Opthalmology Flashcards
What causes glaucoma?
Optic nerve damage that is caused by a significant rise in intraocular pressure due to a blockage in aqueous humour trying the escape the eye
What are the 2 types of glaucoma?
Open angle and closed angle
Where is aqueous humour produced?
The ciliary body
What is normal intraocular pressure?
10-21 mmHg
What happens in acute angle-closure glaucoma?
The iris bulges forward and seals off the trabecular meshwork (where the aqueous humour drains) which leads to a continuous build up of pressure. This is an ophthalmology emergency
What is “cupping” in glaucoma?
caused by increased in pressure in the eye. In the centre of the optic disc is an optic cup. When there is raised intraocular pressure the indent becomes larger and the cup becomes wider and deeper. A cup greater than 0.5 the size of the optic disc is abnormal
How does open angle glaucoma present?
Affects peripheral vision first which gradually closes in until it becomes tunnel vision
Fluctuating pain, headaches, blurred vision and halos of light appearing, especially at night
How can intraocular pressure be measured?
Non-contact tonometry (the puff of air test)
Goldmann applanation tonometry (gold standard)
How is glaucoma diagnosed?
Goldmann applanation tonometry
Fundoscopy
Visual field assessment
When is treatment commenced in glaucoma?
When the pressure is greater than 24mmHg
What is the management for open angle glaucoma?
Prostaglandin analogue eye drops - lantanoprost
Beta-blockers (timolol) reduce the production of aqueous humour
Carbonic anhydrase inhibitors (dorzolamide)
Trabeculectomy
What are the notable side effects of prostaglandin analogue eye drops?
Eyelash growth
Eyelid pigmentation
Iris pigmentation (browning)
Which medications can precipitate acute angle-closure glaucoma?
Adrenergic medications such as noradrenalin
Anticholinergic medications such as oxybutynin and solifenacin
Trycyclic antidepressants such as amitriptyline
How does acute angle-closure glaucoma present?
Severely painful red eye
Blurred vision
Halos around lights
Associated headache, nausea and vomiting
What does an eye with acute angle-closure glaucoma look like?
Red-eye Teary Hazy cornea Decreased visual acuity Dilatation of the affected pupil Fixed pupil size Firm eyeball
How should acute angle-closure glaucoma be managed?
Lie patient on back without pillow
Give pilocarpine eye drops (2% blue eyes, 4% brown eyes)
Oral or IV acetazolamide which is a carbonic anhydrase inhibitor
Laser iridotomy is the definitive treatment
What is the key finding associated with macular degeneration which is found on fundoscopy?
Drusen
What are the 2 types of age related macular degeneration?
Dry (90%) and Wet (10%)
Wet has worse prognosis
What is the presentation of macular degeneration?
Gradual worsening of central visual field loss
Reduced visual acuity
Crooked or wavy appearance to straight lines
How can macular degeneration be investigated?
Snellen chart
Scotoma (central patch of visual loss)
Amsler grid test (crooked straight lines)
Fundoscopy (drusen)
What is the management for dry macular degeneration?
Avoid smoking
Control blood pressure
Vitamin supplementation
What is the management of wet macular degeneration?
Anti- VEGF medications injected directly into the vitreous chamber.
What causes diabetic retinopathy?
The retina are damaged by prolonged exposure to hyperglycaemia. Vessels become leaky leading to microaneurysms and venous beading
Damage to nerve fibres causes fluffy white patches called cotton wool spots
What are the two categories of diabetic retinopathy?
Proliferative and non-proliferative
What is the management of diabetic retinopathy?
Laser photocoagulation
Anti-VEGF medications
What are the signs in the retina which are caused by hypertensive retinopathy?
Silver wiring or copper wiring (walls of the arterioles become thickened)
Ateriovenous nipping
Cotton wool spots
Retinal haemorrhages
Papilloedema
What is the classification system for hypertensive retinopathy?
Keith-Wagener Classification
What are cataracts?
The lens in the eye becomes cloudy and opaque. This reduces the visual acuity by reducing he light which enters the eye
How are congential cataracts screened for?
By checking the red reflex in neonatal examination
What are the risk factors for cataracts?
Increasing age Smoking Alcohol Diabetes Steroids Hypocalcaemia
What is the presentation of cataracts?
Very slow reduction in vision
Progressive blurring of vision
“starbursts” can appear around lights, particularly at night
How are cataracts managed?
Surgical removal and replacement
What is the serious complication of cataract surgery and how is it managed?
Endophtalmitis- inflammation of the inner contents of the eye, usually due to infection.
Treated by intravitreal antibiotics
What does a 3rd nerve palsy cause?
Ptosis
Dilated non-reactive pupil
Divergent strabismus
Which muscles does the 3rd nerve supply?
All of the extraocular muscles except the lateral rectus and superior oblique
Also supplies the levator palpaebrae superioris
What does a third nerve palsy with sparing of the pupil suggest?
A microvascular cause because the parasympathetic fibres are spared
What does a full nerve palsy suggest?
Physical compression
What are the features of horner syndrome?
Ptosis
Miosis
Anhidrosis
What is damaged in horner’s syndrome?
