Ophthalmology Flashcards
What are the causes of a painful acute red eye?
Acute angle-closure glaucoma
Anterior uveitis
Scleritis
Corneal abrasion/ulceration
Keratitis
Foreign body
Traumatic/chemical injury
What are the causes of a painless acute red eye?
Conjunctivitis
Episcleritis
Subconjunctival haemorrhage
What is glaucoma?
Damage to the optic nerve due to raised intraocular pressure due to a blockage as aqueous humour tries to escape the eye
What are the anterior and posterior borders of the anterior chamber of the eye?
Cornea anteriorly
Iris posteriorly
What are the anterior and posterior borders of the posterior chamber of the eye?
Iris anteriorly
Lens posteriorly
What is the normal physiological route of aqueous humour?
Produced by ciliary body
Supplies the cornea with nutrients
Flows through the posterior chamber and iris into the anterior chamber
Drains through the trabecular meshwork into the canal of Schlemm
Enters the general circulation
What is normal intraocular pressure?
10-21 mmHg
How does open-angle glaucoma happen?
Gradual increase in resistance to flow through the trabecular meshwork
Pressure slowly builds in the eye
What can be seen on fundoscopy in open-angle glaucoma?
Increased cupping of the optic disc (cup-disc ratio of greater than 0.5)
What are risk factors for open-angle glaucoma?
Increasing age
Family history
Black ethnic origin
Myopia (nearsightedness)
How does open-angle glaucoma present?
May be asymptomatic for a long time before diagnosis on routine eye test
Affects peripheral vision first, causing tunnelling
Fluctuating pain
Headaches
Blurred vision
Halos around lights, particularly at night
What is the first-line medical management for open-angle glaucoma?
Prostaglandin analogue eye drops (e.g., latanoprost) –> Increase uveoscleral outflow
What other medications can be used to treat open-angle glaucoma?
Beta-blockers (e.g., timolol) –> reduce production of aqueous humour
Carbonic anhydrase inhibitors (e.g., dorzolamide) –> reduce production of aqueous humour
Sympathomimetics (e.g., brimonidine) –> reduce production of humour and increase uveoscleral outflow
What is the NICE guidelines’ first line management for all open-angle glaucoma patients requiring treatment?
360° selective laser trabeculoplasty
What is the intraocular pressure treatment threshold in open angle glaucoma?
24mmHg
What is the pathophysiology of acute angle-closure glaucoma?
Increased pressure causes iris to bulge forward, closing the trabecular meshwork
This causes pressure to continue to build, further worsening the angle closure
What are the risk factors for acute angle-closure glaucoma?
Increasing age
Family history
Female
Chinese and east Asian ethnic origin
Shallow anterior chamber
Medication e.g., noradrenaline, anticholinergics, tricyclic antidepressants
How does acute angle-closure glaucoma present to the patient?
Severely painful red eye
Blurred vision
Halos around light
Associated headaches, nausea and vomiting
What are the signs of acute angle-closure glaucoma?
Red eye
Hazy cornea
Decreased visual acuity
Mid-dilated, fixed size pupil
Hard eyeball on palpation
What is the initial management of acute angle-closure glaucoma?
Immediate blue light admission
Lie patient on their back
Pilocarpine eye drops (2% for blue, 4% for brown)
Acetazolamide 500mg
Analgesia and antiemetic if required
How is acute angle-closure glaucoma managed in secondary care?
Pilocarpine eye drops
Acetazolamide
Hyperosmotic agents (e.g., IV mannitol) –> increase the osmotic gradient between blood and eye, aiming to draw fluid out of the eye
Timolol –> reduce humour production
Carbonic anhydrase inhibitors (e.g., dorzolamide) –> reduce production of aqueous humour
Sympathomimetics (e.g., brimonidine) –> reduce production of humour and increase uveoscleral outflow
What is the definitive management of acute angle-closure glaucoma?
Laser iridotomy –> hole is made in the iris to allow aqueous humour to move from the posterior to anterior chamber, relieving the pressure
What is blepharitis?
Inflammation of the eyelid margins
What is the presentation of blepharitis?
Gritty, dry sensation of the eyes
What is the management of blepharitis?
Warm compression and gentle cleaning
What is a stye?
Infection of the glands in the eyelids
What is the management of a stye?
Hot compression and analgesia
Topical antibiotics (e.g., chloramphenicol if symptoms present or conjunctivitis
What is a chalazion?
