whereas others result in systemic diseases associated with the condition. They vary in age at presentation and prognosis.
In most genetic causes the rods degenerate more than cones, leading to night blindness. They get decreased central and peripheral vision.
how does retinitis pigmentosa usually present?
Night blindness is often the first symptom
Peripheral vision is lost before the central vision.
what does fundoscopy show in retinitis pigmentosa?
Fundoscopy will show pigmentation. This is described as “bone-spicule” pigmentation. Spicule refers to sharp, pointed objects. Bone-spicule is used to refer to the similarity to the networking appearance of bone matrix.
The pigmentation is most concentrated around the mid-peripheral area of the retina.
There can be associated narrowing of the arterioles and a waxy or pale appearance to the optic disc.
what systemic diseases are associated with retinitis pigmentosa?
- Usher’s Syndrome causes hearing loss plus retinitis pigmentosa
- Bassen-Kornzweig Syndrome is a disorder of fat absorption and metabolism causing progressive neurological symptoms and retinitis pigmentosa
- Refsum’s Disease is a metabolic disorder of phytanic acid causing neurological, hearing and skin symptoms and retinitis pigmentosa
- Alports syndrome
- kearns-sayre syndrome
how is retinitis pigmentosa managed?
Referral to an ophthalmologist for assessment and diagnosis
Genetic counselling
Vision aids
Sunglasses to protect the retina from accelerated damage
Driving limitations and informing the DVLA
Regular follow up to assess vision and check for other potentially reversible conditions that may worsen the vision such as cataracts
There isn’t a huge amount of evidence supporting options to slow the disease process. Some options that may be considered by a specialist in certain scenarios include: Vitamin and antioxidant supplements Oral acetazolamide Topical dorzolamide Steroid injections Anti-VEGF injections
what are the most common causes of sudden painless loss of vision?
ischaemic/vascular (e.g. thrombosis, embolism, temporal arteritis etc). This includes recognised syndromes e.g. occlusion of central retinal vein and occlusion of central retinal artery
vitreous haemorrhage
retinal detachment
retinal migraine
what is amaurosis fugax?
loss of vision due to ischaemia or vascular problems
wide differential including large artery disease (atherothrombosis, embolus, dissection), small artery occlusive disease (anterior ischemic optic neuropathy, vasculitis e.g. temporal arteritis), venous disease and hypoperfusion
may represent a form of transient ischaemic attack (TIA). It should therefore be treated in a similar fashion, with aspirin 300mg being given
altitudinal field defects are often seen: ‘curtain coming down’
ischaemic optic neuropathy is due to occlusion of the short posterior ciliary arteries, causing damage to the optic nerve
what is papilloedema?
Papilloedema describes optic disc swelling that is caused by increased intracranial pressure. It is almost always bilateral.
what would you observe during fundoscopy in papilloedema?
venous engorgement: usually the first sign
loss of venous pulsation: although many normal patients do not have normal pulsation
blurring of the optic disc margin
elevation of optic disc
loss of the optic cup
Paton’s lines: concentric/radial retinal lines cascading from the optic disc
what can cause papilloedema?
space-occupying lesion: neoplastic, vascular malignant hypertension idiopathic intracranial hypertension hydrocephalus hypercapnia
Rare causes include
hypoparathyroidism and hypocalcaemia
vitamin A toxicity
what is herpes zoster opthalmicus?
Herpes zoster ophthalmicus (HZO) describes the reactivation of the varicella-zoster virus in the area supplied by the ophthalmic division of the trigeminal nerve
how does herpes zoster ophthalmicus present?
vesicular rash around the eye, which may or may not involve the actual eye itself
Hutchinson’s sign: rash on the tip or side of the nose. Indicates nasociliary involvement and is a strong risk factor for ocular involvement
how is herpes zoster opthalmicus managed?
oral antiviral treatment for 7-10 days
ideally started within 72 hours
intravenous antivirals may be given for very severe infection or if the patient is immunocompromised
topical antiviral treatment is not given in HZO
topical corticosteroids may be used to treat any secondary inflammation of the eye
ocular involvement requires urgent ophthalmology review
what are the complications of herpes zoster opthalmicus?
ocular: conjunctivitis, keratitis, episcleritis, anterior uveitis
ptosis
post-herpetic neuralgia
what are the stages of hypertensive retinopathy?
the keith-wagener classification is used
what can cause mydriasis?
mydriasis (large pupil) third nerve palsy Holmes-Adie pupil traumatic iridoplegia phaeochromocytoma congenital
Drug causes of mydriasis
topical mydriatics: tropicamide, atropine
sympathomimetic drugs: amphetamines, cocaine
anticholinergic drugs: tricyclic antidepressants
what can cause tunnel vision?
papilloedema glaucoma retinitis pigmentosa choroidoretinitis optic atrophy secondary to tabes dorsalis hysteria