The sympathetic nervous system
What is the relation between the location of the lesion and anhydrosis?
Central lesion= anhydrosis of the arm and trunk as well as the face
Pre-ganglionic= anhydrosis of the face
Post-ganglionic= do not cause anhydrosis
How is horner’s syndrome tested for?
Cocaine eye drops. Causes a normal pupil to dilate but not in horner’s
What is holmes adie pupil?
Dilated pupil which is sluggish to react to light with slow dilatation of the pupil following constriction. Over time the pupil will get smaller. This is caused by damage to the post ganglionic fibres
What is Argyll-Robertson pupil?
Finding in neurosyphilis
No light reflex but does have an accommodation.
What is blepharitis?
Inflammation of the eyelid margins
What is the management if blepharitis?
Hot compresses, gentle cleaning and eyedrops
Polyvinyl alcohol is the eyedrops people start with
What is a Stye?
Infection of the glands of zeis or glands of Moll. Presents as a tenser red lump along the eyelid which may contain pus
How are styes managed?
Hot compresses, analgesia and chloramphenicol
What is an entropion?
The eyelid turns inwards so the eyelashes are against the eyeball
What are the complications of entropion?
Corneal damage and ulceration
What is the management of entropion?
Initially taping the eyelid down to prevent it turning inwards. Definitive management is with surgical intervention
What is ectropion?
The eyelid turns out so the inner aspect of the eyelid is exposed
What is a complication of ectropion?
Exposure keratopathy
What is the management of ectropion?
Lubricating eyedrops
May require surgery
How are periorbital and orbital cellulitis differentiated?
CT scan
How is periorbital cellulitis managed?
systemic antibiotics
What are the 3 types of conjuctivitis?
Bacterial
Viral
Allergic
How does conjuctivitis present?
Red eyes
Bloodshot
Itchy or gritty sensation
Discharge from the eye
How does the discharge look different between bacterial and viral conjunctivitis?
Bacterial is purulent
Viral presents with clear discharge
How is conjuctivitis managed?
Usually resolves without treatment after 1 or 2 weeks
Use cooled, boiled water and cotton wool
Choramphenicol and fuscidic acid eye drops
What is anterior uveitis?
Inflammation in the anterior part of the uvea. The uvea involves the iris, ciliary body and choroid. It involves inflammation and immune cells in the anterior chamber of the eye
Which conditions is anterior uveitis associated with?
HLA b27 conditions:
Ankylosis spondylitis
Inflammatory bowel disease
Reactive arthritis
How does anterior uveitis present?
Unilateral symptoms Dull, aching, painful red eye Ciliary flush Miosis Photophobia Lacrimation Hypopynon (you can see the collection of white cells in the iris as a fluid line) Floaters
What is the management of anterior uveitis?
Steriods
Cycloplegic-mydriatic medications
What is episcleritis?
Self limiting inflammation of the episclera
What is the presentation of episcleritis?
Not painful
Segmental redness
Foreign body sensation
What is the management of episcleritis?
Should resolve in 1-4 weeks
Analgesia, cold compresses and safetynet advice
What is scleritis?
Inflammation of the full thickness of the sclera
How does scleritis present?
Severe pain Pain with eye movement Photophobia Eye watering Reduced visual acuity Abnormal pupil reaction to light Tenderness to palpation of the eye
What is the management of scleritis?
NSAIDs
Steroids
Immunosupression
If a corneal abrasion is caused by contact lenses, what is the likely causative organism?
Pseudomonas
How is corneal abrasion diagnosed?
Flurorescein stain
How is corneal abrasion managed?
Simple analgesia
Lubricating eyedrops
Abx eyedrops (chloramphenicol)
What is keratitis?
Inflammation of the cornea
What is the most common cause of keratitis?
Herpes simplex keratitis
How is herpes keratitis diagnosed?
Fluroescein stain will show a dendritic corneal ulcer
Slit-lamp examination is required to diagnose keratitis
How is herpes keratitis treated?
Aciclovir
Ganciclovir
Steroids
What is the presentation of posterior vitreous detachment?
Painless
Spots of vision loss
Floaters
Flashing lights
What is the presentation of retinal detachment?
Peripheral vision loss
Blurred vision
Flashes and floaters
What is the presentation of retinal vein occlusion?
Sudden, painless loss of vision
What are the fundoscopy results for retinal vein occlusion
Flame and blot haemorrhages
Optic disc oedema
Macula oedema
What is the management of retinal vein occlusion?
Laser photocoagulation
Intravitreal steroids
Anti-VEGF therapies
How does blockage of the central retinal artery present?
Sudden painless loss of vision
Relative afferent pupillary defect
What is seen on fundoscopy when there is central retinal artery occlusion
Pale retina with a cherry red spot
What can be a cause of central retinal artery occulsion?
Giant cell arteritis
How is central retinal artery occlusion managed?
Removing fluid from anterior chamber
Inhaling carbogen to dilate the artery
What is the presentation of retinitis pigmentosa?
Night blindness
Peripheral vision is lost before central vision
What is seen on fundoscopy in Retinitis pigmentosa
Bone-spicule