Blockage of the meibomian gland
What is an entropion?
When the eyelid turns inwards and lashes are against the eye
What is an ectropion?
When the eyelid turns outwards, exposing the inner aspect
What is trichiasis?
Inwards growth of eyelashes
What is periorbital cellulitis?
Eyelid infection anterior to orbital septum
How does periorbital cellulitis present?
Swollen, red, hot skin around eyelid and eye
What is the management of periorbital cellulitis?
Systemic antibiotics
Monitor progression to orbital cellulitis (medical emergency)
What is orbital cellulitis?
Eyelid infection posterior to orbital septum
Medical emergency
How does orbital cellulitis present?
Painful and reduced eye movement
Vision changes
Abnormal pupil reactions
Bulging of the eyeball
What is the management of orbital cellulitis?
Emergency admission
IV antibiotics
Surgical drainage if abscess forms
What are cataracts?
Progressive increasing of opaqueness of the lens, reducing the light entering the eye and reducing visual acuity
How are congenital cataracts screened for?
Red reflex test
What are risk factors for cataracts?
Increasing age
Smoking
Alcohol
Diabetes
Steroids
Hypocalcaemia
How do cataracts present?
Slow reduction in visual acuity
Usually asymmetrical
Progressive vision blurring
Fading of colour vision
Starbursts around light
How are cataracts managed?
No intervention necessary if symptoms are manageable
Cataract surgery
What is a rare but serious complication of cataract surgery?
Endophthalmitis = Inflammation of the inner contents of the eye
Managed with intravitreal antibiotics
Where does the central retinal artery branch from?
Ophthalmic artery, which branches from the internal carotid artery
What are causes of central retinal arterial occlusion?
Atherosclerosis
Giant cell arteritis
What are risk factors for central retinal arterial occlusion?
(From atherosclerosis)
Smoking
Hypertension
Diabetes
Hypercholesterolaemia
(From GCA)
White ethnicity
Older age
Female
Polymyalgia rheumatica
How does central retinal arterial occlusion present?
Sudden painless loss of vision (“curtain coming down”)
What are the differentials of sudden painless vision loss?
Retinal detachment
Central retinal arterial occlusion
Central retinal vein occlusion
Vitreous haemorrhage
Amaurosis fugax
What are the signs of central retinal arterial occlusion?
Relative afferent pupillary defect (pupil in affected eye constricts more when light is shone in the other eye than when light is shone in the affected eye)
Pale retina with cherry red spot on fundoscopy
What is the management of central retinal arterial occlusion?
Immediate referral
High-dose prednisolone if suspected due to GCA
What are the causes of conjunctivitis?
Bacterial –> Staphylococcus, strep pneumoniae, haemophilus influenzae
Viral –> Adenovirus, HSV, VZV
Allergic
How does conjunctivitis present?
Red, bloodshot eye
Itchy or gritty sensation
Discharge –> purulent if bacterial, clear if viral
What symptoms suggest that a red eye is NOT conjunctivitis?
Pain
Photophobia
Reduced visual acuity
What is the management of conjunctivitis?
Usually resolves in 1-2 weeks without treatment
Hygiene measures to prevent spreading as it is highly contagious
Clean the eye with cooled boiled water and cotton wool
Chloramphenicol or fusidic acid eye drops if indicated in bacterial cause
How can diabetes cause retinopathy?
Hyperglycaemia damages the retinal small vessels and endothelial cells
Increased vascular permeability causes leaking blood vessels and hard exudates
Damage to vessel walls causes microaneurysms and venous beading
Damage to nerve fibres forms cotton wool spots to form on the retina
Intraretinal dilated and tortuous capillaries form, acting as a shunt between arterial and venous vessels
The release of growth factors stimulates neovascularisation
What are the complications of diabetic eye disease?
Vision loss
Retinal detachment
Vitreous haemorrhage
Rubeosis iridis –> new blood vessels form in the iris, causing neovascular glaucoma
Optic neuropathy
Cataracts
What features on fundoscopy suggest background diabetic eye disease?
Microaneurysms
Retinal haemorrhage
Hard exudates
Cotton wool spots
What features on fundoscopy suggest pre-proliferative diabetic eye disease?
Venous beading
Multiple blot haemorrhages
Intraretinal microvascular abnormality
What features on fundoscopy suggest proliferative diabetic eye disease?
Neovascularisation
Vitreous haemorrhage
What is the management of non-proliferative diabetic eye disease?
Close monitoring
Careful diabetic control
What is the management of proliferative diabetic eye disease?
Pan-retinal photocoagulation (laser treatment to suppress new vessels)
Intravitreal anti-VEGF medication
Surgery e.g., vitrectomy
What are some complications of pan-retinal photocoagulation?
Reduction in visual fields
Decrease in night vision
General decrease in visual acuity
Macular oedema
What is infective keratitis?
Inflammation of the cornea
What are the causes of infective keratitis?
Viral –> herpes simplex
Bacterial –> pseudomonas, staphylococcus
Fungal –> candida, aspergillus
Contact lens induced red eye (CLARE)
Exposure –> e.g., with ectropion
What is the most common cause of infective keratitis?
Herpes simplex virus
How does infective keratitis present?
Primary –> Mild inflammation of the eyelid margins and conjunctiva
Recurrent –> Painful red eye, photophobia, vesicles, foreign body sensation, watery discharge, reduced visual acuity
What is the management of infective keratitis?
Referral for urgent assessment
Topical or oral antivirals –> aciclovir or ganciclovir
Corneal transplant to treat permanent scarring and vision loss
What are the 2 subtypes of macular degeneration?
Wet/neovascular –> 10%
Dry/non-neovascular –> 90%
What are the risk factors for macular degeneration?
Older age
Smoking
Family history
Cardiovascular disease
Obesity
Poor diet
How does macular degeneration present?
Unilateral, gradual loss of central vision
Reduced visual acuity
Crooked or wavy appearance of straight lines
What is the management of macular degeneration?
Dry –> No treatment, manage risk factors
Wet –> Anti-vascular endothelial growth factor medication intravitreally
What is the pathophysiology of retinal detachment?
Retinal tear allows vitreous fluid to get under the neurosensory retina and separate it from the retinal pigment epithelium and choroid
The neurosensory retina relies on the choroid for blood supply, so detachment disrupts the blood supply
What are the risk factors for retinal detachment?
Lattice degeneration (retinal thinning)
Posterior vitreous detachment
Trauma
Diabetic retinopathy
Retinal malignancy
Family history
How does retinal detachment present?
Painless
Peripheral vision loss
Blurred or distorted vision
Flashes/floaters
What is the management of retinal detachment?
Immediate referral
Retinal tears –> Aim to re-adhere the retina and choroid with cryotherapy or laser therapy
Retinal detachment –> Reattach the retina and reduce any pressure that could cause it to re-detach
What is scleritis?
Inflammation of the sclera (the connective tissue that surrounds the eye)
What are the causes of scleritis?
Idiopathic
Associated with underlying systemic inflammatory cause e.g., rheumatoid arthritis and vasculitis (granulomatosis with polyangiitis)
Infection –> pseudomonas or staph aureus
How does scleritis present?
Gradual onset
Red inflamed sclera
Severe pain, including with eye movement
Photophobia
Excessive tear production
Reduced visual acuity
What is the management of scleritis?
Urgent referral
Screen for underlying systemic inflammatory cause
NSAIDs
Steroids
Immunosuppression
Antimicrobials if infective
What is episcleritis?
Benign, self-limiting inflammation of the episclera (the outermost layer of the sclera just below the conjunctiva)
What is episcleritis often associated with?
Inflammatory disorders such as rheumatoid arthritis and inflammatory bowel disease
How does episcleritis present?
Acute onset and unilateral
Redness
No pain
Dilated episcleral blood vessels
No photophobia
Normal visual acuity
How can episcleritis be distinguished from scleritis?
Episcleritis does not cause pain, photophobia or reduced visual acuity
Phenylephrine drops blanch the episcleral vessels but do not affect scleral vessels
What is the management of episcleritis?
Self limiting and will resolve in 1-2 weeks
Severe cases may require steroid drops
What is anterior uveitis?
Inflammation of the iris, ciliary body and choroid
What conditions are associated with anterior uveitis?
Seronegative spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis, reactive arthritis)
How does anterior uveitis present?
Painful red eye (redness that spreads from the iris)
Reduced visual acuity
Photophobia
Excessive lacrimation
What is the management of anterior uveitis?
Urgent assessment
Steroids
Cycloplegics (e.g., cyclopentolate or atropine eye drops) –> dilate the pupil and reduce ciliary spasm
Recurrent cases may required DMARDs or anti-TNF medications
